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.



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I tried charging at a voltage of 18 Volts, and the current that flows to the batteries did indeed increase a lot.
At a voltage of 16V the current was 0.3-0.4 Amps, now with 18V the current is 2.5-2.7 Amps.
But the disadvantage is that it indeed gets extremely hot, could it be that it melt?
Because the screw of the charge circuit is made out of plastic and it has a plastic plate below it for isolation.
Could the plastic melt?

No the Nylon screw and insulating washer will not melt. The washer is Mica, not plastic. The electronic components can handle about 150°C before the magic smoke comes out. The nylon will not begin to melt until about 190°C. The Mica will handle up to 500°C before it starts to destabilize.

I'm happy how it now is.
Therefore I'm really thankful for your help.
thanks again. :D

I'm charging the controller with laptop power supply. 19.4 Volt at 3.8 Amp. The heatsink is hot, but its tolerable.

Ideally the current should only be about 2A so I am a bit worried when you say it's 3.8A. I think you might be pushing it a bit and will need to be very careful about adjusting the software to prevent over charging.

It might be a good idea for you to monitor the voltage / temp of the battery and reduce the timeout period if required.

Yes, I'm pushing it. Because I do not have lower Amp power supply at hand. I always monitored the charging, at least until my 2 Amp transformator arrive.

It is not the amperage of the power supply that is the problem. The Amperage rating is just the maximum the power supply it capable of.

The problem is your voltage is too high! Don't go higher than 18V!

Pardon for my English. I'm new user here, bear with me please :)

I just bought Wild Thumper Robot Controller (mounted at 6WD WT). The controller is powered using 12v 4A SLA battery, I have one of these laying around. I belive this is a motorbike battery. I'm using sample file from "Wild_Thumper_Controller.zip" posted above. I have a few question I'd like to ask, if you don't mind.

1. What kind of value should I put in "BATTERY CHARGER SETTINGS" section of constant.h? Especially "batvolt" and "lowvolt". I've read somewhere that the default value is for 7.2v battery. How about 12v 4A SLA?

2. In "H BRIDGE SETTINGS" section of constant.h, there are "Leftmaxamps 800" and "Rightmaxamps 800". I believe this is not 800 Amps, how to get the real Amp out of this numbers? Enlighten me with the calculation if possible, please.

3. What kind of charger should I use with this battery connected to WT Robot Controller? What is the Max Voltage & Amps can I connect to the charger port?

4. The GND + VCC port just beside VBAT + GND, is that 5v output? I believe I've just damaged my 7.4v 1,3A LiPo because I just connect it there while the SLA battery also connected. My bad, I thought the VBAT is just for powering motors and the VCC just for powering the WT Robot Controller. Poor me. The LiPo now is... err how do you put it in English.. fat than before? Any idea what should I do with the LiPo?

Looking forward for your guidance. Thank you very much for your time.

  1. Please read the manual.
  2. Please read the manual.
  3. Please read the manual.
  4. Please read the manual. Vcc is always the logic voltage. If you connected your LiPo here then the controller is dead as well as your LiPo.

I understand that English is not your first language but Google and Bing both have free translation software. I know from experience. I live in China and I do not speak Chinese.

P.S. the manual is attached at the top of this page and is also available from most online resellers as well as my online product support page. Very easy to find with search engines.


Sorry that you're in a bad mood :/


At the beginning of my project, I had read the manual over 5 times.
But now when I have the charge problem, and I read the manual again I see there is a trickle charge mode.
Which explains a lot.
But when the charge mode is off and it goes (like the manual says) to trickle mode, the voltage of the batteries drops.
It's like it stops charging, and using the power of the battery to stay on :s

Is that normal?

Can it be that the trickle mode isn't written in the program but automatically build in the charging circuit? because I can't find anything about that.

thanks for helping