nrf51422 does not advertise with low voltage battery

[nirmal@nordic]

Hi, Everyone,

I have firmware working with our custom pcbs. It works fine with new 3.3v battery.

But somehow it does not advertise anything with used battery having voltage even up to 2.89v

What could be the reason??

My debugger even stops saying it can read some registers... My current consumption is as low as 22uA, when measured... and I manually do put battery again to restart the beacon after programming to make sure it is not running in debug mode anymore ..

[Dave_couling]

How much capacitance do you have on your power line?

Advertising pings are the most power-intensive things the radio can do. The 22uA you are measuring is the average current, but not the peak current. At the peak current, there will be voltage-drop across the battery's IR. This can cause a voltage-brown out at Low Battery where the IR is above 60ohms.

[nirmal@nordic]

I dont have any capacitors to the input power line please see the image attached here

[Dave_couling]

If your lack of capacitance that isn't the root cause of your issue, it certainly will become an issue for you in the future. Capacitors help lower the peak currents drawn from the Battery. This is crucial for coin-cell batteries which do not act well under pulse-current draw. I'd add 47uF (min) to help reduce the load on your battery.

[Øyvind Karlsen]

I agree with Dave here. You should also be careful that you consider the specified pulse draw in the product specification for your battery. If you draw a lot of current from a battery that does not support it you will see significant voltage drop, which can cause power fail resets.