How many I2C inputs can the Helium Dev Board handle?

Question

The Helium Dev Board tech specs state that it has "Digital interrupt pads for I2C devices to wake the board". Does anyone know how many I2C sensor inputs in can handle in parallel? I'm not finding it documented anywhere.

Answer 1

Theoretically the DevBoard can handle 127 devices (based on addressing), but realistically with HW constraints in the DevBoard design, it can handle ~8-16 I2C slaves (depending on the inter-connecting wires between all of them). Capacitance plays a huge role in how stable the bus is. The Helium Extension boards are optimized to run several devices at once (up to 4 of each type) if needed.