About this item

The CJMCU-219 is a compact and precise power monitoring module based on TI’s INA219 chip, designed for bi-directional measurement of current and voltage over I²C with minimal drift. Featuring a 0.1 Ω, 1% tolerance, 2 W shunt resistor and a precision amplifier capable of detecting up to ±320 mV, it measures currents up to ±3.2 A with a fine 0.8 mA resolution, while enabling lower-current measurements (±400 mA) at 0.1 mA resolution using gain adjustment. Packing a 12-bit ADC and programmable calibration registers, the module delivers stable, accurate readings—including calculated power values—without needing dual instruments. Its I²C interface supports SMBus and fast mode (up to 3.4 MHz) and includes timeout and averaging filters to improve resilience in noisy environments. The board operates from a single 3.0–5.5 V supply, senses bus voltages up to 26 V, and maintains ±1% accuracy within –40 °C to +85 °C. With its small PCB footprint (~0.9" × 0.8"), lightweight design (~1.9 g), and optional 16 I²C address selections, the CJMCU-219 is an ideal, compact solution for power monitoring in embedded systems, battery management, IoT devices, and beyond.