In previous post we discussed CPU power consumption in PIP-Watch. Today we look into Bluetooth power consumption because it is significant as much as the CPU power.

Bluetooth Radio States

Practically the only significant part that consumes a lot of power in Bluetooth modems is their radio transceiver. If the radio is switched off the module draws only small quiescent current (less than 2mA in BTM431). Radio is activated by modem to perform one of the following three actions:

• to do a page scan,
• to do an inquiry scan,
• to transfer data to a connected device.

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