A project log for RoDog

3D printed quadruped robot

Wissam TedrosWissam Tedros 06/14/2021 at 22:560 Comments

I finally Got time to assemble my PCB for the robot, 4 layers, controlled by an STM32f405RGT6,

it features:

  1. 12 PWM outputs for controlling RC servo motion
  2. 12 ADC from the internal potentiometer inside the servos
  3. 12 Shunt resistors of 0.1ohms, for current feedback, this signal is then amplified with a non-inverting op-amp circuit to a good readable range, 0~2.7V, an AD7490 handles the reading and is connected to the MCU by an SPI bus
  4. 9DOF(accelerometer , gyroscope , magnetometer) inertial measurement unit MPU9250 connected to the MCU by an I2c bus
  5.  small FPC connectors(for future plans), I have a plan to make a small 360 scanner, so one of them has an output from a small H-bridge to drive a small hard disk motor with some GPIOs
  6. BQ5887 for 2S Li-ion/Li-Po batteries charging and balancing, to charge the robot from the USB port
  7. USB-Hub for STM32 output and cp2102 USB to UART bridge to program the ESP32-camera 
  8. 4mb external flash memory
  9. additional UART/I2c breakouts and an optional port for a small OLED display
  10. USB B-micro for charging/ and differential pair connected to the MCU
  11. SWD interface for the STM32 

I have turned on the board, computer sees it, and the ST-LINK recognizes it, we're looking Good!