3DR Solo Battery charging adapter and diagnostics tool.

Buy Solo Battery Tool ($45)

Ver 1.3 is out ! ¬† ūüôā

3DR Solo battery packs have lots of information that the average user will never see, they are also very nicely calibrated for voltage (cells and pack) as well as current.

Some of the information, like capacity, cell voltages, cycles, past low voltage condition, cell voltage difference  and manufacture date may be very useful.

Health data is very useful as well.

Below: two devices, one as delivered, the other with an XT60 connector for charging.

It’s easy to solder on XT60, charger cables, or other connectors right on the main connector. The XT60 is there just for illustration purposes, it’s easy to solder on most of the typical connectors (XT60, EC3) directly, the rest can be soldered on with wires.

The device is not doing any calculations on it’s own, data is read from the battery, and presented.


Values and information details:

Pack Voltage
Charge level in %
Remaining capacity
Internal temperature.
Charging current. (Negative value indicate discharging current)


Cell voltages for cell 1…4 – should be self-explaining, any healthy pack will have very similar voltages after a flight.
Design capacity is what the pack was designed to be.
Actual capacity is shows the actual capacity as the pack ages.
Relative charge level is based on actual capacity of the pack.
Absolute charge level is based on design capacity of the pack.


Manufacturing date in Y-M-D format.
Made by BMTPOW
Device name is MA03, serial number follows (not the same as barcode on the pack)
TTF: Time To Full , if not charging, will display “-1”
Cycles: how many times have this pack been used. This is increased when discharged_capacity_since_last_increase > design_capacity.

Status word is bitmapped at least two bits we know are used, one indicating charging/discharging , the other tell if the factory calibration data is OK.

Should factory calibration data ever be corrupted, then you can never know if a reported voltage/current (used for capacity calculation !) is correct, and it’s dangerous to fly with such pack. A very clear warning will be displayed.

There is also a warning for internal resistance deviation.
There is a “Cell Change” warning, I do not know what can cause it, or what exactly it means – both warnings above are for illustration purposes, I have no packs with such condition.

Status is expected to be 128(charging) or 192(discharging)  , 16608 is a fully charged battery. (Thanks to Bob that found that).
Health is 18 for all good packs (I do not have one that is bad) , but there are 16bit of data that can indicate quite a lot…

I’ll update this page based on user reports.

Lowest voltage record.
– Displays eight last low voltage records, some values are initialized as 3.5v , but it is the lowest values that indicate if the battery have ever been close to deep-discharge.


If battery pack is connected, but not charging – after 180seconds, the DONE message will show, two minutes later the battery will switch off.

Serial output:

This dataset is output to the same FTDI interface:

Data is output on the serial interface at 115200baud, at 1hz.

This allows for nice graphing of charging/discharging, and full monitoring using Dataexplorer¬†with the plugin I’ve made:¬†Solo_Batt_Tool.xml

Of course, you are free to do whatever logging you wish, the format is basically semicolon delimited, and temperature, cell voltages are multiplied with 100/1000 so you don’t need to parse thru commas.

The format is:



$1 ;1 ;20988; 1550; 0; 52; 52;2724;2445;3874;3874;3875;3876;105;26;76;-1;8;0




Plug into battery , switch on battery.
Plug into battery , and provide charging current.  You can use any standard charger, select Li-Po 4cell program with no balancing (the smart battery does the rest)


Firmware upgrade:

There is an custom bootloader on the device, so if the community or I figure out more about the battery, it’s possibly to upgrade it using a standard FTDI cable and the avrdude tool (for Linux,Mac,Windows).

FTDI cable, with extra pin header.


Insert pin header into FTDI cable, the protruding, short pins will fit into the SoloBatt_OLED’s ¬†six pins on the edge of the PCB. ¬† You will need to cut away, or puncture a little bit of shrink-wrap to access the edge.

The upper & lower  of the six pins on PCB, are marked BLK (black) and GRN(green)  Рmake sure that matches the orientation of the FTDI cable. (reversing does no damage)

Observe that there are two files in the firmware package:

“VG” is for displays with pin order: “VCC, GND, SCL, SDA”¬†
“GV” is for displays with pin order: “GND, VCC, SCK, SDA”

To write the new firmware you will  need avrdude application.

On Linux, it’s installed by: ¬†“sudo apt install avrdude”

The firmware upload command is:

avrdude -patmega328p -carduino -P /dev/ttyUSB0 -b115200 -D -Uflash:w:SoloBatt_OLED.1.1.hex :i

/dev/ttyUSB0 is most likely correct, the number will be higher if you have more than one USB serial device

If you are using windows, replace /dev/ttyUSBx o COMx ¬†, also, in windows you’ll need some FTDI drivers.

Please note that the programming protocol is arduino compatible just enough to make it work with avrdude,¬†but it’s not really arduino.

Firmware 1.1

  • Longer auto-off delay (was 2min , now 4min)
  • Longer time per screen 3s->6s
  • Serial output using FTDI cable at 115200 baud


Firmware 1.2

  • Warning if battery has detected uneven internal resistance.
  • Warning named “change cell” (not sure when that is supposed to kick in)
  • Low voltage records.
  • Three digits in cell voltages.
  • Fahrenheit & Celsius temperature.

Firmware 1.3

  • Serial logging for Dataexplorer plugin (and any other data collection).
  • Shorter splashscreen timeout.
  • Cosmetic fix for long status numbers on OLED display.
  • manual page flip. lets user skip forward to a certain page, and stops automatic rotation. ¬†(connect momentary switch between pin8 and pin9 – or – if you are using a microcontroller , just pull pin9 low.)

Download: SoloBatt_OLED_v1.3

Sony QX1 Focus/Trigger control for drone use.

 RC, PWM control for QX1.

Buy QX1 modification service ($150)

Sony ILCE-QX1 has great specifications at low weight, which makes it good for UAV photogrammetry use. ¬†It can be configured using WiFi , then retain the configuration. (so it’s not necessary to even enable wifi for each operation.

About the modification:

The pop-up flash assembly is removed, an microcontroller replaces the flash assembly, it’s interfacing the motherboard indirectly, via FPC. The flash cover is slightly cut to make space for the servo (PWM input) ¬† and logic level output that indicates shutter operation.

Can reliably do manual-focus shoot every 700ms. (no drops)

The camera will continue to function normally as before when the PWM interface is not supplied with power, except for the flash.

The modification requires micro-soldering; most narrow are three points within 1mm distance. Naturally, it voids camera warranty. (so test camera well before getting it modified.)

Features of the modification:

  • Camera will not shut down when inactive..
  • 3-wire servo connector (PWM input)
  • 1-wire logic output (high on shutter) -allows precise GPS positioning of each photo, and confirmation to the AP that photo is taken.
  • Command “Shoot” (just trigger a photo, for preset/manual focus)
  • Command “autofocus for 500ms, then shoot”
  • Command “autofocus for 1s, then shoot”


Suggested ArduPilot setup:

CAM_FEEDBACK_PIN (set to correct input)


PWM Commands:

990us … 1400us = Shoot instantly (manual focus)
1401us … 1600us = Idle
1601us … 1800us = autofocus 0.5s , shoot
1801us … 2200us =autofocus 1s , shoot

I can convert your camera, or buy+modify one.

Contact for more information.

PWM>FLIR: Control FLIR TAU, TAU2, Quark using PWM (RC Radio)


A quick demo, switching between 8 modes using a servo-tester. The TAU640 in this video is set for outdoor use, and does not show the full advantage of Ice&Fire modes inside.



What you get:

  • A microcontroller on a small PCB (18x33x3mm) with soldering pads. Preprogrammed with 8 different modes as in this video, or up to 10 custom modes (as ordered).
  • The circuit works on 5v, uses less than 10mA.¬† You can connect it using 3 wires,¬† just like a servo)
  • The modes are selected using a knob on your transmitter, PWM decide mode, just like a servo position.
  • Serial data, is sent from the device to your FLIR device using one wire – (assuming you have common ground)
  • The common modes in this test video shows 8 modes I’ve found very useful.

What you need:

  • FLIR TAU ,TAU2, or QUARK thermal core.
  • For TAU,¬† “Wearsaver” helps a lot.¬† – It offers big soldering pads for connecting to the Hirose 50p connector. RX(pin2)
  • For Quark , you need to connect the serial signal to pin 15 of the Samtec 60 pin – connector. or to the breakout board, if you that.

Connection instructions:

Connect PWM (white wire) from your receiver to pad9 on PWM>FLIR device
Connect “-” (black wire) from your receiver to GND on the PWM>FLIR device
Connect “+” (red wire) from your receiver to VCC on the PWM>FLIR device

Connect pad8 on the device to your RX pad on wear saver, thats solder pad with green ring in the picture below.
Connect ground and +5v to TAU (black and red pads in picture below)

Finally, for information only:composite video out is on the yellow pad, and video ground on the blue pad on the TAU wearsaver.

TAU Wearsaver connection

Default mode configuration is:

1, white hot, no zoom , spatial threshold gain 34d.
2 white hot, 2x zoom, spatial threshold gain 34d.
3 Black Hot, no zoom , spatial threshold gain 34d.
4 Black Hot, 2x zoom, Spatial threshold = 9d
5 Fusion,no zoom, spatial threshold gain 34d.
6 ICE & Fire, no zoom, spatial threshold gain 34d.
7 Rainbow, no zoom, Spatial threshold, Gain = 34d
8 ICE & Fire, no zoom , Spatial threshold 17d

You can output a PWM from an autopilot, controlled by GCS, having any GUI you prefer.¬† – Or , if¬† you are will be controlling the PWM directly from a RC radio, you¬† do not need a rotary knob with steps, it’s perfectly easy to hit desired mode even with smooth knob due to the quick visual change, and equal “distance” between modes.

Buy PWM>FLIR interface ($160)

(Cart will appear below)

CryptoTelemetry – Secure firmware to prevent drone hijacking.

The CryptoTelemetry firmware:

Due to the proven vulnerability of current telemetry modules, I’ve developed something significantly stronger.

The source is not open, because it’s not real strong, certificate-based encryption, that allows end-user to replace, create new certificates. One advantage of doing it this way, is that you can purchase more radios and add them without having to reprogram all.

The secrets are permanently stored inside, and opening the source would give glues of possible attack vectors.  I intended this to be a long time viable, secure solution.

Still – the owner have the option to get more radios that will work with his private network.


  • 433,470,863,915Mhz support.
  • Fully compatible with all ground station configuration tools.¬† All the common AT commands and parameters are there, there’s even a NetID that will let you make different networks within your encrypted network – should you wish.¬† Example, if you have 4 CryptoTelemetry radios,¬† you can have 3 in different UAV’s , all have the same network ID, and will speak to the same GCS, typical use is “one at a time”. Or you can set two radios with NetID different than the others, and use two GCS and two UAV simultaneously. – Note that no non-CryptoTelemetry radios will be able to communicate with these radios.
  • Locked down firmware, even if one malicious customer purchased it for analysis, it would be hard to learn anything from it.¬† – Then it would take some time to find your encryption key.
  • Personal encryption key.¬† (most tend to be 11digits) Only the customer will have the key, it is NOT stored here. To order more radios for the same network, it’s essential to provide the key so a properly encrypted firmware for your radio can be generated.
  • Your radios will operate in your network, no one else will be able to see the data, or encrypt without some extensive cryptanalysis and hacking.
  • Encryption can be disabled by disabling ECC – radios enter then a transparent mode, which is 2x the usual ECC data rate.
  • Efficient; the data rate is the the same as ECC,¬† (half of the non-ECC speed.)
  • ECC (Golay24) is still active, for every 12bit , up to 3 bit errors can be corrected.
  • Delivered on standard, authentic, genuine 3DR telemetry radios.
  • If customer provides radios, it can be flashed onto a several other/compatible radios.
  • Reversible – should this method be obsolete one day, it is fully possible to convert these radios to run official 3DR provided firmware.

I am using this firmware for all my commercial operations as well as hobby flights, it is well tested.

Get your radio reprogrammed with CryptoTelemetry ($85):

Buy new original 3DR Radio with CryptoTelemetry ($135):


How to hijack a drone by telemetry ‚Äď and prevent it.

My professional background is network and Internet security, I quickly discovered the huge risk of an hostile takeover of UAV midair.

My experiment is based on 3DRobotics telemetry radios. but works with many more radios, based on the same, open, solution.

Please note that this is not a security risk of Ardupilot project, ArduCopter, ArduPlane is *not* to blame.¬† You may get an idea that some changes should not be allowed while armed, but that’s not a proper solution. Having all the options we have, after all, GCS is a device to be trusted, and the primary control during a auto mission.

Radios lack proper security, mostly due to limited processing power for proper encryption.  We are left with an simple attempt to secure the data, which is very easily worked around.

The open nature of the project, makes it impossible to truly protect the transmitted data. The radios do not have space & processing power to use  public&private  certificate based verification of data, also we would need a simple and a method of letting users selv-sign/generate such certificates for as many radios they needed in a network.

The current attempt to secure the transmission is based on radios dropping packets branded with different NetID- and the frequency hopping pattern to be seeded by the NetID.

So knowing or guessing one UAV’s (or companies) NetID, (provided it’s even changed from the default one) , enables anyone to send packets that are perfectly valid on the network.

To verify the theory, I needed an experiment:

I created a specialy crafted firmware for the stock¬† telemetry radio, it proved to be a trivial task, Let’s call the module for BlackSheep, it have the following features:

  • Automatic sniffing of nearby NetID (as we know, the user-set NetID is also used to seed the frequency hopping)
  • When it finds valid packet with NetID, it learns active frequencies, and changes it’s frequency hopping to the pattern of that particular NetID – locking in on it. – whole process takes ~1second.
  • By connecting BlackSheep to any GCS, we have instantly a valid connection to a nearby operating UAV.

Hijacking the drone in real life.

We can assume a low-tech drone hijacker would do it by running a GCS and just do it manually. An intermediate hacker would use scripts with MavProxy, or clicking around in GCS software – but the optimal solution, is a predefined set of commands used by a modified GCS for easy map interaction.:

This is what an takeover looks like;

  • pointlessly evil hijacker could just disarm the drone midair or send MAV_CMD_DO_FLIGHTTERMINATION – but that’s not the goal here.
  • send, and repeat a few times: SR?_* = 0¬† – disables all telemetry output from AP , make the radio go silent.¬† This will also reduce amount of packet collisions if we have 3 radios operating. (UAV is the one occupying most of the radio time) – now the victim GCS operator does not¬† get any more updates.
  • Then we set all control FLIGHTMODE_? to AUTO or Guided (by preference),¬† and disable FS_Throttle and FS_GCS , CH6 and other programmable options are disabled. The pilot with RC can’t do anything anymore.
  • Enabling SR?_EXT_STAT – gives the hijacker RAW GPS data, altitude, speed – this data is usually not visible on a GCS, so the victim can’t see it – but hijacker knows where the UAV is.
  • Uploading a mission, or Guided mode instructions sends the UAV to wherever hijacker wants – victim have no valid input, and cannot see it in GCS, all he gets is Mavlink heartbeat.
  • Finally, for the extra evil touch hijacker can inject Mavlink MAVLINK_MSG_ID_GLOBAL_POSITION_INT packets (as if autopilot was sending it) with proportionally incorrect data, so we could get the victims GCS display and log the real movement, with actual speed, but in different direction, misguiding as to where the UAV went.

I skipped a few trivial steps, like setting higher cruise-speed, and few platform dependent commands – but the short summary should be frightening enough.

What can be done to prevent such hijacking ?

  • Fly without telemetry radio, reducing mission control and control redundancy, not good.
  • Use cellular network to get TCP or UDP control, limited coverage.
  • Use wifi, very poor range.
  • Satellite modem, expensive, very low data rate, often ~2400bps
  • Continue to develop open solutions with hardware limitations that limits us to very simple security solutions, like the one in use today – very easy to circumvent.
  • Use customized, specialized, closed solution that offers good security, it is not proper certificate based encryption, but rather an odd, but very effective scrambling.¬† Effective mostly because the firmware is locked down, and not easy to analyze.

Final words:

Telemetry radios , 433/900Mhz are great, most aviation authority approved approved flights , professional or hobby, are within VLOS, where these radios perform great.

The fact the source i open, is not a drawback, but a strength.¬† It allows people like me to detect security vulnerabilities, like many other can do, and documents them, or protect against them, so others cannot silently abuse them, without users understanding what’s going on.

XBOX S-Video + SPDIF mod

This mod gives S-Video output, and SPDIF (digital audio) output, plus removes the need for the original audio+video cable

Why:¬† XBOX usually delivers Composite Video output + Stereo output.¬†¬† With an “Advanced” cable, user can enjoy RGB video & optical SPDIF.
I wanted higher video quality then composite video delivers, and my projector (as most projectors) does not support RGB.S-Video is better then Composite, mostly because it uses 2 wires (Luminance & Chrominance) , instead of  just using one wire, as Composite does.

This mod allows XBOX to boot & work just fine without the original audio+video-cable connected.

The original cable is still working after modding this way.

This should not be necessary to say, :¬† This voids your XBOX warranty instantly ūüôā

+The original connector/cable will still work as before.

I skip schematics – here goes the pictures…¬† they say it all:

Finding the signals/connecting to them:

This picture shows the solder-side of the XBOX motherboard, where the video+audio connector is mounted.
RED long wire,  goes to the center of the SPDIF connector.
WHITE wire, is the S-VIDEO Luminance line
GREEN wire, is the S-VIDEO Chrominance line
The thin RED wire that connects three solder-points , connects two sensing-points to GND, When this two points are grounded РXBOX is cheated to believing that the original cable is connected, AND  SPDIF digital audio output is enabled

TRICK:  Usually РI would also need to connect the Y-GND & C-GND lines too.  XBOX is fortunately well build and uses common ground for all I/O lines, and therefore, I will use the ground from the XBOX  chassis instead..

Now , The connectors:

This is the inside of XBOX’s rear shielding plate.,

I drilled some holes, and inserted:
One female RCA connector for the SPDIF
One female S-VIDEO connector
Both connector’s shields are soldered to the XBOX’s chassis-shield (perfect ground source, XBOX motherboard is very well grounded at several points)

Finally , Connecting the connectors:

*1  =  S-Video connector.   There are two more pins beneath the two you see.  These pins are connected to ground.
*2  =  SPDIF, ground connected by soldering shield to the XBOX shield

HINT: You can see I removed the tin-fan-grills that  were between the fan and the plastic fan-grills.  I did it to improve air-flow.

A better alternative :

Using shielded cables might give higher quality – I did not see any difference, but here’s some pictures of this mod with shielded cables…

PainmakerLCD 2

Worlds most advanced paintball marker controller. (back in’97)

New electronics for Brass Eagle’s Rainmaker

-who says the standard Rainmaker must be ugly-grey  Рhere it is in  black(picture taken with flash)

(I do not sell them anymore – sorry)

This is what you get :
-PainmakerLCD board
-Better trigger switch , (much tighter)
-The optocoupler if you want to use the  Revolution-Starter option
-Schematics you might need.
-Shipping to anywhere on Earth

Those were sold for US$ 230.


Some facts :

  • – all electronics are inside the fore-grip , on two dual-sided PCB’s with a “bus” in-between
  • – CPU is a¬† 20Mhz RISC processor , with 8KB Flash EEPROM¬† .
  • – The Source code (ver 1.0) were 3328 lines of pure assembly. (takes 48 A4 pages when printed)
  • – All settings / preferences are saved in EEPROM ,… no battery is needed to keep settings.
  • – All menus / functions are controlled by only three buttons .
  • – Electronic Safety is on when in any configuration menu. or reloading (loader lid open)
  • – It’s powered by one 9V Ni-Mh battery inside the grip , but can also take 12Volts or more.
  • – It have both a high-intensity LED and high-frequency beep (hard to localize the sound , HF sound does not travel as far as lower freq. do) , beeping¬† is¬† used for warnings/alarms/ button-confirmation + +


Features & Menus:

It all starts with Intro …


(Ready For Action: Totally fired 0015 , this round 0000 , LFT(left in loader 188 balls))

(This is the playing screen)

This is how the LCD looks like during a game. There are two independent counters that can be reset when you like , and can be saved to EEPROM and loaded at next game.


Load/Save Configuration , Painmaker LCD loads all previously saved settings at each boot, if you then make any changes they will not be saved until you save them , on the other hand , you can make some changes you are not happy with , and just load the previous  (takes only two button-presses to do that.)


(After 278 balls are fired the last round (since last RND reset), totally 278 this “day” (since last TOT reset) , and there is 13 left in loader) so the LED is lit as a warning (because warning is on (in this case) if there are <=25balls left)

(This is the playing screen)

This is ho

w the LCD looks like during a game


The loader detected that the loader lid is open ,(reloading) the display is showing this , until the loader is closed , safety is on.  , the LED is turned off.


Loader is closed , the result of the above calculation (balls left + balls in a pouch) is 116.  (This is the playing screen)


Reset menu : allows to reset total counter , and/or round counter¬† “-” is left button “+” is right button


Menu : Battery – Shows battery voltage ,+/- 0.01 volt ,( it’s calibrated with a Fluke.)

this is updated so fast ,¬† that voltage changes are “animated” on the LCD (when 46 changes to 45 both “6” and “5” are showing because the 10bit DAC cannot decide the LSB¬†¬†¬† ¬†¬†¬† very cool.


Low Battery Warning Menu : … user can decide when the low-battery warning (audio) should be activated, (the minimum working voltage is different for Ni-Mh , Ni-Cd & Alkaline batteries.¬†¬† (+/- buttons increase/decrease this value , holding down “+” increases value fast , holding down “-” decreases value fast)

a “beep” sounds every idle 2 sec if voltage is low


If the battery is low , It’s also on the main screen…


Temperature :¬† a precalibrated to 0.5¬į C state-of-the-art IC is measuring the temperature , and sending the results serially to the CPU¬† ,¬†¬†¬†¬† It’s not like the “AngelLCD” thermometer¬†¬†¬† ¬†¬†¬† , but a really professional (industrial) thermometer , calibrated to +/- 0,5¬įC¬†.¬†¬†¬†¬†¬† If you live in Norway (like me) and play when it’s about 10¬įC¬†¬†¬†¬† , it might be cool to know how cold it is , as the paint starts breaking really easy at that low temperatures . It might be useful at high temperatures too.

added Fahrenheit degrees , at first I wanted to calculate it , but it’s pretty difficult because of the decimals needed ,¬† , so I use a lookup-table , to save space the table have 60 entries , 1..60 ¬įC¬† , so the Centigrade has higher resolution (0.5deg) and the Fahrenheit temperature is the same for 25¬įC and 25.5¬įC.


Configure menu is where settings like burst-size and loader capacity is set in “setup” part , and burst-on/off , fullauto and other are under “modes”¬† , go to left or right to continue setup from here.

Loader capacity presets the maximum Loader capacity … (+/- buttons increase/decrease this value)

188 is the space in a Revolution + it’s neck.

Pouch capacity must be known, (to add right amount of balls when loading) … (“+”/”-” buttons increase/decrease this value , holding down “+” increases value fast , holding down “-” decreases value fast)

Here is the low ammo warning configuration , it’s now set to warn me when 25 balls are left (“+”/”-” buttons increase/decrease this value , holding down “+” increases fast , holding down “-” decreases fast)


Tournament-Lock    This menu will ONLY appear if the Tournament-Lock is ON  and then NONE of the menus below will show. Causing the last selected configuration being used without any way to change it during game.

This is THE BEST Tournament-Lock feature because :¬† It will let me not only lock-out the coolest features , (like any Tournament-Lock does)¬† , but It allows to keep any settings , and only restrict changes.¬†¬†¬† Like : I’m will play in a Scenario-Game (Command & Conquer) which allows any fire-mode up to 9bps , even fully automatic¬† . So I can choose any mode I like , and still restrict myself from being able too choose 13bps . by selecting Tournament-Lock when rebooting¬† ,¬† , and a battery-change does NOT affect the Lock’s state.

The only way to toggle this selection is to reboot , while holding all 3 menu-buttons (beeping) depressed in about 2 seconds (during the boot & intro sequence) which is  , needless to say , not possible during the game.  (playing with battery & beeping 2 seconds will catch referees attention.) m and the process would need to be undone at end of game.

the display also shows that Tournament-Lock is active during the game , (unless when that space is used to tell important things like Low-Battery) , anyway the first “Tournament Lock is On” can be reproduced.

Dwell Adjust : 1…30 ms in 1ms steps .

¬† no rainmaker can shoot at speeds like 15bps ,because it will not have time enough to feed each ball , only the balls that quickly gets into place.¬†¬† this is because of the low pressure controlled ram needs a minimum of time to cycle the mechanism . and at higher rate-of-fire there is very little time to feed next ball.¬†¬†¬† When this time is too long , time is wasted , precious time that could be used to feed ball… (any default configuration on any controller board¬† waste some time)¬†¬† on the other hand ,¬†¬†¬†¬†¬† When this time is too short , The rainmaker will have a significant blowback , (because it’ll open the “chamber” when there is still very high pressure in the barrel) , of if this time is way-to-short , it will not fire at all , (the ram is reversed before it’s in hammer-release position)

So , this value should be set as low as possible , allowing normal function ,  this will extend the ball-loading-time.   This setting does NOT influence the rate-of-fire in any way, each ms set here is compensated for.

The optimal value of this setting will vary from rainmaker to rainmaker , because the time delay needed is dependent on : low-pressure-spring , ram , and hammer spring.

Also , having the optimal setting will save battery , the 9volt battery works pretty hard when it opens the MAC valve.¬† Because of the way PainmakerLCD is constructed it uses a higher voltage to control the Power-MOS-FET that opens the 6volt valve.¬† This gives a impressive raise-time and very “strict” MAC-valve movement.¬†¬† , (anyway use Ni-Cd rechargeable battery)

To make the adjustment easier to try out , There are 2 Dwell settings that can be programmed , and then toggled.


Configuration of¬† “burst” or “family” mode¬†¬†¬†¬†¬† (“+”/”-” buttons increase/decrease this value , holding down “+” increases fast , holding down “-” decreases fast)


BurstStop = (On/Off) let’s user choose if a burst should be interrupted when trigger released , or not.



AutoBurst = (On/Off) , Similar to AutoRepeat , if on , burst repeats with a brief pause in between (until trigger released) , a three ball burst sounds like “bang-bang-bang….bang-bang-bang….bang-bang-bang….”


Autorepeat :¬† whatever the fire mode is (normal/burst/turbo) , when trigger is held down 250ms (0.25sec) , the Painmaker switches to fully automatic until trigger is released , good for bad situations ¬† (and then returns to the mode it was in before) ,¬† (pressing “+” is “ON” , pressing “-” is “OFF”)


Burst: turns on/off the burst/family mode , which can be set to anything between 2 and 255 balls ¬†¬†¬†¬†¬†¬†¬†¬†¬†¬† (pressing “+” is “ON” , pressing “-” is “OFF”)


Fully-automatic : turns on/off the ammo-wasting mode.¬†¬†¬†¬†¬†¬†¬† (pressing “+” is “ON” , pressing “-” is “OFF”)

Turbo Mode menu : turns on/off the turbo mode.¬†¬†¬†¬†¬†¬†¬† (pressing “+” is “ON” , pressing “-” is “OFF”)


Fire rate , applies to all fire-modes and can be programmed to anything between 6.5 and 15** balls/s in 0.5rounds/s increments¬† (“+”/”-” buttons increase/decrease this value one step each click)) this setting limits the fire rate in ANY selected mode. It applies to all fire modes.

**There is no gravity-loader that will provide more than 13balls/second continuously (more than 4 shots), my tests gave me some “blanks” in between shots.¬† There are many things that will set the¬† maximum fire-rate you can achieve :¬† Loader, Dwell -(shorter is better) ,Low-Pressure system’s pressure (a little higher pressure will move bolt faster) , Bolt , (heavy bolt will move slower) +.

I made the selection go to 15bps in 0.5bps steps to allow everybody experiment and find your own maximum setting , my calculations (of recorded audio form Rainmaker) makes me believe that 15bps is possible with forced feed or a longer vertical feed , (if the balls are “falling”¬† faster into chamber there won’t be blanks) , 10 or 10.5 is the maximum of what my revolution loader can deliver continuously.


Backlit sets the intensity of the backlit when in menu mode , (backlit is always of in game mode) – 0 means off , 255 = max intensity


Those three menu-buttons (“+” ,¬† “Select” , “-“)¬†¬†¬†¬†¬† and the mini-jack connector to the Revolution-Loader


Battery is now inside the grip

… but a higher-capacity battery is recommended for trouble free , long play , go see the “PainmakerLCD Power”¬† page..



(Revolution-Loader mod.)

the button that detects when the lid is open , and the high-intensity-LED that’s used as a warning

button & LED in place , and also the original Revolution-loader electronics.

closed revolution-loader , with the mini-jack connector

difficult to photograph , but it’s the high intensity almost LED blending the camera to tell the ammo is low



  • Q: Is it an ADD-ON or what ?
  • A: It’s a complete replacement of ANY wires/electronics you might find inside your Rainmaker. or any compatible marker)


  • Q: Can you make it fit inside gripframe ?
  • A: ….technically yes , but not using the display I’ve programmed for (it’s too big) , I would also have to order some professional PCB’s made for¬† SMD (SurfaceMountedDevice) components. the size is as it is, because I did built it to be technically perfect , like : the PowerMOSFET controlling the valve is totally isolated from the CPU , using a optocoupler. , all this stuff takes some space u know.¬†¬†¬†¬† , so…. It can fit inside , but will need a smaller display and a new PCB¬† , ….today , only the earlier project , the Painmaker (noLCD) can fit inside .. it has much common functionality , fire-modes/autorepeat¬† , on the other hand , a display inside grip us useless during play (may have little information and take some time too read)¬†¬† , while when using this big LCD you can read it all very quickly by only turning the marker.


  • Q: Is it only for Rainmaker or will it fit any marker.?
  • A: It will work on ANY marker , the trigger input can handle both optical (semiconductor)) and mechanical-switch triggers , and the Valve/Solenoid output is very powerful , and can handle whatever load you need , the PowerMOSFET is driven by a higher voltage than it switches , it means the MOSFET is switching really FAST and powerful (very low internal resistance and low rise-time) NO other controller boards for any paintgun does this , as it requires a higher voltage than the CPU works at and thus a electrical isolation¬†between PowerMOSFET and CPU¬† … The whole thing needs power supply between 7…24Volts.


Painmaker (Rainmaker modification)

Worlds most advanced (back in ’97) paintball-marker controller board without LCD

This is a new microcontroller board with new features , including very useful “Autorepeat” for Brass Eagle’s Rainmaker

Buy it NOW :

This is what you get :
-Painmaker board
-Better trigger switch , (much tighter)
-The optocoupler you need if you want to use the  Revolution-Starter option
-Schematics you might need.
-Shipping to anywhere on Earth

(no longer for sale, and out of stock).


Inside the grip….

The latest version ready for shipping , the two white wires goes to the valve…

The red LED (Light Emitting Diode) goes to the hole where the original circuit’s LED were.

Hardware used :

  • 4Mhz RISC Processor , assembly programmed , (no high level mess inside) .
  • 4Mhz resonator (for stable temperature independent frequency).
  • HEXFET (Power-MOS-FET) from International Rectifier controls valve.
  • Integrated 6 Volts regulator to use 9V battery (NiMh or NiCd rechargeable is nice) ,or any power source up to 30volts
  • (Painmaker can use the 18volt you already have in your Revolution / Evolution loader
  • Quad DIL-Switch to select configurations.
  • The Painmaker is polarity-protected, connecting battery wrong way does not destroy anything.


Features & Options :
  • Fullauto : No description needed , it blows out your paint really fast , at selected fireratio , mostly for people in stressed situations.
  • Burst : Fire preselected amount of balls each time trigger is pressed.
  • BurstStop : when enabled : a burst can be stopped by releasing trigger.
  • Turbo : The original “Turbo Mode”. , shoots when trigger is pressed AND released.
  • Semiautomatic : One ball at a time , lust like any tippman98 or stingray
  • Autorepeat : When trigger is held down more 200ms (0.2 sec.) after a shot been fired in any mode , the Painmaker switches to fully-automatic¬† , until trigger is released , then it returns to it’s previous mode ……..good for bad situations
  • AutoBurst : just as Autorepeat , but repeats selected mode (burst/whatever) each 0.27sec.
  • Dwell Setting¬† : Ability to program true dwell time (the time main-valve are open)¬† , this time is compensated and does NOT influence the ROF (unlike other not-so-cool boards) do.¬†¬†¬† Read “Dwell setting” explanation in FAQ:
  • ROF¬† (Rate Of Fire) : Any ROF you choose , cannot be exceeded by any configuration , it limits all modes ,, you cannot shoot faster than this setting…
  • Tournament-Lock :If all 4 switches are OFF , : the programming mode cannot be entered when booting , Only semi-auto is enabled , and the ROF is set to right below 9bps , however , all user-setting are still “remembered” and the programmed Dwell is used , NPPL rules allow any Dwell setting.
  • Tournament-Ok : If the ROF is 9 or less balls/sec.¬† AND the Fullauto/Burst + +features are switched off , (as NPPL tournament rules says) then the LED will flash quickly 3 times when power is turned on.¬† , This way , referee’s can easily check that any settings you chose is following the rules….
  • Quick-Select : Three of those gold-plated-pins (are dedicated to Quick-Select , user can mount a 2-or 3 position-switch there , the pins are GND (Ground) Fullauto-IN and Burst-IN¬† , Fullauto-In is connected to GND , the Fullauto kicks in , if Burst-IN goes to GND , the Burst is on.¬†¬† This allows user switch between semi , burst , and fullauto as any real gun ¬† nice for scenario-games.¬†¬†¬† Of course Quick-Select are disabled when Tournament-Lock is on. Use if you want it , or just leave them unconnected.
  • Revolution-Starter : A digital output line , that starts “revolution” or “evolution” loader each time a ball is shot. User must mount one single component¬† inside the Revolution-loader , and route 2 wires from Painmaker-board to the loader. very easy operation , well described in the “manual”….¬†¬† the Painmaker is ready for this , the extra component is available for an additional 5 US$.

Programming mode :

Basic programming¬† knowledge , : Programming is done using binary system , “0” means switch off¬†¬†¬†¬† , “1” means switch on , “x”¬† means “don’t care”¬†¬† , you will see there are some “default” ¬†settings at each table , those are not really defaults , but rather “recommended” or “basic” settings , if you skip programming one table , the last value you set it to will be preserved , it will not be set to “default” …

(¬† ! do not let all DIP-switches be “off” when connecting battery , this enables Tournament-Locked mode and you can’t enter programming mode , tournament Locked mode flashes the LED quickly 3 times when you connect power. , let at least one switch to be “on” in order to enter prog.mode)


1.- When connecting battery , hold down trigger about one second  ,then release trigger.

2.- The LED will blink ONE time , to tell you to use table 1:

table 1 (setting 1 (off,off,off,on) is default.

(those settings are OPTIONS , leave all “off” , and you have the semi mode…Any choice can be combined , if you want to turn on autorepeat and turbo , the switches will be “on-off-off-on”)

3.- Now , you are done setting the switches ,  the trigger have two functions in programming mode :  to SKIP to next table (and keep the setting you had before , press trigger , to REPROGRAM this table (using current dip settings) , press and hold trigger about 0.4 second , then the LED will flash quickly 10 times to confirm. (release the trigger when it flashes)  and then , you move to next step:

4.- The LED will blink TWO times , to tell you to use table 2

  table 2 (off,off,off,off) is default.

5.- The LED will blink THREE times , to tell you to use table 3

table 3 (setting 3 is default)

6- When you selected the fire rate , using the same dip-switches as before , Press Trigger (as described in step 3).

7.- The LED will blink THREE times , to tell you to use table 4

table 4 (setting 13 is default)

8.- The dwell should be set to 40ms¬† (on-on-off-on) which will give good functioning rainmaker , then decrease until you get a little blowback. when done , press trigger. (as described in step 3)…

9.- The LED will blink Four times , to tell you to use table 5

table 5   (setting 3 is default)

10.- Now you can configure the size of one burst , (used if burst mode enabled) ,, press trigger when done. , then you are ready to play.

Additional information :¬† No settings are saved in EEPROM until table 4 is done , after that ,the new setting are in-use , and the board in back in “shooting”) mode – no reboot necessary.

All those settings are saved in EEPROM , and will not be lost for over 30 years after battery is disconnected.



  • Q: What do I get ?
  • A:¬† A assembled Painmaker PCB with processor , battery-connector ,and trigger-switch¬† basically everything you need , All you need to do is to connect two wires to the MAC-VALVE.
  • Q: Can the Revolution or Evolution loader-mod damage my loader or the voltage from loader damage my Painmaker) ?
  • A: No , the output to the loader and the loader itself is electrically isolated for 4000 volts. (that’s what the optocoupler does)
  • Q: Will the Revolution or Evolution loader work as usual when the Painmaker board is disconnected ?
  • A:¬† Yes.¬†The loader will work if it does not sense a ball OR when it gets a signal from Painmaker board.
  • Q: What is dwell setting and why would I like to mess with it ?
  • A:¬†at a given fire rate , let’s say 10 bps , each cycle takes 100ms (milliseconds) , there are mainly two big “events” that need to be done during those 100ms , the shooting starts with closing the chamber , the ball is fired (valve opened), ….and the second part : the chamber is opened , to get another ball , so it’s ready for the next shot. ….. Now , by decreasing the dwell (the time the chamber is closed) you will increase the time the chamber is open , and that’s just what you want.¬†¬† The main reason that you cannot shoot continuously 16pbs is that there is no loader that would feed the balls fast enough , that would need to be forced feeding , not gravity based , so no revolution or evolution will be able to provide enough paint.¬† By reducing dwell time to the shortest working time (before you get blowback) , you increase the time chamber is open , and increase the chances a ball have to be loaded , when balls do not have enough time ,(too high ROF, and too little time) you will fire blanks. and very louse paint may break (be chopped) remember 2 things : one.-¬† Rainmaker does not normally chop half-loaded balls due to very cool construction , you can stop the bolt using a finger¬† , not recommended with stingray ,¬†¬†¬† and two : decreasing dwell time to the point where blowback is significant , will NOT help the loading time. Remember the credit-card test.


  • To check/verify if it’s tournament-locked , according to NPPL rules , : check that all 4 DIP-Switches are in OFF position at boot, if they are , then it is locked¬†, put a tape over the hole to “seal them”
  • Locked mode can be verified even more easily :¬† When battery is reconnected the Tournament-OK feature will quickly flash the LED 3 times¬† if the Painmaker is locked .
  • As most other markers , if user is disabled from reaching the switches during game , (the grip rubber is screwed into place or there is tape over switch-hole)¬† ,¬†it’s locked.
  • The Painmaker cannot change from locked mode without¬† modifying the switches AND rebooting (resetting power by disconnecting it, and reconnecting after 1-2 seconds).


Trigger Modification :

The trigger mod have been planned since I started the Painmaker project. The Trigger Modification gives (measuring on the end of a 2 finger trigger) only 3mm movement between released trigger and “trigged” ¬†¬† , this makes quick shooting more accurate and easy , the switch can be found at www.elfa.se it’s part # is :35-677-24¬† , datasheet .¬†¬† the switch life multiple millions of cycles.

Paint Them All – Let Referee Sort Them Out ūüôā