edit

# Grove - 4-Channel SPDT Relay

The Grove - 4-Channel SPDT Relay has four single pole - double throw (SPDT) switches. It only requires low-voltage and low current signals to control those switches. Specifically, you can use 5V DC to control max.250V AC or 110V DC.

We use an on-board STM32F030F4P6 to control the channels separately. The command from Arduino or other boards is transmit via the I2C interface, the on-board STM32F030F4P6 will parse the command, so that you can control the switch you want.

## Features¶

• High temperature resistant plastic shell
• Low power consumption
• Long lasting
• 0x00 ~ 0x7F

## Specification¶

Item Value
Working voltage 5V
Nominal Coil Current 89.3mA
TUV Certification Load 10A 250VAC/ 10A 30VDC
UL Certification Load 10A 125VAC 28VDC
Max. Allowable Voltage 250VAC/110VDC
Power Consumption abt. 0.45W
Contact Resistance 100mΩ Max.
Insulation Resistance 100MΩ Min. (500VDC)
Max. ON/OFF Switching 30 operation/min
Ambient Temperature -40°C to +85°C
Operating Humidity 45% to 85% r.h.
Contact Material AgCdO
Input Interface I2C
Default I2C Address 0x11 or 0x12
Available I2C Address 0x00 ~ 0x7F
Output interface 3 Pins DIP Female Screw Terminal-Green

Tip

For the load parameter, we provide two sets of certification data. Actually, the max. laod is 10A 250VAC/10A 30VDC.

## Applications¶

• Domestic appliance
• office machine
• monitor display
• audio equipment high rushing current use application

## Hardware Overview¶

### Pin Map¶

Note

• The switch 1-4 have the same pin fuction, so for the other switches, you can refer to NC1/COM1/NO1.
• On the back of the PCB, there are two interfaces: SWD and I2C. The SWD interface is used by default when programming firmware, if you want to use the I2C(actually work as the boot UART), you should set the BOOT High.

### Schematic¶

Relay control

K2 is the Relay module, there is a coil between pin1 and pin3 of K1. Defaultly, the COM2 will connect to NC2.If the pin3 of K1 connected to the grand, then this coil will be 'closed', so the COM2 will connect to NO2.

To open this coil, it requires about 90mA, however, normally the GPIO pin of Arduino only can afford 20mA(40mA max.). Therefor, we use a NPN transistors S9013 which can proviede 500mA.

The PA7 is pulled down by the 10k R2, if there is no signal, the 'Gate' of Q2 will be 0v, and Q2 is turned off, so that the K2 will be 'opened'. If PA7 becomes 5v, then the Q2 will be turned on. Pin3 of k2 will be connected to the GND of the system, for the K2 there will be 5V between pin3 and pin1, so the coil will be 'closed', and the COM2 will connect to NO2

Tip

The D1 is a flyback diode(kickback diode). A flyback diode is a diode connected across an inductor used to eliminate flyback, which is the sudden voltage spike seen across an inductive load when its supply current is suddenly reduced or interrupted. It is used in circuits in which inductive loads are controlled by switches, and in switching power supplies and inverters.

Bi-directional level shifter circuit

This is a typical Bi-directional level shifter circuit to connect two different voltage section of an I2C bus. The I2C bus of this sensor use 3.3V, if the I2C bus of the Arduino use 5V, this circuit will be needed. In the schematic above, Q17 and Q18 are N-Channel MOSFET 2N7002A, which act as a bidirectional switch. In order to better understand this part, you can refer to the AN10441

Note

In this section we only show you part of the schematic, for the full document please refer to the Resources

## Platforms Supported¶

Arduino Raspberry Pi BeagleBone Wio LinkIt ONE

Caution

The platforms mentioned above as supported is/are an indication of the module's software or theoritical compatibility. We only provide software library or code examples for Arduino platform in most cases. It is not possible to provide software library / demo code for all possible MCU platforms. Hence, users have to write their own software library.

## Getting Started¶

### Play With Arduino¶

#### Hardware¶

Materials required

Seeeduino V4.2 Base Shield Grove - 4-Channel SPDT Relay
Get One Now Get One Now Get One Now

Note

1 Please plug the USB cable gently, otherwise you may damage the port. Please use the USB cable with 4 wires inside, the 2 wires cable can't transfer data. If you are not sure about the wire you have, you can click here to buy

2 Each Grove module comes with a Grove cable when you buy. In case you lose the Grove cable, you can click here to buy.

• Step 1. Connect the Grove - 4-Channel SPDT Relay to the I2C port of the Base Shield.

• Step 2. Plug Grove - Base Shield into Seeeduino.

• Step 3. Connect Seeeduino to PC via a USB cable.

Note

If we don't have Grove Base Shield, We also can directly connect this module to Seeeduino as below.

Seeeduino Grove - 4-Channel SPDT Relay
5V Red
GND Black
SDA White
SCL Yellow

#### Software¶

Attention

If this is the first time you work with Arduino, we strongly recommend you to see Getting Started with Arduino before the start.

• Step 2. Refer to How to install library to install library for Arduino.

• Step 3. Restart the Arduino IDE. Open example via the path: File → Examples → Multi Channel Relay Arduino Library → four_channel_relay_control.

Or, you can just click the icon in upper right corner of the code block to copy the following code into a new sketch in the Arduino IDE.

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 #include Multi_Channel_Relay relay; void setup() { Serial.begin(9600); while(!Serial); /* Scan I2C device detect device address */ uint8_t old_address = relay.scanI2CDevice(); if((0x00 == old_address) || (0xff == old_address)) { while(1); } Serial.println("Start write address"); relay.changeI2CAddress(old_address, 0x11); /* Set I2C address and save to Flash */ Serial.println("End write address"); /* Read firmware version */ Serial.print("firmware version: "); Serial.print("0x"); Serial.print(relay.getFirmwareVersion(), HEX); Serial.println(); } void loop() { /** * channle: 8 7 6 5 4 3 2 1 * state: 0b00000000 -> 0x00 (all off) * state: 0b11111111 -> 0xff (all on) */ /* Begin Controlling Relay */ Serial.println("Channel 1 on"); relay.turn_on_channel(1); delay(500); Serial.println("Channel 2 on"); relay.turn_off_channel(1); relay.turn_on_channel(2); delay(500); Serial.println("Channel 3 on"); relay.turn_off_channel(2); relay.turn_on_channel(3); delay(500); Serial.println("Channel 4 on"); relay.turn_off_channel(3); relay.turn_on_channel(4); delay(500); relay.turn_off_channel(4); relay.channelCtrl(CHANNLE1_BIT | CHANNLE2_BIT | CHANNLE3_BIT | CHANNLE4_BIT); Serial.print("Turn all channels on, State: "); Serial.println(relay.getChannelState(), BIN); delay(2000); relay.channelCtrl(CHANNLE1_BIT | CHANNLE3_BIT); Serial.print("Turn 1 3 channels on, State: "); Serial.println(relay.getChannelState(), BIN); delay(2000); relay.channelCtrl(CHANNLE2_BIT | CHANNLE4_BIT); Serial.print("Turn 2 4 channels on, State: "); Serial.println(relay.getChannelState(), BIN); delay(2000); relay.channelCtrl(0); Serial.print("Turn off all channels, State: "); Serial.println(relay.getChannelState(), BIN); delay(2000); } 

Attention

The library file may be updated. This code may not be applicable to the updated library file, so we recommend that you use the first methods.

• Step 5. Open the Serial Monitor of Arduino IDE by click Tool-> Serial Monitor. Or tap the Ctrl+Shift+M key at the same time.

Success

If every thing goes well, you will get the result. Meanwhile, you will see the on-board LEDs alternately lit and extinguished.

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Scanning... I2C device found at address 0x12 ! Found 1 I2C devices Start write address End write address firmware version: 0x1 Channel 1 on Channel 2 on Channel 3 on Channel 4 on Turn all channels on, State: 1111 Turn 1 3 channels on, State: 101 Turn 2 4 channels on, State: 1010 Turn off all channels, State: 0 Channel 1 on Channel 2 on 

Note

#### Function description¶

Function Description
getChannelState() get the state of every channel, for instance "State: 1111", which means all the relay is turned on
getFirmwareVersion() get the firmware version burn into the on board MCU
channelCtrl(uint8_t state) to change all channels you picked immediately, the state parameter list:

CHANNLE1_BIT or 0x01
CHANNLE2_BIT or 0x02
CHANNLE3_BIT or 0x04
CHANNLE4_BIT or 0x08

e.g.
channelCtrl(CHANNLE2_BIT|CHANNLE3_BIT),will turn on the channel 2,channel 3
channelCtrl(01|02|08), will turn on the channel 1,channel 2 and channel 4.
channelCtrl(0), will turn off all the channels.
turn_on_channel(uint8_t channel) to turn on the single channel.
e.g.
turn_on_channel(3), will turn on the channel 3
turn_off_channel(uint8_t channel) to turn off the single channel.
e.g.
turn_off_channel(3), will turn off the channel 3

In case you want to change the address, you need to set the address before use. For example, we want to change it into 0x2f. We can use the following code.

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 #include Multi_Channel_Relay relay; void setup() { Serial.begin(9600); while(!Serial); /* Scan I2C device detect device address */ uint8_t old_address = relay. ; if((0x00 == old_address) || (0xff == old_address)) { while(1); } Serial.println("Start write address"); relay.changeI2CAddress(old_address,0x2f); /* Set I2C address as 0x2f and save it to the EEPRom */ Serial.println("End write address"); /* Read firmware version */ Serial.print("firmware version: "); Serial.print("0x"); Serial.print(relay.getFirmwareVersion(), HEX); Serial.println(); } 

## FAQ¶

Q1: How to burn the firmware?

A1: We recommend you use the J-Link burner and the WSD interface to burn the firmware.

Factory firmware

We recommed you use the J-flash for the software:

J-flash

## Project¶

This is the introduction Video of this product, simple demos, you can have a try.

## Tech Support¶

Please do not hesitate to submit the issue into our forum.