Getting Started with FoBE Breakout GP8403

Introduction

The FoBE Breakout GP8403 integrates the Linearin-GP8403 I2C to dual-channel voltage DAC converter and the ST- M24C64 EEPROM for calibration data storage. The module converts 12-bit digital values (0x000-0xFFF) to precise 0-5V or 0-10V analog voltage output with excellent linearity and accuracy. Multiple connectivity options are provided for easy integration into various applications.

Applications

General signal conversion and conditioning
Motor speed regulation and LED dimming control
Inverter and power supply control systems
Industrial analog signal isolation and processing

Key Features

GP8403
- Dual-channel 12-bit DAC resolution (0x000-0xFFF input range)
- Selectable output ranges: 0-5V or 0-10V per channel
- Excellent output voltage accuracy: < 0.5% (0.1% with calibration)
- Outstanding voltage linearity: 0.1%
- Output short circuit protection with automatic recovery
- I²C interface with programmable address
- Input I²C signal high level: 2.7V to 5.5V
- Power supply voltage: 9V to 36V
- Low power consumption: < 5mA
- Fast startup time: < 2ms
- Wide operating temperature: -40°C to +85°C
M24C64 EEPROM
- 64Kbit (8KB) data storage capacity
- 32-byte page size for efficient writing
- Write protection for entire memory array
- Enhanced ESD/Latch-Up protection
- More than 4 million write cycles endurance
- More than 200-years data retention
Connectivity
- MFP-IIC interface (JST-SH1.0 4-Pin)
- 6 x 2.54mm Pin Header
- 4 x 3.81mm Screw Terminal Block

Hardware diagram

The following figure illustrates the FoBE Breakout GP8403 hardware diagram.

Mechanical dimensions

FoBE Breakout GP8403 is a single-sided 25.4mm x 50.8mm (1" x 2") 1.6mm thick PCB with two SH1.0 4-pin connectors, a set of 6-pin 2.54mm header holes, and 4 x 3.81mm screw terminal blocks for power and dual output. Fixing by 4 x 1.6mm Screw holes.

Interfaces

The module provides dual 4-Pin JST SH1.0 connectors, compatible with STEMMA QT / Qwiic.

2.54mm 6-Pin	JST-SH1.0	Features
NC	—	Not connected
GND	GND	Ground
3V3	3V3	Power supply, Only 3.3V
SDA	SDA	I2C-Data line
SCL	SCL	I2C-Clock line
NC	—	Not connected

Output Terminal Block

3.81mm Terminal	Features
VIN	Power supply: 9V to 36V
GND	Ground
CH1	Channel 1 voltage output: 0-5V/0-10V
CH0	Channel 0 voltage output: 0-5V/0-10V

Advanced

Address Selection

GP8403 I2C Address

The GP8403 I²C address can be configured using solder pads A0-A2:

A2	A1	A0	I²C Address
0	0	0	0x58 (Default)
0	0	1	0x59
0	1	0	0x5A
0	1	1	0x5B
1	0	0	0x5C
1	0	1	0x5D
1	1	0	0x5E
1	1	1	0x5F

EEPROM I2C Address

The M24C64 EEPROM I²C address can be configured using solder pads A0-A2:

A2	A1	A0	I²C Address
0	0	0	0x50 (Default)
0	0	1	0x51
0	1	0	0x52
0	1	1	0x53
1	0	0	0x54
1	0	1	0x55
1	1	0	0x56
1	1	1	0x57

Programming

Running with FoBE Quill ESP32S3 Mesh

Let's get started with the FoBE Quill ESP32S3 Mesh using the MFP interface.

Connect the FoBE Breakout GP8403 to the FoBE Quill ESP32S3 Mesh using the MFP interface.

Create a sketch or PlatformIO project, or follow the FoBE Quill ESP32S3 Programming Guide for pre-configuration.
Copy the following code into your sketch or PlatformIO project:

#include <Arduino.h>
#include <Wire.h>

#define GP8403_ADDR 0x58
#define GP8403_MODE_005V                0x00 // 0-5V output
#define GP8403_MODE_005_010V            0x10 // 0-5V and 0-10V output
#define GP8403_MODE_010_005V            0x01 // 0-10V and 0-5V output
#define GP8403_MODE_010V                0x11 // 0-10V output

#define GP8403_MODE_ADDRESS             0x01
#define GP8403_CHANNEL0_ADDRESS 0x02        // Channel 0 data register
#define GP8403_CHANNEL1_ADDRESS 0x04        // Channel 1 data register

#define IIC_SDA_PIN PIN_MFP3
#define IIC_SCL_PIN PIN_MFP4

bool setDACVoltage(uint8_t address, uint16_t vol_levl, uint8_t channel_reg) {
    uint8_t hibyte = ((vol_levl << 4) & 0xff00) >> 8; 
    uint8_t lobyte = ((vol_levl << 4) & 0xff);
    vol_levl = lobyte << 8 | hibyte;
    Wire.beginTransmission(address);
    Wire.write((uint8_t)channel_reg);
    Wire.write((uint8_t)(vol_levl >> 8));
    Wire.write((uint8_t)(vol_levl & 0xFF));
    return (Wire.endTransmission() == 0);
}

void setup() {
    Serial.begin(115200);
    
    pinMode(PIN_PERI_EN, OUTPUT);
    digitalWrite(PIN_PERI_EN, HIGH);

    Wire.begin(IIC_SDA_PIN, IIC_SCL_PIN);
    
    Wire.beginTransmission(GP8403_ADDR);
    if (Wire.endTransmission() == 0) {
        Serial.println("GP8403 DAC found.");
    } else {
        Serial.println("GP8403 DAC not found. Check connections.");
        while (1) delay(1000);
    }

    Wire.beginTransmission(GP8403_ADDR);
    Wire.write((uint8_t)GP8403_MODE_ADDRESS);
    Wire.write((uint8_t)GP8403_MODE_005_010V);
    if(Wire.endTransmission() == 0){
        Serial.println("GP8403 mode set to 0-5V and 0-10V output.");
    } else {
        Serial.println("Failed to set GP8403 mode.");
        while (1) delay(1000);
    }

    setDACVoltage(GP8403_ADDR, 2047, GP8403_CHANNEL0_ADDRESS);
    Serial.println("Channel 0 set to approximately 2.5V.");

    setDACVoltage(GP8403_ADDR, 2047, GP8403_CHANNEL1_ADDRESS);
    Serial.println("Channel 1 set to approximately 5V.");
}

void loop() {
  delay(1000);
}

important

This example code sets Channel 0 to 3V and Channel 1 to 8V in 0-10V mode. Make sure to connect an appropriate power supply (9V-36V) to the VIN terminal and connect your measurement equipment to the CH0 and CH1 terminals.

# platformio.ini
[env:fobe_quill_esp32s3_mesh]
platform = FoBE Espressif 32
board = fobe_quill_esp32s3_mesh
framework = arduino
monitor_speed = 115200
monitor_raw = true

Build and upload the project. You should measure 3V on channel 0 and 8V on channel 1 using a multimeter.

GP8403 DAC found.
GP8403 mode set to 0-5V and 0-10V output.
Channel 0 set to approximately 2.5V.
Channel 1 set to approximately 5V.

note

If you want to use custom pins, you can change the IIC_SDA_PIN and IIC_SCL_PIN definitions to your desired GPIO pins.
The GP8403 I²C address can be changed by soldering the appropriate address jumper pads on the board.
Ensure proper 9V-36V power supply connection to VIN terminal for correct voltage output operation.
Each channel can be independently configured for 0-5V or 0-10V output range.

Resources

[PDF] FoBE Breakout GP8403 Datasheet

[PDF] FoBE Breakout GP8403 Schematic

[PDF] FoBE Breakout GP8403 Dimension

[OBJ] FoBE Breakout GP8403 3D Model

Introduction​

Applications​

Key Features​

Hardware diagram​

Mechanical dimensions​

Interfaces​

Output Terminal Block​

Advanced​

Address Selection​

GP8403 I2C Address​

EEPROM I2C Address​

Programming​

Running with FoBE Quill ESP32S3 Mesh​

Resources​