Current and a knob on an ESP32-C3

// A load's current and its voltage, two ways: an INA219 at 0x40 and an
// ADS1115 at 0x48 on the ESP32-C3's I2C pins, GPIO 8 and 9.
//
// The INA219 is in series with the load: 3.3 V into VIN+, VIN- on to a 220
// ohm resistor to ground. Its 0.1 ohm shunt is a real resistor in the
// circuit, and the chip reads the few millivolts across it to 10 uV, and the
// voltage on the load side to 4 mV. The library writes the chip's calibration
// in begin(); without it the current register reads zero whatever flows.
//
// The ADS1115's A0 is on the same load-side node, so the two chips measure
// the same voltage: the INA219 in 4 mV steps, the ADS1115 at GAIN_ONE in
// 125 uV steps, a single-shot conversion taking 7.8 ms at the default rate.
//
// Change the resistor in the properties panel and watch both follow.

#include <Wire.h>
#include <Adafruit_INA219.h>
#include <Adafruit_ADS1X15.h>

Adafruit_INA219 ina219;
Adafruit_ADS1115 ads;

void setup() {
  Serial.begin(115200);
  if (!ina219.begin()) Serial.println("no INA219 at 0x40");
  ads.setGain(GAIN_ONE);
  if (!ads.begin()) Serial.println("no ADS1115 at 0x48");
}

void loop() {
  int16_t counts = ads.readADC_SingleEnded(0);
  Serial.print("load ");
  Serial.print(ina219.getCurrent_mA());
  Serial.print(" mA, ");
  Serial.print(ina219.getPower_mW());
  Serial.print(" mW   INA219 says ");
  Serial.print(ina219.getBusVoltage_V());
  Serial.print(" V, ADS1115 says ");
  Serial.print(ads.computeVolts(counts));
  Serial.print(" V (");
  Serial.print(counts);
  Serial.println(" counts)");
  delay(500);
}