update electronics + car

[Armand du Parc Locmaria]

Mechanical setup

• Last time we used a Tamiya TT-01 chassis which is super great I love it. However, a few time when taking sharp turns the car almost rolled over. For this iteration, we switched to a Kyosho Fazer mk2 chassis which is more modern, wider and closer to the ground. I think it should be better.
• However, When driving the car manually, I feel like it doesn't accelerate as fast as the previous one. Change the pinion gear from 30T to 37T. This will reduce the torque, but increase the speed. I think we don't need that much torque. Let's try and see. If we have time we could also gather data, see how much current the motor draws, how much time to cross X meters, motor rpms etc... very low priority
  • that said, the ESC mid point is set for the PWM module, should try max throttle using this, maybe its more?
• #3
  • Since this is a new chassis, we need to design a new board to hold the electronics. include the cad in this repo.

Electronics:

• Decide if we want to power the jetson nano using the car battery + BEC. or an external USB battery?
  • last time we tried BEC + lipo, we only got like 2 hours of autonomy and then the jetson nano crashed.
  • using an external battery adds weight, easily half a kilo. but it allows to have the two power sources separated.
  • using one source, if the car draws too much power maybe it won't leave enough for the jetson and cause it to crash?
  • currently leaning towards using an external usb battery for the above reasons
• decide if we want to order components for redundancy
  • sometimes (very rarely) the ESC stop working and we can't use the motor. I don't know if its a motor issue, a cable issue or an ESC issue
    • I modified the cable to snoop on the signal but that looks alright to me
    • got the ESC second hand so don't know if its in good shape? doesn't appear damaged though
    • the motor is new? I did solder the cables like a caveman using the max temp of my iron (400 celsius) but i feel this should be fine
  • so, new ESC maybe?
  • maybe a second lipo battery? I don't store the current one at the right voltage so it could be slightly damaged. It could also be good to a have a second one to rotate during vivatech
• Replace ESC
  • order new ESC + cable
  • replace the old one
• solder and calibrate new mpu9250
  • I soldered the last one badly and I think this is why it doesn't work anymore?
  • I also didn't you could and SHOULD calibrate it
• swap the arduino nano every for a xiao samd21
  • the nano every has a micro usb port absolute stone age energy its going to break for sure
  • xiao samd21 has a nice usb C cable but it's 3.3v so I need to check if it will work with the optocoupler
• get a global shutter camera just in case we go 2 FAST