A few months ago, Holux released a new firmware for its M-241 GPS logger. This latest version v1.12 allows to turn off Bluetooth whereas before it was always on – whether used or not. Turning off BT is expected to lower the overall current consumption of the device. But does it really?
To find out more, Oliver and I set out to measure the power consumption. In theory, this is quite simple: Get your hands on a fairly accurate current meter (in our case a Fluke 87), put it in series to the power supply circuit and measure the current in various states.