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Wild Thumper Robot Controller


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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!

Features:
  - 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 recently purchased a Dagu Wild Thumper (6 wheel) and a Wild Thumper Controller, but am experiencing some problems. Steeing in one direction (setup is RC controlled) from the radio controller causes wheels on one side to proportunally increase in speed. Switching direction causes same 3 wheels to proportunally increase in speed in the opposite direction. However, the radio throttle has no effect. I have replaced the link between the RC receiver with servos (to ensure that D0/D1 is receiving the proper signal from the radio controller), and everything works as expected (D0 is getting a throttle signal from the radio and D1 is getting a steering signal from the radio).

To ensure that the correct code is loaded on the virgin controller, I would like to reload it through the Arduino application (I have played with it and a couple Mega 2560 boards in the past). I downloaded the controllers 'virgin' code, but have a few questions before I jump in:

1) What board do I select from the arduino app to download to the thumper controller ?

2) I've never needed an external battery to load the Mega2560 boards (power over USB), but I assume that I WILL need to connect the battery before connecting the USB cable to download to the thumper ... correct ?

Thanks for any assistance.

OK ...

I received my replacement Wild Thumper controller module, and this one seems to have more problems than the last one. This time, only applying power to the controller lights LED2, but there is only a brief flash on LED5 on power connection and then darkness (I am using a 5500 mAh LiPo pack showing 7.42v). The lastest version of the software has been loaded, not that makes any difference. If I can't even get a power indication, there is no point in moving the I/O points around to try to get things working.

At this point I think I would rather look for another drive solution for my Wild Thumper 6WD Chassis. I have a secondary (independent) MEGA2560 that currently handles sensor processing, twin servo camera mount, and some communication, and have a few lines free to handle whatever driver I settle on.

If anyone out there has the Thumper 4 or 6 WD chassis, I would appreciate knowing what you are using to drive it. I'm currently looking at getting a couple of Parallax 25A motor controllers, so if anyone has an opinion about them, I would appreciate hearing it.

 

If you can't get a power light then you must be doing something wrong. In that case changing to different motor drivers won't help.

These controllers are all tested in the factory before shipping and your the only one with this problem. Please post clear, well lit, photos of your setup so we can check you have wired it correctly.

In particular I need a clear picture of the entire controller so I can clearly see where the wires are connected and how thick they are. Show me a photo of your power switch, it should be rated for 25A or higher.

Make sure you have not replaced the nylon screws for metal as this will short out the controller.

If you have servos or other sensors plugged in then make sure you have their ground wire to the outside of the PCB.

Do not try to power the controller from the recharge socket. You must power it from the battery connected to the battery input terminals.

Do not connect the battery to the +5V out terminals or you will kill the controller.

Thanks for the reply Oddbot, but electronics have been a hobby of mine since grade school, and I have been a C programmer for 25+ years. However, I have only been playing with the Arduino processor for several months now. My last robot was the Lynxmotion CHR-3 Hexopod (my 3rd robot), and although considerably more complex than the Dagu drive chassis and controller, it was very simple to both build, program and use (but really needed the upgraded servos).

I admit that a bit of my frustration is that I purchased this controller expecting a turn-key drive system solution. I'm currently more interested in the sensor and 'intelligence' processing side, and so was looking for something that I could just plug a RC receiver into and have an instant RC mobile platform.I guess I didn't expect the problems I ran into.

You say that I am the only one having issues, but looking though other posts here this isn't the case. The docs shipped with the controller don't mention that you will need to change the code to relocate D0 or the controller probably won't work as expected and for that matter, you won't even be able to upload the code unless you disconnect the RC receiver connections (D0 and D1). I found all of that here.

I don't doubt that the controllers are tested and work properly when leaving the factory, but even you in an earlier post asked me to download the latest Arduino code just to make sure that the code on the board was the latest version. Again, I'm not saying the controllers are inheriently faulty, but you have to admit that the instructions that come with the controller could be updated to include some of these 'gotchas', and maybe make the experience a bit easier.

WIth regards to your questions, the last controller was directly connected to the LiPo pack (tamiya connector), and connected to the +Battery and -Battery terminals (according to the diagram included), not to +5 power. The motors were connected to their respective on-board connectors, but nothing else when I connected the LiPo pack. As I mentioned, LED5 flashed ... twice (very short flashes if I remember correctly), but then went dark, but LED2 stayed lit. Disconnecting and reconnecting repeated the same behaviour (nothing was hot, or even warm while the power was connected). Again all connection were done according to the diagram ... and no where else. Before doing any of this I did mount the controller with the standoff spacers to the chassis, but with NYLON standoffs, not the brass ones that came with it. Looking at the board the insets looked isolated from the circuitry, but I didn't want to chance it.

At any rate, again, thanks for your replies to my madness. I know people that don't know what end of a soldering iron to hold, so I don't envy the questions you must get, but I only followed the instructions that were available ... I don't randomly connected wires to see if I can start a fire ...

For my next attemp at getting the platform moving, I think it will try something a bit simplier, and build the code for it from the ground up. That way I will know that if something doesn't work as I expect, it will be my fault, hopefully get some advice from here, and go from there ...

 

Wow ... scratch that last post (read thy PDF) ...

OK ... tried 3 times to upload the thumper controller code. Each time I waited +5 minutes for it to complete (yes I know that it should only take a few seconds). The progress bar at the bottom of the Arduino interface goes to 90% almost instantly, but goes no further. I'm running Arduino v1.0.1

Anyone with any ideas what I can try before I return it ?  I checked my environment by making a change to one of my Mega2560 projects, and had no problem uploading the program to the Mega2560 board.

 

Use version 0022 of Arduino. The new Arduino software is not 100% backward compatible.

I would note that I'm currently using Arduino 1.0.1 and have not had any problems after making the changes I noted in my other comment. Just  something that could be looked into.

I'm assuming you're trying to program the board with your receiver or whatever controller plugged into D0 and/or D1. If you are just unplug the device and reprogram. The problem is that the D0/D1 pins are also the Tx/Rx pins used for serial communications to the board. I ended up modifying the code to have my inputs be where the servo outputs are on the other set of pins to fix and avoid this problem in the future.

Hello,

Is it possible to order extra springs (perhaps 2 springs per motor pair?) or stiffer springs for the 6WD wildthumper? I am having it carry a heavy camera and the current springs can't handle the weight.

thanks, Marcel