Here I explain how to flash/update BLHeli_S firmware on your ESC using Cleanflight FC Pass-through.
At the moment BLHeli_S is only supported on a very limited number of ESC’s (as far as I know, the Aikon SEMF 30A, DYS XS20A and EMAX Lightening 35A). You should check out this guide about how to choose ESC.
They all come with BLHeli_S pre-flashed, so when you connect them to BLHeliSuite you should see that. Flashing with one-wire or FC pass-through should both work fine. Here I demonstrate how to update BLHeli_S on my new Aikon SEFM 30A ESC with cleanflight FC pass-through.
Hardware and Connection
- First of all, flash Betaflight on your FC in order to use the FC pass through feature
- Plug your ESC signal/ground cable into the FC motor output pins (I used PWM #1 here)
- Connect the FC to computer via USB cable, but do NOT connect to Cleanflight GUI
- Power on the ESC with LiPo, 3S, 4S doesn’t matter as long as rating allows
Firmware and Software
5. Download the latest BLHeliSuite software from here (link in the section at the very bottom, read me)
6. Under “Select Ateml / Silabs Interface” in the menu, choose “SILABS BLHeli Bootloader (Cleanflight)” to use FC Passthrough to program/flash your ESC’s
7. Select the correct COM port of your FC, and press “read setup”. If nothing shows up you might need to press “check” as well.
8. The interface is different from the normal BLHeli with reduced options.
9. If you see “BLHeli_S Revision” number is below the latest version, then you need to update it. (The latest was 16.1 at the time)
10. Press “Flash BLHeli” and you will see a pop up window. firmware option should be filtered down to only 1 left, because it has BLHeli_S installed previously, and the system can detect what ESC this is connected.
11. Select this firmware, and click OK to flash.
After it’s done, you should see the Revision number updated.