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

• RS485 bus

• Relay interfaces

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.