[FX30 Cat1] Measure power voltage

Good morning everyone,

I need to detect when power reaches low voltage limit which is 4.75V according to documentation.
Is there any way to measure power voltage on PIN 1 provided by the power connector?
I couldn’t find any GPIO mapping to this PIN1 in the documentation.

Thanks for your reply.

1 Like

Hi demathos,

According to FX30 User Guide:
Pin 1 (Power)—Use the red wire in the DC cable to connect Pin 1 to the power source.
You can connect Pin 3 (On/Off) to power


You can measure power voltage on PIN3 (GPIO24).

Hi @demathos,
You could use the analog input pin at external IO2, but you may need some circuitry since the maximum voltage input is 10V.

Hi @Donald,
Thanks for your reply. I already use PIN3 to detect power down in my software by using legato GPIO api (le_gpioPin24_Read function). This function only return a boolean.
Could you explain how you measure power voltage on GPIO24?

Hi @cchenry,
Thanks for your reply. I like the idea of using IO2 as an analog input. The circuit needed to adapt voltage inside 0-10V range is currently being prepared. I will get back to you when it’s ready.