Using INA219 with Arduino to Measure Voltage, Current, and Power in a Circuit

Recently, while working on a DIY project, I needed to measure voltage, current, and power in the circuit. After comparing several chips, I decided to use the INA219 chip from Texas Instruments. Coincidentally, I had previously used an INA219 module to build a simple power meter, which made me quite familiar with it.

The official introduction of INA219 is as follows:

The INA219 is a current shunt and power monitor with an I2C- or SMBUS-compatible interface. The device monitors both shunt voltage drop and bus supply voltage, with programmable conversion times and filtering. A programmable calibration value, combined with an internal multiplier, enables direct readouts of current in amperes. An additional multiplying register calculates power in watts. The I2C- or SMBUS-compatible interface features 16 programmable addresses.

The usage of INA219 is relatively simple. Data can be read directly through the I2C bus, and it supports a maximum measurement voltage of 26V with 12-bit precision, which satisfies the requirements in most scenarios. On the OSHWHub, many USB power meters also use this chip.

Schematic Diagram

Schematic for INA219

INA219 requires only a few external components to operate. Adding a bypass capacitor to the…