ESP32 F9P IO board

This PCB is a versatile IO plattform that provides computing power (ESP32) and IO interfaces to build GPS/RTK applications.

Hardware Overview

• Power supply:
  • Input 9V-28V (labeld 12V on the board), external connection on J4.
  • Protected against wrong polarity (Diode D7 parallel to the relay K1)
  • Reduced inrush current (resistors R15/16 in serie with the starting diode D7 before the relay K1 closes and shortens the path).
  • V78E05-1000 (step down converter) PS1 generates 5V
  • AZ1117-3.3 LDO U2 generates 3V from the 5V supply.
  • 12A (slow) fuse soldered on the board. Recommended to use a 10A external fuse.
• ESP32-WROOM-32 U1 for computing-power, wifi, Bluetooth
• Arduino headers for the simpleRTK2B-F9P (uart 1 of the F9P connected)
• Serial interfaces
  • one uart (IO13/14) on the Arduino headers for the F9P
  • one uart (IO0/2) next to the arduino headers on two pins (J2) for the new simpleRTK2Blight. Since the two pins have a special meaning during boot, pulling TX to GND during startup results in the ESP going into programming mode.
  • one uart (IO15/16) for RS232 on the D-Sub connector J16
  • one uart (IO1/3) on the USB-Uart converter (J14) - Also supports programming with "RTS/DTR"
• I2C (IO32/33)
  • I2C with 3.3V logic level (J8 pin header, J13,17 qwiic connector)
  • I2C with 5V logic level (J7 pin header)
  • internal used adresses:
    • 0x1C - Magnetometer part of the LSM9DS1 (U12)
    • 0x43 - FXL6408 port extender (IC 1)
    • 0x48 - ADS1115 (U4)
    • 0x6A - Accelerometer part of the LSM9DS1 (U12)
• CAN bus
  • Tranceiver (U2) + ESP32 integrated controler (TX IO5, RX IO35)
  • Termination resistor and sending messages can/must both be enabled with a jumper on J12
  • external connection J18
• Ethernet:
  • internal MAC, connected to LAN8720A on IO17,18,19,21,22,23,25,26,27
    • IO17 Clock
    • IO18 MDIO
    • IO23 MDC
  • PHY-Reset controlled with FXL6408-GPI01
  • ETH-Address of the LAN8720: 0
• IMU: 9 Axis, LSM9DS1 (U12). Magnetometer needs iron correction to be usable.
• Outputs
  • One H-bridge/motordriver with two VNH7070AS (U3/5), (PWM IO4, FXL6408-GPIO6/7 direction). External connected on J4
  • One H-bridge/motordriver with one VNH7070AS (U9), (PWM IO12, FXL6408-GPI04/5 direction), external connected on J3
  • One Relay (K2) controlled on FXL6408-GPI03, external connected on J3
  • One status LED (D2) controlled on FXL6408-GPI02
• Inputs
  • Three 15V tolerant (analog) inputs IO34, SENSOR_VN/36, SENSOR_VP/39, external connected on J1
  • Three 5V tolerant (analog) inputs on the ADS1115, first two cann be used to measure differential. Number four is hardwired to VCC/5V. External connected on J5
  • One Button (e.g. for entering configuration mode), on FXL6408-GPI00
• Connectors:
  • J1 - 6 pin PTSM header. 15V tolerant inputs and 12V for easy cabeling if used as switch
  • J2 - 2 Pin Uart
  • J3 - 7 pin PTSM header. Outputs of second H-bridge, two times ground (for using as two half bridges) and the three pins for the relay (comm, no, nc)
  • J4 - 4 pin CCA header. Power input and output of the first motor driver/h-bridge
  • J5 - 5 pin PTSM header. Three ADS1115 inputs, 5V and GND for easy cabeling (e.g. linear potentiometer)
  • J7 - 4 pin header. I2C 5V logic level + GND and 5V
  • J8 - 4 pin header. I2C 3V3 logic level + GND and 3V3
  • J9, J10, J11 - 8 pin header. Socket for the simpleRTK2B F9P
  • J12 - 2x2 horizontal pin header. Used for jumpers to enable CAN termination and/or CAN TX
  • J13, J17 - qwiic connector. I2C 3V3
  • J14 - micro USB connector. Can power 5V and 3V3 part of the PCB. Electricaly not isolated! Used for programming the ESP32
  • J15 - RJ45 ethernet connector
  • J16 - D-Sub connector (male). RS232
  • J18 - 2 pin PTSM header. CAN bus