How to Flash Bluejay Firmware to BLHeli_S ESC

by Oscar
Flash Bluejay Esc Configurator Options Common Parameters

In this tutorial I will show you how to flash Bluejay firmware to BLHeli_S ESC. Bluejay is an open source firmware that improves ESC performance and gives you additional features and parameters.

Benefits of Bluejay Firmware

  • Improves flight performance by allowing Bi-directional DShot and RPM filtering
  • 24KHz, 48KHz and 96KHz PWM frequency
  • Ability to play start-up music

There are other BLHeli_S firmware that can bring you the similar benefits, like JESC and JazzMaverick (BLHeli_M). But JESC is not free (you pay per ESC), and JazzMaverick is no longer being updated (last update 2020). BlueJay is becoming the most popular firmware for BLHeli_S ESC as most people would probably prefer a free option that is regularly being updated.

This is currently my go-to firmware for all my BLHeli_S ESC, as it’s reliable and really makes my quads fly better.

How to Flash BlueJay to BLHeli_S ESC

You can flash it with the standalone configurator, but there is also a browser based configurator which is way easier:, that’s what I am using in this tutorial. Note that only Chrome based browser works.

If you used BLHeli Configurator before, the interface and steps should feel familiar.

Assuming the ESC is already connected to the flight controller in your drone, you just need to plug in the USB cable to the FC. And plug in the LiPo battery to power the ESC.

Click on “Select Serial Port”, then choose the COM port of the FC. (if you are doing this for the first time, your browser might ask you for permission to access the COM port)

Flash Bluejay Esc Configurator Serial Port Com

Click “Connect”, it will show you all the ESC available.

Flash Bluejay Esc Configurator Connect Read Setup

To flash these ESC with Bluejay, click “Flash All”.

Flash Bluejay Esc Configurator Firmware Target

Here are the options you need to select:

  • in Firmware, select “BlueJay”
  • in ESC, just leave it as it is
  • in version, pick the latest one
  • in PWM frequency, choosing a higher value will give you smoother motors and longer flight time (this is especially noticeably in tiny whoops), but in exchange, you will lose some power and snappiness. Take a look at my article explaining PWM frequency. A rule of thumb, select 96Khz for tiny whoops, 24Khz for 5″ racing quads, 48KHz for any sizes in between. I also prefer 48Khz for my 5″ freestyle quads. Anyway, try different numbers if you are not sure and see what works best for you

Now hit Flash. Done!


Configure BlueJay

First thing you want to do is to enable RPM filter in Betaflight, which I explained in this tutorial. This will make your drone fly so much better!


To configure ESC settings, connect to the configurator, and click “Read Setup” to popular all the ESC settings.

Flash Bluejay Esc Configurator Options Common Parameters

If this is the first time you flash BlueJay, you will notice there are some additional options in the configurator. The default options are fine for most people, but take a look at my article explaining what some of these options do.

Change Start-up Music

When you power on the quad, the motors make a start up sound. You can customize the sound in BlueJay.

Click Open Melody Editor, and you can edit the start up sounds for each ESC. There are a bunch of pre-made melodies in the drop down menu, but of course you can make your own too if you know how :)

Flash Bluejay Esc Configurator Melody Editor

When you have selected the melody you like, click on the “accept” button on each ESC, and Click “Write Melodies”.
That’s it.

Leave a Comment

By using this form, you agree with the storage and handling of your data by this website. Note that all comments are held for moderation before appearing.


Mac 16th March 2022 - 11:33 pm

Hi, Oscar,

I have an MCU F405 flight controler useing omnibusF4SD right now i still have Betaflight 3,5.7. I want to go to the newer Betaflight version so to have bi directional D shot, but my ESC still has BlHeli-S A-H-30. Will flashing the Bluejay to my ESC work for me or is my ESC and FC board too old to do so. I hear how some people get their ESC messed up when trying to do it.

Wraith 13th March 2022 - 3:40 am

I followed the flash steps exactly on my iFlight Alpha A75 and I seem to have a dead drone. The process stalled on ESC 2 and now nothing happens when I plug in the USB port. When I connect a battery I get a weak and broken startup tone with no lights or other functionality. Am I screwed or are there any recovery options?

Oscar 13th March 2022 - 8:49 pm

The bootloader on your ESC might be corrupted. It rarely happens, but I found this can happen in some badly designed/manufactured hardware when flashing firmware.
You can try recover it following this guide:

Wraith 14th March 2022 - 10:37 pm

Thank you so much for responding! I did find that article shortly after crying for help and now have an arduino nano on the way. My C2 interface is soldered up and ready. Hopefully this works, thank you for the great information!!