Technical summary
Most current-measuring devices, such as our current measuring device, are only good for low-side measurement. This means that unless you want to involve a battery, you have to stick the measuring resistor between the target ground and the actual ground. This can cause problems with circuits, because electronics do not like it when ground references change and shift with varying current consumption. This chip is much smarter - it can handle high-side voltage measurement, up to +26VDC, even though it is powered with 3 or 5V. It will also report that high-side voltage, which is great for tracking battery life or solar panels.
A precision amplifier measures the voltage across the 0.1 ohm 1% sense resistor. Since the amplifier's maximum input difference is ±320mV, this means it can measure up to ±3.2 amps. With the internal 12-bit ADC, the resolution at ±3.2A is 0.8mA. With the internal gain set to the minimum of div8, the max current is ±400mA and the resolution is 0.1mA. Advanced hackers can remove the 0.1 ohm current sense resistor and replace it with their own to change the range (say 0.01 ohm to measure up to 32 amps with 8mA resolution)
We include a 6-pin header (so you can easily attach this sensor to a breadboard) as well as a 3.5mm socket so you can easily attach and detach your load. Usage is simple. Power the sensor itself with 3 to 5VCC and connect the two I2C pins to your microcontroller. Then connect your target supply to VIN+ and the load to ground at VIN-.
TECHNICAL DETAILS
0.1 ohm 1% 2W shunt resistor
Up to +26V measurement voltage
Current measurement up to ±3.2A, with a resolution of ±0.8mA
Note: the terminal block supplied with your product may be blue or black.
The GY-INA219 board uses 7-bit I2C addresses 0x40, 0x41, 0x44, 0x45, selectable with jumpers
