Current consumption of weather station is around 28-38 µA depending on transmission power, CR2477 battery should last for 2-3 years indoors. Stretching the battery life is easiest by lowering the transmission frequency, 8 µA current consumption can be achieved. At that consumption the limiting factor for lifetime is coin cell shelf life. PM me if you want to have a precompiled package with lower transmission rate, later we’ll make the tags configurable by Bluetooth.
Latest firmware transmits at 2 Hz in URL mode, 1 Hz in RAW mode.
April firmware transmits at 2 Hz in both modes.
Right now easiest way to configure transmission power and is to change the setting in configuration and recompile. [EDIT] Same for intervals.
Currently both accelerometer and BME280 can be configured over GATT, however there is not exact date on when the transmission power and interval is configurable. Probably sometime during 2017.
I’ve used standard CR2477 batteries in freezer near -30C, but as the battery manufacturer of standard battery does not promise the battery will work at that temperature the tag might shut down.
CR2450HT are high temperature range batteries, they should reach from -40 to +125 C.
Can I ask what variable you need to change from these to reduce the transmission frequency to for example 15 seconds? The APPLICATION_ADV_INTERVAL? Or some of the loop timers?
Loop timers control the rate at which the sensors are read but not the sampling rate of sensors themselves.
ADV_INTERVALs control the bluetooth transmission rate. If you set it to higher than the loop timers same data will be sent several times, if slower some data won’t be sent.
Valid range for the bluetooth advertisement rate is 100 ms … 10 000 ms, lower or higher should return error from the softdevice.
So it is not possible to set it to 10010 as that is higher than the max value. Is it okay if I set it to 9090?
And this would mean that the some measured data will not be sent, as the loop timers are lower values, meaning the loop will execute like 5 times between transmissions. Do I understand this right?
Not right now, we do have some proof-of-concepts of logging but nothing ready to use yet.
No, WiFi consumes too much power for a coin cell powered tag. You might be interested in Ruuvi Dongle project which collects Ruuvi data and sends it to cloud via WiFi.