Hello everyone,
i’m trying to make a kind of segway but i’m facing issues with motor noise under heavy load.
This is the setup:
Arduino uno
2x500w motors brushed
Sabertooth driver 2x32A
2x12V 60A batteries

I made this project with a Sabertooth 2x12A at the beginning and 250W motors, it was working but it was a bit undersized for my weight.
I then upgraded to the Sabertooth 2x32A and 500w motors.

Without the chain (so motors are not under loads and are free to rotate) no issue at all, as i put chains and so wheels are engaged after even a small move the MPU6850 gave wrong numbers and arduino freezes…motors goes at 100% power (that is bad).

i tried to short cables and twisted them for i2c and to attach small capacitors between motors wire and from motor wires to ground of chassis.

i tried to have a separate power source for arduino…

no luck.

Any suggest will be much much appreciate

bets regards

Schema_GASWay V2.pdf (247 KB)

have you tried 0.1uf caps on the arduino power supply lines to ground,also on all the arduino sensor inputs to ground?

Firstly you need to sort out the grounding properly. Use a star-ground configuration such that there is only one ground connection between Arduino and motor driver.

This means separate supply for Arduino if at all possible, rather than using the 5V from the noisy motor driver.

All sensor cables need to be routed well away from high current wiring, all high-current wiring needs to be twisted pair or better still shielded twisted pair. There will be lots of magnetic noise near the motors and the high current wiring, separate stuff out into separate wiring harnesses, one for high current, one for signals.

One really bad thing to avoid is grounding sensors to the chassis. Sensors should be grounded (via a shielded cable ideally) to the Arduino ground, and to nothing else. A chassis will act as a big loop antenna, unless you need to connect it, isolate it from your circuitry. With a motor the motor case is strongly coupled to the windings capacitively, so will need grounding to the power circuit ground to reduce the voltage noise on it (motor cases inevitably also connect to the chassis electrically - this may be the only unavoidable ground loop)

Given the size of the system you may have issues spacing things away from the motors, in which case the more you shield stuff the better - individual diecast boxes for each bit of electronics can help, so long as they are not electrically connected to the chassis (which would create ground loops).

Adding opto-isolation between control side and power side is also a useful strategy, but won't help if the interference route is through the metalwork/chassis or from shared power supply.