Quick Start

This guide introduces the FoBE Breakout GP8303 and how to use it.

Hardware diagram

The following figure illustrates the FoBE Breakout GP8303 hardware diagram.

Mechanical dimensions

FoBE Breakout GP8303 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 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: 18V to 36V
GND	Ground
OUTPUT	Analog current output: 4-20mA
GND	Ground

Advanced

Address Selection

GP8303 I2C Address

The GP8303 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.

1. Connect the FoBE Breakout GP8303 to the FoBE Quill ESP32S3 Mesh using the MFP interface.

2. Create a sketch or PlatformIO project, or follow the FoBE Quill ESP32S3 Programming Guide for pre-configuration.

3. Copy the following code into your sketch or PlatformIO project:

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

// GP8303 I2C Address and Registers
#define GP8303_ADDR 0x58
#define REG_DAC_DATA   0x02    // DAC data register

#define IIC_SDA_PIN    PIN_MFP3
#define IIC_SCL_PIN    PIN_MFP4

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

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

  Wire.begin(IIC_SDA_PIN, IIC_SCL_PIN);
  
  Wire.beginTransmission(GP8303_ADDR);
  if (Wire.endTransmission() == 0) {
      Serial.println("GP8303 DAC found.");
  } else {
      Serial.println("GP8303 DAC not found. Check connections.");
      while (1) delay(1000);
  }

  // set output current of 0-20ma(0-4095)
  setDACCurrent(GP8303_ADDR, 1024);
  Serial.println("DAC current set to 1024 (approx. 5mA).");
}

void loop() {
  delay(1000);
}

important

This example code sets the DAC output to 16mA. Make sure to connect an appropriate power supply (18V-36V) to the VIN terminal and connect your measurement equipment to the OUTPUT terminal.

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

4. Build and upload the project. You should measure 16mA output on the output terminal.

GP8303 DAC found.
DAC current set to 1024 (approx. 5mA).

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 GP8303 I²C address can be changed by soldering the appropriate address jumper pads on the board.
• Ensure proper 18V-36V power supply connection to VIN terminal for correct current output operation.