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Electronics

Electronics consist of a system of two boards. The first is a power regulation board, which divides the 7.4V into three lines, a 6v for the motors, a 5v for the esp32, and a 3.3v for sensors. The second is a sensor board, which houses all the active components. A TCA9548A acts as an 8-channel I²C multiplexer, allowing the use of 7 VL53L0X which is a time-of-flight laser sensor for proximity and distance measurement. There is also a BNO055 which is a 9-degrees-of-freedom IMU that provides orientation data via accelerometer, gyroscope, and magnetometer; a VL53L0X, and a TCS color sensor for RGB light detection.

Components:

  • Esp32 devkit v1
  • Raspberry pi 5
  • Adafruit VL53L0X
  • Multiplexor TCA9548A
  • Driver tb6612fng
  • Limit switch
  • Adafruit BNO055
  • Servomotor
  • mini560
  • Pololu motors 6v
  • LED strip

Pcb 1

Pcb 2

Failures

There were two boards made, the first one didn´t worked because of some tracks of the board had estrange angles which made it have a lot of noise. And the BNO went to a multiplexer channel, which it can't happen according to the datasheet. The second one had a LED on a strapping pin that made the esp32 reset.

Areas of improvement:

  • Change the microcontroller to another that has more pins or add a GPIO expander.
  • Check there is not a component on the strapping pins.
  • Try to make things smd to have more space.
  • Put the VLX mounted on the board.
  • Try to make the board as small and simple as possible.

Recommendations:

  • Ask for help and ensure the board is checked as many times as possible.
  • Check that you have spare parts for everything.
  • Make a calendar and try to follow it as much as possible.
  • Communicate with all your team members so you are on the same page.