BLHeli_32 ESC Firmware Overview

We have official BLHeli_32 confirmation from BLHeli Developers. Let’s find out what it is about, what advantages it brings, and what changes there are moving forward.

What is BLheli_32?

BLHeli is an ESC firmware, and BLHeli_32 is the 3rd generation after BLHeli and BLHeli_S.

BLHeli_32 is written for ESC‘s that utilize 32-bit MCU (STM32F0 Cortex-M0 at 48MHz), unlike BLHeli and BLHeli_S ESC’s that runs on 8-bit processors. BLHeli_32 does not work with 8bit Atmel or Silabs ESC’s.

Benefits of BLHeli_32 Firmware on 32-bit ESC

The 32bit processor on BLHeli_32 ESC has faster clock speed than the 8bit processors in BLHeli_S ESC’s. But BLHeli_S has already set the bar high for performance, it would be interesting to see how much better BLHeli_32 is than BLHeli_S.

With the increased in processing power, faster input signals with lower latency and higher update rate would be possible in BLHeli_32, such as Dshot1200 or even faster protocols! (Read about DShot)

The most exciting news about the 32-bit platform is the possibility of future functionality and features that simply wasn’t possible on 8bit ESC’s, such as

  • programmable PWM frequency of up to 48KHz
  • Auto-timing for higher efficiency and realiability
  • Current limiting (with built-in current sensor on ESC)
  • Adjustable “Brake on Stop” force
  • Improve direction change in Bidirectional mode
  • ESC Telemetry
  • Configuring from FC using DShot commands

Note that these features are just ideas from the developer (aka sskaug) at the moment and haven’t all been implemented yet. Some of these sound familiar from the KISS 24A ESC’s. Anyway we should discover more about the new possibility as development continues.

Some Changes From Previous Firmware

The previous BLHeli and BLHeli_S are open source, however the developers have decided to close source the new 32bit firmware. Their names might maintain the same prefix, but we were told BLHeli_32 has been created from scratch. (BLHeli and _S are both Assembly based while BLHeli_32 is C based) ESC manufacturers will have to pay BLHeli developers a licence fee directly to use their 32bit firmware, therefore expect some increase in ESC price.

When asked why the project has become close-source, sskaug replied:

From starting as a personal project to make my mCPX helicopter brushless, BLHeli as come a long way. Some of the major milestones were when we decided to pursue the multirotor segment as well, still as a hobby project, where people flashed various (non BLHeli) ESCs with BLHeli FW. Still moderate activity and efforts. But then at some point, probably starting with the Littlebee, manufacturers started making dedicated ESCs for BLHeli FW. Which I think was a major step forward for the community, as now we have a plethora of very good ESCs for multicopters. Then there was a new milestone where we decided to pursue BLHeli_S, as smoothness of BLHeli was still inferior to other ESCs in the market. And by this time we had close to 20 manufacturers doing BLHeli_S! Supporting which is actually a significant workload.

So then came the next milestone – what was next? ARM 32bit MCUs were a pretty obvious choice, as they are flooding the market from various manufacturers and are getting quite cheap. But at least for me, I was at a point where I did not want to undertake the workload I knew would come without some returns. So this is where we are now, closed source with a modest fee for some returns on the work we actually do. While still supporting many manufacturers and keeping the generally low cost profile of BLHeli.

Hopefully BLHeli_32 will also serve the community well, and bring ESC performance and the hobby as a whole even some more steps forward.

One thing remains the same is using BLHeliSuite for flashing and configuring ESC’s, which is known to be incompatible with Mac and Linux but only Windows. BLHeli Configurator Chrome App was created to tackle this issue by third party developer Andrey Mironov,. But we found out that it won’t support BLHeli_32 since it’s close-source.

Here is how to connect to BLHeliSuite32 via FC passthrough.

BLHeli_32 BLHeliSuite configurator for 32-bit ESC

BLHeliSuite will require an internet connection in order to flash/update firmware and configure settings, that probably means you can’t do it at the field easily. The serial number of the ESC has to be validated at the manufacturers, this is to prevent clones or illegal use of their firmware.

ESC’s that run BLHeli_32

Here I try to gather a list of ESC’s that support BLHeli_32.

In order to run BLHeli_32 firmware, the ESC must be designed specifically for BLHeli_32 according to the developers. That means 32bit ESC’s that already existed before the firmware was released won’t be able to run BLHeli_32. Also note that some other 32-bit ESC might not support BLHeli_32 but their own factory firmware, so make sure you check before purchasing.

First ESC that runs BLHeli_32 firmware Airbot Wraith32

Some 32-bit ESC recently came out don’t necessary are running BLheli-32 firmware but their own, so be aware.


10 thoughts on “BLHeli_32 ESC Firmware Overview

  1. Mateusz

    Going commercial is the moment when greed wins. Every project is an effort, but some people are willing to resign from own benefits and the net value of that is always an advancing product which everyone can improve. Imagine flight-software being commercial. Anyway, BL_Heli32 is NOT the first attempt to bring 32 esc software into market, not only KISS32 tried that but there were ESCs with arm mcu’s long before blheli_s existed. They all never reached such interest as blheli_s, but they all also have common factors either price or closed source. Having said that, making software for ESC on stm32f0 is not that difficult compared to assembly. So that’s why serial key will be needed to prevent open-source competition from implementing trivially simple software so BLHeli can get money for not so new thing ?

    1. boli

      The guy have been devoting his time to provite quality software for the community, and drone racing wouldn’t be there without him.

      People have to eat, pay their bills, heck, become milionnaire. I don’t care. He worked years for that, so if today he wants to cash out, good for him.

      When SimonK was charging a licensing fee back in the day for less than reliable software, it wasn’t that much drama …

  2. Felix

    How can I flash thoose, I’ve heard they won’t support flashing over Fc from the beginning?
    Well not flashing but more configuring.
    Will I have to buy an Arduino or will a Ftdi or hos they’re called adapter work?

    1. Oscar Post author

      I am not sure yet I haven’t received my BLHeli_32 bit ESC and tested them.
      But I assume it should be the same as BLHeli_S in terms of flashing and configuring… only difference is you will have to have internet connection for it to work.

    2. LoWLoW82

      do you have any news about the way to flash this esc because i cant do it through my betaflightF3 FC…


Leave a Reply

Your email address will not be published. Required fields are marked *

Are you Robot? *

I don't look at blog comments very often (maybe once or twice a week), so if you have any questions related to multirotor please post it on this forum You're likely to get a response from me faster on there.