Example Code for Arduino-PWM Mode Output 20mA in 4-20mA Range

Hardware Preparation

• DFR1229 GP8600: I2C&PWM to 0-5V&0-10V&4-20mA ×1
• DFR0654 FireBeetle 2 ESP32-E ×1
• Multimeter ×1
• Several jumper wires

Software Preparation

• Download and install Arduino IDE: [Download Link]
• Download dependent libraries:
  • DFRobot_GP8XXX Library: [Download Link]
  • DFRobot_RTU Library: [Download Link]
• Library Installation Guide: [View Installation Tutorial]

Wiring Diagram

Connect the module to the ESP32-E as shown in the diagram. The core corresponding relationships are as follows:

• Module PWM pin "+" → ESP32-E 3.3V
• Module PWM pin "-" → ESP32-E GND
• Module PWM pin "D" → ESP32-E GPIO13 (PWM output pin)

Other Preparation Work

• DIP switch configuration: A0=0, A1=1, A2=1 (output range = 4-20mA)

In PWM mode, A0 must not be set to 1; otherwise, the device may be damaged.

Sample Code

Open Arduino IDE, copy the following code, and upload it to the ESP32-E:

#include <DFRobot_GP8XXX.h>

// Define the PWM pin as 13 (applicable to ESP32)
const int pwmPin = 13;
DFRobot_GP8600_PWM GP8600(pwmPin);

void setup() {
  // Initialize the sensor
  GP8600.begin();
  
  // Set output data (PWM range for ESP32 is 0-1023)
  double data = 1023;  // Maximum output value
  GP8600.setDACOutData(max(data, 42.5));
}

void loop() {
  // No operations required in the loop
}

Result

1. Set the multimeter to the "DC A" range;
2. Connect the red probe to the module's "OUT" terminal and the black probe to the module's "GND" terminal;
3. Under normal conditions, the measured current should be close to 20mA. In this example, the actual measured output current is 20.12mA.