Community Forum

Measuring voltage Servo Rail in mission planner

(Marc Lebret) #24

Do you look at the right place to find Batt2 voltage?


In the HUD, I have my Power module battery voltage (11.57)

In the Quick screen, I choose Batt2 Voltage (double click to select display item).

Value displayed is 5.00v, it change slightly when switching on led lighting.

My voltage multiplier is quick and dirty guess. I did not check the real bec servo rail voltage with multimeter before.

(Barry Bolton) #25


(Barry Bolton) #26


Which pin do you provide power too? I have mine on pin 14.

(Barry Bolton) #27

NVM just moved it to Pin 2 and still no voltage reading.

(Marc Lebret) #28

Same pin for me. Ground and 5v.

(Barry Bolton) #29

I see I am getting Log errors. Might be something or might be nothing. let me see if I have any luck when replacing the SD card.

(Barry Bolton) #30

Nope nada not a thing. Not sure what is wrong. EMLID any one

(Tatiana Andreeva) #31

Hi @Barry_Bolton,

Can you please specify which log errors you got?

(Barry Bolton) #32

It was a bad SD card.

(Barry Bolton) #33

Tatiana do you think you can ask your engineers over at Emlid to look into the issue of the 0 reading as per my post?

(Tatiana Andreeva) #34


Could you please elaborate on what’s the issue with 0 reading?

(Barry Bolton) #35

Tatiana. The whole thread is there. You even commented on the post. The issues is that no matter what I adjust in settings I always get 0 reading on my BATT2

(Marc Lebret) #36

Can you check your RCIO firmware version?


(Barry Bolton) #37

Same as yours marc

(Tatiana Andreeva) #38

Hi Barry,

In QGC, please try to configure the same settings for the Battery 1.

Check the screenshot below for more details:


(Barry Bolton) #39

I have a question about the input.

I’m using a normal UBEC to power the servo rail, Could this be an issue?

(Tatiana Andreeva) #40


Could you please run the ADC example and post here the output?
Just to check whether the servo rail is supplied with power.

(Barry Bolton) #41

OK I will do but I have already flown with the power going into the servo rail. If I only plug the power in the power rail the PI and Navio powers up

(Barry Bolton) #42

Hello Tatiana.

That is a little above my Coding skills. Do I have to for example type “cd Python
python ADC.py”

Directly into the CLI? If I type cd Python it just tells me no suck file or directory

(Tatiana Andreeva) #43

Hi Barry,

May I ask you to run this command instead?
cat /sys/kernel/rcio/adc/ch1