MR2 project has finished as a big disappointment and a fail. I was expecting that the servos used will run much faster when powering them from 12V. The robot is moving too slow, even slower than MR1. Also, I decided to quit having 4 wheels because I could not manage co-planarity problem (1 or 2 wheels were not touching the floor). I will try again the 4 wheels design on a future robot.

At a certain point I thought to quit finalizing this robot but I decided to go until the end, even if I was foreseeing the failure.

Nevertheless, there are still a few good points with this project: I played with Sharp sensors, with servo (finally I removed the electronics, but in the beginning I used them as servos) and I managed to build the chassis frame a little bit better than on MR1.

 

Specifications

Name MR2
Size 98mm x 98mm x 55mm (length x width x height)
Weight ~280g
Power supply 3S1 LiPo battery
Microcontroller PIC18F26K22 - I/SP @ 32MHz, 5V
Motors 2 x SG5010 BB Standard Servo hacked for continuous rotation + electronics removed
Motor driver SN754410NE 2 pieces in parallel
Wheels custom wheels 43mm diameter
Tires custom tires
Opponent detection sensors

2 x Sharp GP2D12

2 x SHARP GP2y0d340

Margin detection sensors 2 x RPR-220 ROHM
Pushing strength tested on a 1500g water bottle
Communication with PC UART serial communication @9600baud
Operating modes

remote controlled mode
test mode
calibration mode

sumo mode

Microcontroller software The software is written in C language for Hi-Tech PICC compiler

You can download it from here.

Electronics Download it here.

 

Pitcures and videos:

Upside view
Downside view
Rear side view
Front side view
Right side view
Left side view
Together with MR1
MR2 versus toys
MR2 versus water bottle

 

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