# ESC (PWM) calibration for flight core v2

Source: https://forum.modalai.com/topic/2621/esc-pwm-calibration-for-flight-core-v2
Category: Flight Core and Legacy VOXL (https://forum.modalai.com/category/9/flight-core-and-legacy-voxl)
Tags: flight-core-v2
Posted: 2023-09-05 11:52:56 UTC by Anubhav
Replies: 2 · Views: 1087

## Anubhav · 2023-09-05 11:52:56 UTC

Hi Team, 
@modaltb 
I have been trying to calibrate the esc connected to my flight core v2. the esc pwm cable is connected to J7 port of FC. as given in docs for FC v2 "Standard PX4 drivers used" I assumed calibration should happen through QGC. Also I have tried the ESC calibration method mentioned [here](https://docs.modalai.com/flight-core-pwm-esc-calibration/). but I was unable to do the calibration through both attempts. 
The below output of calibration performed as given in the FC v1 ESC calibration. 
```
Using portname /dev/serial/by-id/usb-ModalAI_PX4_FMU_ModalAI_FCv2_0-if00
connecting...
Error: Unable to open port
```

Help from your side will be highly valuable. 

Thanks!
Anubhav

## Reply by modaltb (ModalAI staff) · 2023-09-05 19:19:07 UTC

@Anubhav I believe use QGC should work, I would not try to use the method for FCv1 (since we couldn't power over USB, you weren't able to use the standard method in QGC).

If you are powered off USB on FCv2 and use the QGC method, what issue are you having?

## Reply by wilkinsaf · 2023-11-10 22:37:54 UTC (in reply to modaltb)

@modaltb I seem to be having the same issue of the flight core power cycling when battery is plugged in. therefore, esc calibration fails