INA228 Display Xiao

xiao_ina228.ino

#include <Arduino.h>
#include <Wire.h>
#include <U8g2lib.h>
#include <Adafruit_INA228.h>

// =====================
// OLED (128x64 SSD1306)
// =====================
U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(
  U8G2_R0,
  /* reset = */ U8X8_PIN_NONE
);

// =====================
// Config
// =====================
#define UPDATE_INTERVAL_MS 1000  // ms

// =====================
// INA228
// =====================
Adafruit_INA228 ina228;


uint32_t lastUpdate = 0;
bool sensorOK = false;

// =====================
// Helpers
// =====================
void drawError(const char *msg) {
  u8g2.clearBuffer();
  u8g2.setFont(u8g2_font_7x14_tf);
  u8g2.drawStr(0, 24, "ERROR:");
  u8g2.drawStr(0, 44, msg);
  u8g2.sendBuffer();
}

void drawMeasurements(float voltage, float current_mA) {
  char buf[20];

  u8g2.clearBuffer();
  u8g2.setFlipMode(1);
  u8g2.setFont(u8g2_font_logisoso18_tf);

  // Voltage (top)
  snprintf(buf, sizeof(buf), "%.2f V", voltage);
  u8g2.drawStr(0, 26, buf);

  // Current (bottom)
  if (current_mA >= 1000.0f) {
    snprintf(buf, sizeof(buf), "%.2f A", current_mA / 1000.0f);
  } else {
    snprintf(buf, sizeof(buf), "%.0f mA", current_mA);
  }
  u8g2.drawStr(0, 56, buf);

  u8g2.sendBuffer();
}

// =====================
// Setup
// =====================
void setup() {
  Serial.begin(115200);
  delay(2000);

  // I2C (required on ESP32-C3)
  // Wire.begin(SDA, SCL);

  // OLED
  u8g2.begin();
  u8g2.clearBuffer();
  u8g2.setFont(u8g2_font_7x14_tf);
  u8g2.drawStr(0, 24, "Initializing...");
  u8g2.sendBuffer();

  // INA228
  if (!ina228.begin()) {
    Serial.println("INA228 not found");
    drawError("INA228 missing");
    sensorOK = false;
    return;
  }

  ina228.setAveragingCount(INA228_COUNT_1024);
  ina228.setShunt(0.015, 10.0);

  sensorOK = true;
  Serial.println("INA228 initialized");

  u8g2.clearBuffer();
  u8g2.drawStr(0, 24, "INA228 Ready");
  u8g2.sendBuffer();
}

// =====================
// Loop
// =====================
void loop() {
  if (millis() - lastUpdate < UPDATE_INTERVAL_MS) {
    return;
  }
  lastUpdate = millis();

  if (!sensorOK) {
    return;
  }

  float voltage = ina228.readBusVoltage();    // volts
  float current_mA = ina228.readCurrent();    // milliAmps

  Serial.printf("V=%.3f V  I=%.1f mA\n", voltage, current_mA);

  drawMeasurements(voltage, current_mA);
}