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.
Check out this article to learn about ESC firmware.
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.
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, including
- 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
48KHz PWM frequency and Auto motor timing have been reported to improve flight performance noticeably.
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.
BLHeli_32 Features and Tutorials
- Play Music with Your ESC and Motors
- Use ESC Beacon as a lost model alarm
- Setup ESC Telemetry in Betaflight
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.
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 support BLHeli_32
Here is a full list of ESC’s for mini quad, you can look up which ones support BLHeli_32 firmware.
|I compiled the specification of all ESC’s for mini quad in this spreadsheet so you can compare them more closely.|
In order to run BLHeli_32 firmware, the ESC must be designed specifically for the firmware. That means 32bit ESC’s that already existed before the firmware was released might not work with BLHeli_32. Also note that some 32-bit ESC’s might only run their own factory firmware, so make sure you check before purchasing.