I recently asked RAK team for hardware suggestion to start my first project on temperature and humidity monitoring. I was advised to get the WisBlock Kit 4. It has been a couple of weeks already testing the devices.
The battery I use is Lithium Polymer Battery 1500mAh. At first test it took only few days to drain to 0%.
So I refined the code and removed any unnecessary code such as Serial output, OLED, non-required readings, frequency of reading, etc. Now it’s day 4 at 70% battery which is not my goal. I am looking for 12 months battery life.
Can someone please direct me towards better battery preservation. I only need to read temperature and humidity and report them every 5 or 10 minutes.
Both examples are not optimized for battery consumption.
Try RAK4631-Kit-4-RAK1906.
I have that running from a 3200mAh battery with send interval of 10 minutes for ~6 months before I need to recharge the battery.
Thank you for the useful output.
Actually, I came cross this page before but I wasn’t able to run PlatformIO. I will try again for sure.
If you don’t mind, what’s the name of the second software? I should do the same rather than watching the battery performance for days
And do you think there will be any difference if I use RAK1901 sensor instead of RAK1906?
Grafana is a very powerful software I used it late 2018. However, I didn’t like the integration options available at TTN so I built my own simple dashboard
The power measurements are done with a Nordic Power Profiler Kit II
Available at multiple distributors. Costs around 90 US$ and is a very helpful tool.
For the difference between the RAK1901 and RAK1906, the RAK1901 has a lower power consumption but doesn’t offer the barometric pressure measurement and the gas resistance.
The gas resistance is actually only useful if you use the (closed source) BSEC library from Bosch to calculate an air quality index from T, H, P and gas resistance values of the BME680.
Thank you heaps Bernd!
I will definitely get RAK1901 as I only need temperature and humidity.
One last question please, there is a temperature difference about 1 to 2 °C higher than multiple battery-powered thermostats I have at home. I read it’s heat from the board most likely.
What is the best way to measure/calibrate the readings?
right now I am subtracting 1.5 just before representing the data.
I have no formula for the temperature compensation.
If the accuracy is important, I would try to separate the RAK1901 from the Base Board using our FPC sensor extension cable RAK19005
Another point about temperature higher than other devices, specially for the RAK1906.
The RAK1906 has the gas resistance sensor to be used with the BSEC library to get air quality index.
This gas resistance sensor works with an internal heating element in the chip. My experience is that if it is not disabled, it has an influence on the temperature measurement of the BME680.
