Let's Make Robots!

Wild Thumper Robot Controller

Wild_Thumper_Controller_Instructions.pdf1.23 MB
Wild_Thumper_Controller.zip4.51 KB
Wild_Thumper_Diagnostic.zip2.51 KB
Vendor's Description: 

Wild Thumper  Robot Controller

After creating the Wild Thumper robot chassis I wanted to make a suitable motor controller for it as stall current can be as high as 33A if all 6 motors stall together. As the Wild Thumper chassis's were also ideal platforms for our robot arms I wanted more than just a dual "H" bridge, I wanted servo outputs and a power supply capable of driving some heavy duty servos. Then I thought, hmm.. a battery charger would be handy. The end result is an Arduino compatible controller on steroids!

  - Dual 15A continuous FET "H" bridge with individual fuse protection
  - Current sensing and blown fuse detection for each motor
  - Electronic braking for those high speed robots
  - 7 digital I/O pins terminated in 3 pin male headers with power allowing servos to plug directly onto the board.
  - 5 analog inputs terminated with 3 pin male headers with +5V and Gnd for sensors.
  - 5A LDO regulator to supply power for logic, sensors and servos.
  - 2A current regulator for charging NiCd, NiMh and SLA batteries.
  - Battery voltage monitored by processor. Charger controlled via processor. Allows robot to charge its own batteries.
  - Communication via USB, TTL serial and I2C. Can also accept RC and analog inputs.
  - ATmega 168 processor with 16K flash memory. Programmable via USB or ISP.
  - Comes preloaded with the Arduino bootloader and sample software.

Although designed to work from 6.5V - 12V the controller can be used at voltages as high as 20V if the 5V regulator is not heavily loaded. A CPU fan should be mounted on the heatsink with voltages of 12V or more.

NOTE: The original sample code was written in version 0018 of the Arduino IDE. Newer versioned included definitions of analog pins that prevented the code from compiling. The sample code listed here has been corrected to work with Arduino 0022.

For those advanced users who want to change the PWM frequency, beware! Frequencies above 24KHz will damge the controller.

Here's a something you might want to try.



Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

I did begin to answer your questions but since this product is about 4 years old I had to read the manual. I found all your answers in the manual.

Yes it is normal for the battery voltage to drop when the charger goes to trickle charge or is disconnected. That is because the charging circuit needs to supply more voltage to pump more current into your battery. The higher voltage you saw was from the charging circuit, not the battery.

The trickle charge is only about 50mA. It's only enough to keep the battery from self discharging after being charged. If you accidentally leave the robot on the charger all weekend it will not do any damage.


I've tested the trickle charging, but the batteries is still discharging.

That's because the trickle charge only provides 5.6V to the battery and my battery is 12V.


Also, the charge circuit stops too soon, and so aren't the batteries fully charged. 

Because I can only ride my vericle around 3 minutes, and than it goes to charge mode.

I changed the chargetimeout to an hour so it won't be able to fall out that fast.


The battery has a voltage of 12V and 4.5Ah. So it could normaly at least go for a half hour.

thanks for helping.

At one point there I confused you with SepedaTua who has destroyed his controller by connecting his LiPo to the 5V output of the controller because he did not read the manual.

If your battery is still discharging then you must have some load that is using power or else you forgot to turn on the power suppy you are charging from. Have you modified the code at all?

Please post photos showing how you have wired the controller.

I reply to this because I have the same charge problem as SepedaTua.

And he is also using a 12V battery with a current of 4Ah.


But I didn't destroy my arduino bord with a LiPo battery :D 


I guess that the battery is discharging because it's suppling the Wild Thumper board.


I've uploaded the progam and my scheme to dropbox.

Could you please check it?




Sorry if it's in dutch.




I've re-read your earlier statements. I would suggest trying a higher voltage charger first. A 12V lead acid battery will charge up to about 14V. I think you need an 18-20V power suppy to charge your battery.

So should I put in my program as batvolt the value for a 14V battery?
I normally charge at a voltage of 16V.
But I will try charging at a voltage of 17 V.
If I charge at 18V, the Wild Thumper charging circuit will get extremely hot.
So I don't know if it's a good idea to charge above that voltage, but I will also try charging on a voltage of 18V.
thank you very much

No, unless you are modifying the software then batvolt is the nominal voltage, not the max voltage.

Yes, the charging circuit will get hot enough to burn your hand and after about 10min the heatsink will also get a bit hot. That's normal. If it was not getting very hot before then that was the problem.

Thank you very much.
I will try charging at a higher voltage on tuesday (that's when I'm back in school).
And I will inform you, if its works or not. :D

1 through 3 OddBot would be best to answer not I.

For 2, Leftmaxamps 800 and Rightmaxamps 800 are the values returned by the arduino analogInputs which are normally 0-1023. The manual may be able to elaborate on the significance of the values.

But 4. A buldged LiPo should be safely disposed of according to the manufacturers recommendations and local law. It is just a fire hazard to carry on using it.


I'm also using a Wild Thumper in my project. :D
And so I can give you some answers to you're questions.

But I have also a problem with my batteries. Because the charge circuit jumps too soon off.
I use 10 batteries of 1.2V in series, so they become 1 battery of 12V and 4.5Ah.
I'm able to fix it by setting the chargetimeout higher. So it doesn't switch off that fast.
But thats not the correct way to fix the problem, so I'm still working on that.

The settings I use is;

batvolt            804               (1V is 67, 12*67=804)
lowvolt            469
chargetimeout   3000000    ( the charge circuit falls after 50minutes out)

I don't know that this is right but I think that the 800 stands for 16Amps.
It depends if you're VR1  and VR2 is correctly calibrated.
But normaly you can find that out how much Amp the 800 is by doing: 800*20=16000=16Amps.

For charging please check this website. https://sites.google.com/site/daguproducts/home/tutorials/understanding-wild-thumper
I use a charger of 16V and 4Amps. Make sure that you're charger is more than 2 amps and 3-6V higher than the voltage of the battery being charged.

And yes the GND and VCC is a 5 V output that can deliver a current of 5Amp . So I think you're lipo battery is broken. :/

sorry for my bad english :s

for more information check out my project :