How to Connect, Flash and Configure BLHeli_S ESCs

by Oscar

In this beginner-friendly tutorial, I’ll guide you through the process of connecting, flashing and configuring BLHeli_S firmware on your ESC.

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BLHeli_S vs BLHeli_32

Keep in mind that there are two distinct BLHeliSuite versions, depending on your ESC type:

  • BLHeli_S
  • BLHeli_32

Before proceeding, it’s crucial to determine which firmware your ESC supports, as they are not cross-compatible. This comprehensive guide explains the differences between these two firmware types:

If you’re working with BLHeli_32 ESCs, refer to this guide instead:

To enable RPM filtering, you’ll need to flash the Bluejay firmware. Check out my separate tutorial on how to accomplish this:

Online Tool: ESC Configurator for Hassle-Free ESC Configuration

For a user-friendly and convenient option, try the online ESC Configurator:

This fantastic tool allows you to flash and configure your BLHeli_S ESC without the need to download any software.

Download Software

However if you can’t access the online tool, you can download the software and install it on your PC.

There are two options,

Both programs allow you to flash firmware and configure your ESCs. Personally, I recommend BLHeli Configurator for its user-friendly interface.

Hardware Connection

  1. To begin, make sure your FC is updated with the latest version of Betaflight
  2. Connect your ESC to the FC (signals and ground), then connect the FC to your computer via a USB cable.
  3. Close Betaflight configurator if it’s open.
  4. Finally, power your ESC with a LiPo battery.

Using ESC-Configurator

Assuming your ESC is already connected to the flight controller in your drone, follow these simple steps to configure and update your ESC.

Connect the USB cable to the flight controller (FC) and plug in the LiPo battery to power the ESC.

In the ESC Configurator, click on “Select Serial Port” and choose the appropriate COM port for your FC. If you’re doing this for the first time, your browser might ask for permission to access the COM port.

Flash Bluejay Esc Configurator Serial Port Com

Click “Connect” to display all the available ESCs.

Flash Bluejay Esc Configurator Connect Read Setup

To update the ESC, select “BLHeli_S” in the Firmware section. There’s no need to change the ESC selection. Choose the latest version from the Version dropdown menu, and then click “Flash All”.

Flash Bluejay Esc Configurator Firmware Target

Using BLHeli Configurator

Select your FC’s COM port and click the Connect button.

BLHeli Configurator

Once connected, you’ll see a blank screen. Now, plug in the battery to power the ESC and click “Read Setup” (bottom right).

You’re now connected to the ESC and can configure its settings. Click “Write Setup” (bottom right) to save changes before disconnecting.

BLHeli Configurator Interface

To update BLHeli firmware, click “Flash All” (bottom right). You’ll be prompted to choose a firmware version. The ESC type should be selected automatically, but if not, you can find it in the previous screen (the name is in the title of each ESC).

Using BLHeliSuite

how to flash blheli_s - select silabs blheli bootloader cleanflight fc pass through

For those who prefer the alternative configurator, BLHeliSuite, follow these steps:

  1. In the menu, choose “SILABS BLHeli Bootloader (Cleanflight)” under “Select Ateml / Silabs Interface” to use FC Passthrough for programming or flashing your ESCs.
  2. Select your FC’s COM port and click “Read Setup” (bottom left). If nothing appears, try clicking “Check” (bottom right).
  3. To update BLHeli_S firmware, click “Flash BLHeli” and a pop-up window will appear, allowing you to choose the firmware version.
  4. Choose the latest firmware and click OK to flash.

how to flash blheli_s - read setup check button old 16.0 revision

how to flash blheli_s - click flash choose latest firmware version

After completing these steps, you should see the updated BLHeli_S revision number.

how to flash blheli_s - finished flashing new version blheli_s firmware 16.1

Edit History

  • Jun 2016 – Article created
  • Jan 2020 – Added instructions for BLHeli Configurator
  • Feb 2023 – Updated Instructions

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Dave 26th August 2023 - 2:46 am

The online tool was by far the least hassle of any ESC configurator I’ve used. Thanks Oscar and thank to the authors of the tool.

Hans 25th July 2023 - 10:52 am

Hi Oscar, thanks so much for sharing all this valuable information, much appreciated.

Is it possible to configure the BLHeli_S ESC’s in Closed Loop Mode using BLHeliSuite? And if so, any hints how to do this?

Oscar 26th July 2023 - 2:22 pm

A quick google reveals that the BLHeli_S developers didn’t add Closed Loop mode in both BLHeli_S and BLHeli_32 due to the lack of demand for multirotors (since these two firmware are designed primarily for multirotors)

CC Cagley 5th April 2023 - 11:25 pm

Apparently, the online Bluejay esc configurator is not working at this time (~a week).

What other program cam I use???

Oscar 6th April 2023 - 1:11 am

it’s working for me. I just flashed an ESC last night.

Peter Tiong 9th July 2023 - 3:03 am

Hi Oscar , may I know what is the issue , while I fly , the camera goggle feel a bit vabration , motor and camera mounting had check no problem , pls help thanks

Jesse 23rd March 2023 - 1:35 am

Hey Oscar the beta FPV 12 amp v 2.2 brushless 1s2S flight controller the stock board comes and it says 255 is not supported do you have any idea what that is The motors try to spin but really don’t do a very good job and this is my fourth board and I don’t know what to do so if you can hit me up..thanks bud…..

Robert 13th August 2022 - 4:17 pm

Your site is very helpful, thanks for all you do.

Martin 13th October 2021 - 3:29 pm

i have just resource remapped esc number 2 in betaflight changed the cli command but getting the calibration notes on start up with lipo? motor also doesnt show in blheli and goes too full throttle. All motors will spin in betaflight but no boot seaquance beeps going to motor 4 for some reason? Any help would be greatly appreciated as I am stumped with it. motors will arm after it plays calibration tone

Jake Cauthen 7th May 2021 - 2:51 am

If I donate to your Patreon will you stop deleting my question and answer it.

Oscar 7th May 2021 - 1:44 pm

Nobody is deleting your questions.
All comments are held for approval before becoming public.

Jake Cauthen 7th May 2021 - 2:08 am

I desperately need help with my drone. I replaced one of my BLheli-s ESCs on my drone and it doesn’t want to spin. I’m like 90% sure I need to flash them but I’m not completely sure. Every time I try to connect to BLheli suite it says “please check betaflight revision for support of serial 1 wire passthrough or 4-way interface”. I have looked everywhere and I cannot find anyone that has this issue. Any help would be greatly appreciated.

Oscar 7th May 2021 - 1:43 pm

ESC’s all come with firmware installed, so you don’t have to flash them in order to make them work.
Please try using “BLHeli Configurator”? It’s easier to use, download link in in this guide.

Arthur M Kottcamp 15th December 2021 - 1:27 pm

I have to replace the 4in1 esc on my nazgul 5v2 anolog 6s drone, will it need to be flashed before it will work?

Zeus 2nd May 2021 - 9:19 pm

So I’m wondering if this can be reversed I was updating my esc’s on blheli configurator it froze during the update I messed up and I unplugged it prematurely and now three out of the four esc’s instead of showing sh70 and so forth it just says yyyy Instead.
I’ve tried refreshing it on via healthy configurator but it won’t let me.
Can anyone help?
I have some pictures

Eduard 26th March 2021 - 5:51 am

Hi, Oscar.
I’ve have a (holybro tekko32 f3 metal esc 65a). Is it possible to calibrate it without the FC and without flashing the firmware into it. Right now I try sending 1000-2000us pwms to it and it doesn’t do anything to the motor. Thanks.

Zane Shaw 25th March 2021 - 9:56 pm

Hello, how do you load your previous saved settings.

Oscar 25th March 2021 - 11:01 pm

the program should ask you after updating firmware, whether you want to apply the previous settings or not?

Zlo 5th February 2021 - 8:56 am

Hi Oscar,

I tried the pass through on my Pixracer r14 with both blheli configurator and the suite, but I had not success. I suppose it’s because it’s not running betaflight and it cannot I can imagine.
Do you have a recommandation for a cheap FC running betaflight in order to flash the ESC? Or should I go for the “one wire” option in my case?
Thank you very muc, your blog is pure gold for all us!


Oscar 7th February 2021 - 10:33 pm

This is the cheapest I can find:
You can use it to program/flash ESC’s.
I think you should go with an FC, it’s easier.

Steven Ma 25th September 2020 - 5:15 pm

I recently purchased 4 BLHeli_S ESC. When I flashed it, the PPM (instead of PWM) alway come out. The control board has the print of PWM (not PPM) shown. The motor used is a PWM motor and was got burned during setup. I want to know if the PPM flashed ESC can be used with the PWM control board? If not, what control board should I utilize? Thanks

Juan Gonzalez 10th July 2020 - 3:45 am

Thank you Oscar! The BLHeliSuite worked for me! I thought my FC was damaged when it was failing to flash with BLHeli Configurator.

Max 9th July 2020 - 2:08 am

Hi Oscar,

Great article explaining how to set up escs. I recently installed the mamba f405 mk2 stack with the f50 esc. I completed the build and went to set up the esc just like i usually do. I connected and pressed read setup and then nothing. It said finished reading setup as usual but the screen stayed blank. I have asked many other people about this issue and no one can tell me what is wrong with it. So if you could please try to help me with this problem that would be much appreciated. Thank you.

Oscar 12th July 2020 - 11:02 pm

those are BLHeli_32 ESC, you need BLHeliSuite_32 for those, NOT BLHeliSuite.

Quynn Bell 12th November 2019 - 4:04 pm

I am kinda new to the drone community. I am currently trying to flash my Makerfire 35A BLHeli_S ESC’s. I cannot get BLHeli configurator to flash any other software besides J-H-20. I am able to load almost all versions of J-H-20. I also see other ESC types like G-H-30, but I cannot load any of these. Also, what do the different types and models mean? Does anyone know? There is little to no information online.

My current set up is using the Makerfire 35A Esc’s, SP Racing F3 flight controller and Taranis Q X7 controller. My issue is that the motors do not spin up the same and sometimes reset mid flight. Anyone experience a similar problem? Also, the trottle response is almost none, once I give it one click of throttle the motors spool up to full speed and do not register a drop in throttle from the controller. Is this a software issue or a bad esc? I am willing to provide more information to anyone willing to help. Thanks.

YASH PANDYA 20th August 2019 - 6:52 am

As there is no option for disabling damped light mode, How can we disable it?

Oscar 29th August 2019 - 11:12 pm

you can’t with BLHeli_S firmware

Luis 16th March 2019 - 3:20 am

I have a NiDiCi 30A “BLHeli_32” ESC and I am trying to flash the BLHeli_S firmware on it. The reason being is that my FC is a pixhawk 4 and it only takes analog input but the ESC I currently have uses digital input.
Is there a way this can be accomplished?

Richard L Doberstein 31st January 2019 - 1:16 am

I don’t think this is correct. You cannot flash Blheli_S esc’s with regular BlheliSuite. You will flash it with non S firmware. They have the same names. But it won’t say BLHeli_S anymore after you flash it. You have to use the BLHeli Chrome app, or use the portable version Found here

Jack 17th January 2019 - 8:56 am

I have a problem about my esc. BLheli show firmware code of motor 1,2,3 are ESC A-H-25, 16.6 but motor 4 is ESC A-H-15, 16.6 and I can not Flash it to the same above. I wonder that I use the same ESC of Little Bee 30A-S ESC but it shows not the same firmware code. Can u help me solve this problem?, Thx

George Birchenough 30th November 2018 - 3:07 pm

Hiya. Hoping you can help. I have an application where I need to use a BLDC motor as a starter motor for an engine. I need the ESC to drive the motor immediately when power provided – no arming, beeping, no calibration. Would it be possible to modify the BLHeli code to achieve this? The engine control unit currently opens a relay for 3 seconds to power a brushed motor.

Matyas Csiha 3rd September 2018 - 2:38 am

Hi Oscar,

I’ve got a Racerstar 4 in 1 ESC.

Motor number one isn’t spinning right, even after I switched it out with another one the same thing happens.
That’s why I think something is going on with the ESC. I flashed the firmware on all 4 and still the problem prevailed. Do you have any other ideas what the problem could be? Thank you

Burak 17th August 2017 - 3:27 pm

Hey Oscar, I just looked in these Hex files and they are all like H_L_xxx.hex , L_H_xxx.hex something. I am using Littlebee 20A Pro so what should i choose i dont know can you help me?

Oscar 21st August 2017 - 2:47 pm

You shouldn’t need to choose, BLHeliSuite should detect what ESC you have and decide for you.
If you are having trouble you can also try the BLHeli Configurator (Chrome App)

zsolt sindely 6th June 2017 - 6:15 am

Hey Oscar! It is possible the configure T-motor f45a esc via kiss fc?

Istvan Papp 29th May 2017 - 11:54 pm

Hi Oscar,
There is an Aikon 30A ESC

How can I check which version?
How to connect to Pc?

I use CC3D Rev with openpilot software

Oscar 30th May 2017 - 11:54 am

I don’t use OpenPilot, as far as I know you can:
1. use 1-wire to connected to BLHeli
2. buy a Betaflight controller and use pass through

Vuk 18th May 2017 - 10:00 pm

Hi Oscar,
I have Emax 12A ESC based on BLHeli with NAZE 32 full version. When I connect it to BLHeli Suite and hit connect, the system recognize there are 4 escs but can’t read the type or BLheli firmware version ….. “ESC not found”.
When I hit “check”……. ESC 1 ——-, ESC 2 ———— and so on.
Do you have an idea why it doesn’t work?



Cristian 11th November 2017 - 6:18 pm

Hello friend, I have the same problem, you already could solve it …. ??

matt keenan 4th May 2017 - 6:39 am

1st … is it ok to use an emax 2204 2300kv motor with a (sold as ) hobbypower/ but is really a simonk 30a bec 5/2A dc 5.5v – 12.6v or can it be used on some Racestar BR 2205 ? i dont want to smoke em (esc or motor)!
2nd …is it ok to mix motors like an emax and a racestar if both kv ratings are same ?
finally ..if u have a pre configured known to work simonk 12a esc can you copy the setup on it and put it on all 4 esc so no need to manually setup and calibrate each one seperatly.
thanks tech gods!! ;-D

Oscar 15th May 2017 - 2:06 pm

1. make sure the motor/prop combination draws current under the ESC rating and you should be good to go.
2. don’t mix motors, just the same motors.
3. I don’t use SimonK ESC now, nobody does anymore i think :) so I don’t know !

Mitch 27th December 2016 - 12:47 pm

Hi, just wondering I’ve got aikon SEFM ESCs and running Kiss FC. I don’t want to flash my Kiss FC with betaflight, is there a way to connect the aikon ESCs to my PC to flash them without betaflight passthrough? I had an old AFRO esc usb programmer that I connected but everytime it got to the part to connect and I had to power up my ESC it would just sit there and not recognise my ESC now had power.

Jonno 23rd December 2016 - 9:00 pm

Why doesn’t this have the Input Polarity option? Is it still in development? Or will it never get that feature?

William Mora 30th November 2016 - 1:00 pm

As always, great information and easy to understand. My question is where do I find the information for my esc settings? I have Bl Heli S 30 amp esc with luminier 2206 2450kv motors. I copied settings but would like to make sure everything is correct. Thank you.

Joshua 19th October 2016 - 11:05 pm

What is best to use with Blheli_s, one shot 42, 125, or multiphoton?

Oscar 20th October 2016 - 6:34 pm


Kevin Yang 29th September 2016 - 10:41 am

So If I use this blheli_S firmware, I don’t have to flash multishot firmware again. Is it correct? When I use multishot.

Oscar 3rd October 2016 - 4:03 pm

multishot is part of the BLHeli_S firmware, you don’t have to flash firmware again to use it, it already exisit as an option.

Richard Revell 15th September 2016 - 6:56 pm

Is there any support for the DYS XS30amp ESCs yet as I sure am having a hard time flashing them?

Oscar 19th September 2016 - 3:09 pm

what do you mean by “support” you mean BLHeli_S firmware? try download the latest BLHeli GUI and try again?

Igor 28th July 2016 - 12:00 pm

Can I flash through LUX FC?

Oscar 7th August 2016 - 2:18 pm

yes you can

Jean-Marie 12th July 2016 - 6:06 am

Thanks for this helpful info. Could I ask if ‘unsync pwm’ must be choose with these esc and if yes, which speed (16k,32k..?) (under betaflight configurator GUI) (I’m using seriouslypro Spf3 evo)

Seven5555 27th June 2016 - 12:01 am

Which SimonK firmware should i use on my Multistar 20A V2 ESC With BLHeli and 4A LBEC? All of the info I have found is so old that it doesnt apply

Thank you

Rico 11th June 2016 - 2:54 am

can i use blheli esc(14.4) to configure my setting on the newest blheli software(16.114.6)?

Oscar 13th June 2016 - 3:13 pm

you can use the new GUI (16) to configure older firmware ESC (14.4), but i don’t think you can do it the other way round

Austin Chopra 1st June 2016 - 11:35 pm

Hi Oscar,
What is the deference between blheli vs blheli_s?

FPV Portugal 2nd June 2016 - 9:56 am

hardware pwm in blheli_S, cannot flash blheli escs to blheli_S, its new hardware.

Oscar 5th June 2016 - 9:46 pm

check out this post: BLHeli_S