# How to: Seeker ESC calibration

Source: https://forum.modalai.com/topic/584/how-to-seeker-esc-calibration
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2021-12-01 18:31:02 UTC by alarm_hq
Replies: 8 · Views: 1520

## alarm_hq · 2021-12-01 18:31:02 UTC

I'm unsure how to calibrate the ESCs on the seeker.

I can't use qgroundcontrol as the seeker doesn't have 5v input, non battery power input as documented [here](https://docs.modalai.com/flight-core-pwm-esc-calibration/)

However, using the [px4-esc-tool](https://gitlab.com/voxl-public/flight-core-px4/px4-esc-cal-tool)  to calibrate the seeker's ESC, the prompts request your to remove J1007 from the VOXL Flight. This connector is not populated from the factory. 

Any advice? Should I just ignore it and move to the next step?

## Reply by Chad Sweet (ModalAI staff) · 2021-12-01 18:32:59 UTC

There is no need to calibrate the Seeker's ESC. They use a closed loop RPM control with parameters specified at the factory.

So we can improve our documentation, where is that step listed?

## Reply by Chad Sweet (ModalAI staff) · 2021-12-01 18:33:32 UTC

The Seeker (and all of our drones), come ready to fly out of the box.

## Reply by alarm_hq · 2021-12-01 18:43:30 UTC

And if I've already made the "mistake" of reflashing px4 firmware, is the closed loop RPM control affected?

## Reply by Chad Sweet (ModalAI staff) · 2021-12-01 19:05:01 UTC

Ah :-) I'll ping some more folks. Don't know off the top of my head.

## Reply by modaltb (ModalAI staff) · 2021-12-01 19:16:17 UTC

Mainline PX4 doesn't have our ESC driver (yet), so if was from the QGC auto update, it's likely wiped that driver out!

Here's the .px4 binary that has support (what we are shipping with).

info:
https://docs.modalai.com/flight-core-firmware/

v1.11.3-0.0.5:
https://storage.googleapis.com/modalai_public/flightcore-releases/1.11.3-0.0.5.modalai_fc-v1_default.px4

## Reply by modaltb (ModalAI staff) · 2021-12-01 19:17:24 UTC

Source code for reference: https://github.com/modalai/px4-firmware/tree/modalai-1.11/src/drivers/uart_esc/modalai_esc

## Reply by alarm_hq · 2021-12-01 19:19:17 UTC

Awesome, that was the driver I had used. Thanks for clarifying!

## Reply by James Strawson (ModalAI staff) · 2021-12-01 19:20:31 UTC (in reply to alarm_hq)

@alarm_hq said in [How to: Seeker ESC calibration](/post/2702):
> And if I've already made the "mistake" of reflashing px4 firmware, is the closed loop RPM control affected?

The ModalAI ESCs used on Seeker have their own firmware and settings stored on the ESC itself, independent from PX4 so your ESC is fine after changing PX4 firmware.