Four addresses

Two pads, four answers

The INA219 has two address pins, A0 and A1. On this block each one is held at ground by a 10 kΩ resistor, and each has a pad on the back that, when bridged with solder, joins it to the 3V3 supply instead.

Both pads ship open. A1 is worth four and A0 is worth one, which is why the list skips from 0x41 to 0x44. The chip itself can answer at sixteen addresses, but the other twelve need its pins tied to SCL or SDA, which this board does not offer.

Bridging a pad

Tin the iron, touch it across both halves of the pad with a little solder, and take it away when the bead joins them. To undo it, wick the solder off. Then write the address on the board with a marker: once it is in a project, nothing on the outside says which is which.

Four blocks on one bus

Four blocks at four addresses can share one pair of wires, each in a different rail. In the sketch, each is its own object:

Adafruit_INA219 motor(0x40);    // both pads open
Adafruit_INA219 led(0x41);      // A0 bridged
Adafruit_INA219 logic(0x44);    // A1 bridged

Each block adds another pair of 10 kΩ pull-ups to the bus. Four in parallel is 2.5 kΩ, which an ESP32 still drives comfortably. For three or more rails at once, the triple-channel INA3221 does it with one chip.