Raspberry Pi RPi Zero Relay User Guide

Overview

Industrial 6-Channel Relay Module For Raspberry Pi Zero, RS485/CAN Bus, Power Supply Isolation, Photocoupler Isolation

Features

  • RS485 half-duplex communication: using SP3485, UART control, auto RX/TX switch
  • CAN half-duplex communication: using MCP2515 + SN65HVD230 solution, SPI control
  • Onboard unibody power supply isolation, provides stable isolated voltage, needs no extra power supply for the isolated terminal
  • Onboard photocoupler isolation, prevent interference from external high-voltage circuit connected to the relay
  • Onboard TVS (Transient Voltage Suppressor), effectively suppress surge voltage and transient spike voltage in the circuit, lightningproof & anti-electrostatic
  • Onboard resettable fuses and protection diodes, ensuring current/voltage stable output, preventing over current/voltage, better shock-resistance performance
  • High quality relay, contact rating: ≤10A 250V AC or ≤10A 30V DC
  • ABS protection enclosure with rail-mount support, easy to install, safe to use

Specifications

  • Operating voltage: 7V~36V (industrial input voltage compatible)
  • Relay channel: 6ch
  • Communication Protocol: RS485,CAN
  • Contact form: 1NO 1NC

Pinouts

  • CAN bus
PINRaspberry Pi (BCM)Description
GNDGNDGround
SCKSCKSPI clock input
MOSIMOSISPI data input
MISOMISPSPI Data output
CSCE0Data/Command Selection
INT25Interrupt output
  • RS485 bus
PINRaspberry Pi (BCM)Description
GNDGNDGround
RXDRXDUART receive
TXDTXDUART transimit
  • Relay interfaces
PINRaspberry Pi (BCM)DescriptionGND!GNDGround
IN_CH1GPIO5Relay Channel 1
IN_CH2GPIO6Relay Channel 2
IN_CH3GPIO13Relay Channel 3
IN_CH4GPIO16Relay Channel 4
IN_CH5GPIO19Relay Channel 5
IN_CH6GPIO20Relay Channel 6

Install libraries

  • BCM2835 libraries
wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.68.tar.gz
tar zxvf bcm2835-1.68.tar.gz 
cd bcm2835-1.68/
sudo ./configure && sudo make && sudo make check && sudo make install
  • Install wringPi
sudo apt-get install wiringpi
wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i wiringpi-latest.deb
gpio -v
  • Python
sudo apt-get update
sudo apt-get install python-serial
sudo pip install python-can

Download Examples

Open a terminal and run the following commands to download the demo codes

sudo apt-get install p7zip-full
wget https://www.waveshare.com/w/upload/2/2f/RPi_Zero_Relay_Code.7z
7z x RPi_Zero_Relay_Code.7z  -r -o./RPi_Zero_Relay_Code
sudo chmod 777 -R RPi_Zero_Relay_Code/

CAN Bus

Configuration

  • Modify the config.txt file
sudo nano /boot/config.txt
Add the fololwing lines to the config.txt file and save
dtparam=spi=on
dtoverlay=mcp2515-can0,oscillator=16000000,interrupt=25,spimaxfrequency=3000000
  • Reboot
sudo reboot
  • Check if the driver is initalized normally
dmesg | grep -i '\(can\|spi\)'
The result should like the picture:

If the MCP2515 driver is not initalized normall you need to reboot and check if the devices are connected properly (H to H and L to L).

C examples

  • Run the receive example
cd ~/RPi_Zero_Relay_Code/CAN/wiringPi/receive/
make clean
make
sudo ./can_receive
After running the receive code, the terminal is waiting for data
  • Run the Send examples:
cd RPi_Zero_Relay_Code/CAN/wiringPi/send/
make clean
make
sudo ./can_send
Type data to send
In the receive terminal, you will get the packet related to id.

Python examples

  • Open a terminal and run the commands
cd RPi_Zero_Relay_Code/CAN/python/
#For receiving:
sudo python can_reveive.py
#For sending:
sudo python can_send.py

Connect to other CAN device

If you need to connect the RPi Zero Relay to other CAN devices, please note that:

  • Please check the connection, it should be H to H and L to L
  • Make sure that the baud rate of both sides are the same, the default baud rate of examples is 100K
  • Check if the CAN ID of both sides are the same
  • If data is always lost while transmitting, please decrease the baud rate and test it again.


RS485 Interface

Configuration

  • Open a terminal and run the command
sudo raspi-config
Choose Interfacing Options -> Serial -> No -> Yes
Disable the login shell function and enable the hardware serial port.
  • Reboot
sudo reboot
  • Connect the device, A to A and B to B

C examples

  • Run the receive example
cd RPi_Zero_Relay_Code/485/WiringPi/send
make clean
make
sudo ./485_receive
After running the receive code, the terminal is waiting for data
  • Run the Send example
cd RPi_Zero_Relay_Code/485/WiringPi/send
make clean
make
sudo ./485_send
  • Input data and send:


  • The receive terminal recieve and print:


Python examples

Open a terminal and run the commands:

cd RPi_Zero_Relay_Code/485/python/
#Receive example:
sudo python receive.py
#Send example:
sudo python send.py

Troubleshooting

If the RS485 cannot work normally, please check:

  • Please check if you have disabled the login shell function
  • Please check the connection, it should be A to A and B to B
  • Please test with USB to RS485, make sure that all the settings are correct.
Price: $37.89
Part Number: RPi Zero Relay
Brand: Spotpear
SKU: 0108320