nrf52832 sensor board

[evs]

Hi,

I didn't like the boards i found so far. So I made something:

I made it as versatile and small as possible. With still the ability to solder it by hand, if you have some experience (and a loop).

• I used a CR123 lithium battery. because it is alway disappointing how much current it uses and that basically dictate the size of the PCB.
• I could think of and sensor that is solderable by hand that I can add. But i added a i2c connector for that.
• i added a expansion connector for future use.For thinks like: wifi bridge touch buttons and more

So please tell me what you think. things to improve or things that that are still needed to make in work with mysensors.
When I made my first prototype I will make it available hopenhardware.io
Thanks!

[gohan]

Have you ever considered using a single LiFePo4 AA battery? I know it you make it a little bigger, but it could be of a different shape other than round

[evs]

If you are aiming for a year + battery life in room+ temperatures. Any other battery, except lithium battery, The battery life is determined by there self discharge.

Don't underestimate the danger of batteries. The internal resistance in a LiFePo4 is really low. So if something bad happens you got a fire hazard. Special unknown Chinees brands. Youtube is full of li-ion fire hazards/

[gohan]

If you read around, LiFePO4 batteries are considered safer than Li-Po as they don't explode as easily.

[evs]

@gohan more safe. So what is the more part?? What happens if there is a problem and they got shorted. then there is a lot of energy released in a real short of time.
batteries with a real low internal resistance are not suited for use where there are unguarded. Only if you really know what you are doing and knows that the batteries are of high quality. I worked at a company that made LiFePO4 batteries and battery monitor hardware. And i see the result of mishaps.