The example below is only one way how to set up the Relay Module.

In this examples we have connected a PICO to the BEVRLink Manager PICO V2 with BEVRLink 4 Channel Relay and 4 manual test buttons 12V. With this relay module board you need the BEVRLink Power Supply 12V 2A. 

Optional for a safe setup we recommend to use case for both the manager and relay boards: BEVRLink Cases

Set up CircuitPython

1. Download latest CircuitPython Firmware
2. Hold BOOTSEL while plugging the PICO in to your PC
3. A USB Drive called RPI-RP2 should appear on your computer
4. Drag and drop the downloaded UF2 to the Drive
5. The board will automatically flash it self and reboot removing the drive
6. You will get a new USB Drive attached called CIRCUITPY that will hold your code and files

Code

1. Write the code in a code.py file

import time
import board
import busio

# Initialize the I2C bus:
i2cbus = busio.I2C(scl=board.GP1, sda=board.GP0)

i2caddress_Relay_1 = 0x38 # Address of relay card 1  
i2caddress_Relay_2 = 0x39 # Address of relay expansion card 

# Registers
INREG = 0x00 # Input read register
OUTREG = 0x01 # Output write register    
IOCONF = 0x03 # Configure IO as Input or Output register

# Take over the i2cbus
while not i2cbus.try_lock():
    pass

# Config 4 first pins as outputs and 4 last as inputs
i2cbus.writeto(i2caddress_Relay_1, bytes([IOCONF, 0xF0]))
i2cbus.writeto(i2caddress_Relay_2, bytes([IOCONF, 0xF0]))

# Define holder for buttons
input1 = bytearray(1)
input2 = bytearray(1)

while (True): # Loop
    # Read the inputs and copy it to the output
    i2cbus.writeto_then_readfrom(i2caddress_Relay_1, bytes([INREG]), input1) 
    i2cbus.writeto_then_readfrom(i2caddress_Relay_2, bytes([INREG]), input2) 
    
    value1 = ~(int.from_bytes(input1, 'big') >> 4) & 0x0F
    i2cbus.writeto(i2caddress_Relay_1, bytes([OUTREG, value1]))
    value2 = ~(int.from_bytes(input2, 'big') >> 4) & 0x0F
    i2cbus.writeto(i2caddress_Relay_2, bytes([OUTREG, value2]))

Copy the code file code.py to the USB drive CIRCUITPY.

The code should autorun as soon as it saved on the drive, otherwise open a serial connection to the Pico shell and check for errors