Customized XRP robot

Completed the work on the display add-on board - hardware, software, documentation. 

All details are here: 
https://xrpdisplay.readthedocs.io/

Added new wheel, using pololu's silicone tires. You can find the files on printables: https://www.printables.com/model/1275321-wheel-for-xrp-robot-pololu-tires

Created new, smaller chassis, using two 18650 LiIon batteries:
https://a360.co/43SxnfM

Here is the comparison with the stock chassis: