Ever since I laid eyes on the RHex robot made by Boston Dynamics, I had made up my mind to attempt to build one of my own. My version has 4 Whegs (A hybrid of a wheel and a leg). I would need 4 quadrature wheel encoders for this project. Since neither my Arduino Uno nor my Pro Mini would be able to handle 4 encoders, I decided to upgrade to the STM32 series of micro-controllers. This is my first project with these chips and I’m excited to learn about a new type of architecture in the for of ARM chips.
Here is a photo of a 4 legged RHex fromthe Boston Dynamics webpage for the robot:
I chose the STM32F103C8T6 since it was more than upto the task of handling the encoders, but also had a small form factor and was very cheap ($2 on Aliexpress!!). The STM32 works on 3.3v.
Note that you would also need either an ST-Link V2 programmer or a USB to Serial converter in order to upload the code.
Currently I have managed to control speed and direction of the 4 motors and have made the chassis for the project. For the Whegs I decided to try using Polymorph in order to mold them. I’m currently waiting for the Polymorph and encoders to arrive. In case the polymorph does not hold up, I will then shift to PVC pipe for the Whegs.
Here are some pictures of the build so far :
More updates to come soon…………