Using the AdaFruit drive motor shield with the Arduino: wheels on the bus go....

Lots of parts arrived this week. The first part was the AdaFruit drive motor shield. I picked this shield as it has the ability to drive four DC motors. Most other shields I looked at only supported two motors. The second part was the 4WD dfrobot kit. I choose this kit as it has plenty of room for sensors on the top, a power supply and wheel encoders. I was specifically interested in the wheel encoders so I can grab information about how far the robot has moved (or think it has moved). That information can feed into the filter estimate of robot localization over time. The parts list for this experiment was:

1. Arduino Uno R3
2. Jumper wires
3. http://www.dfrobot.com/ (although I am just using the motors for this one)
4. https://www.adafruit.com/products/81

The first step was to put together the motor drive shield. This was fairly straight forward as AdaFruit put together a comprehensive installation guide. It took about an hour to solder everything together. I then hooked up the shield and was able to run a sample test to have the motor run forward and backward repeatedly. One step I forgot at first was to use the jumper on the power to use the 9 volt external power supply from the Arduino board. This will not be needed when I switch to the battery pack on the robot. As is pointed out several times throughout the AdaFruit guides, make sure that the LED light is on if you want to get the motors to run.

Here are a few pictures of the initial set of parts and the shield once it was all assembled:

The code for making the motor run forward and back is located in my github folder at:

https://github.com/mark-r-stevens/Ardadv/tree/master/device/actuators/motor/test

Next up, I will start on wiring up the other motors and assembling the dfrobot kit. I also decided that I needed to wirelessly control the robot so I ordered an xbee board so I could send it commands remotely. I may work on that next and then switch over to assembly (plus there is the whole issue of figuring out the encoders).