RC Car Update

Last 2 weeks:

I have still been waiting on the well recommended Circuits@Home USB host shield (1); This will be used to communicate with either an Xbox or PS3 controller (I have written a test program for both but need the host shield to see what controller interacts better and more fluidly; many suggest ps3 but we will see). I chose this Host Shield for a couple reasons; first this is the manufacturer (Circuits@Home) recommended by Arduino themselves, they also are the ones behind the library that we plan to use which will interact with our remote controller (according to some; other, third party, shields can work but compatibility with the library is not guaranteed) and also after seeing Arduino’s documentation on shield pin usage (2), this host shield seems the least likely to interfere with pins needed for our Motor/Servo Shield -more on this in a minute;  The library used to interact with the host shield and controller can be found here (3).

After a few emails and still no response from Circuits@Home I began getting a bit anxious and after looking around found a LinkSprite USB Shield at a DIY electronics store (Pleasantview Electronics) in Golden. Unfortunately this shield did not help my progress. First the shield would not behave with my Motor Shield. The lack of good documentation made it so I had to personally examine and decipher what Digital pins were being used. After finding that 3 of the 4 motor shield pins were also used by the Host shield I began the tedious task of modifying the host shield’s pin assignments (on the board itself and in the software). In short this did not turn out successful; I never could get the motor shield completely functional while part of a stacked assembly (either on top or as the middle shield). I still thought however that getting the host shield working without the motor shield would be valuable in that I could now test my controller testing programs (these simply display controller input data to the screen). Again the LinkSprite shield would not behave, I got it working with a usb drive, but it failed to connect with both a PS3 or Xbox controller. While a bit perturbed I moved on.

My plan as of recently was to abandon the use of XBee RF Antenna Modules (4) due to their high price tag (most run from $30 – $75 each and we would need 2 + the appropriate shields), but after some thought I figured that the large investment is worth it because “A” the technology is applicable to many future endeavors and “B” is essential if I plan to expand this project. (Use of a bluetooth dongle has a max range of maybe 50 feet, while some XBee’s claim to reach miles). I bought 2 XBee 802.15.4 modules, and used Digi’s free software (X-CTU) to program the modules to interact. I then ran a sample sketch that used one XBee (connected to my computer) to send serial data to the other  XBee which interpreted the data to turn on and off a LED. While I have yet to get a controller hooked up to the XBee (Still waiting on Hardware), the successful serial communication between the two XBees was a time-consuming and noteworthy accomplishment.

Update – I have received a response from Oleg (owner) at Circuits@Home apologizing for the great delay, apparently they are more or less a one man operation and have been struggling to keep up with orders. Am told order should arrive this week.

1. https://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-2-0-for-arduino

2. http://playground.arduino.cc/Main/ShieldPinUsage

3. https://github.com/felis/USB_Host_Shield_2.0

4. http://www.digi.com/products/xbee-rf-solutions/modules

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