I just tried to flash my Racerstar 20A ESCs with blheliS 16.3, but when trying to read them ESC 3 gave an error (erased or unknown Firmware issue). After flashing ESC 1, 2 and 4, ESC 1 and 3 now gives the same error. I notice there is mentioned a 8k/8k bug in the blheli changelog (https://blhelisuite.wordpress.com/blheli...e-history/) but is there a fix for this?

can you flash them again?
It looks like they have the 30A firmware? is there a 20A firmware? another option is use a previous version. I haven't used Racestar myself but have seen other people flash BLHeli_S on them and worked perfectly

I can't flash them the normal way with pass through anymore. I read at rcgroups that some have successfully recovered them by flashing them with an arduino the old fashioned way, but I can't seem to find the pinout for the racerstar/cicada escs

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There seems to be an issue when running 8k/8k multishot and BLHeliSuite versions lower than 16314702. The bug is that if you don't disconnect the battery before pushing disconnect, something will be written to the ESC causing it to look like it doesn't have any FW. It looks like this only affect people running 8k/8k multishot (I would assume 16k and 32k as well). I Connected mine to a lower version of BLHeliSuite yesterday, and since I did not know about this bug, I didn't disconnect my battery before pushing disconnect. I tried flashing them again with BLHS 16314702, but I can't seem to be able to write to them.

The firmware looks like it is 30A, but it should be correct. This is what comes up automatically when pushing the flash button. I was using G_L_30 16.2 before without any issues, so I would assume it is the correct FW.

It looks like they got the 4 programming pads to hook up an arduino or similar on the underside, are they connected the same on all ESC types?

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I have flashed Eachine Racer ESCs like in this video, and I was thinking that the connection could probably be the same. Then I just have to find the ground with a multimeter on the Racerstars to know what the rest of them is:

I will try to ask Andrey he knows the Silabs chip much better than me

Deducing the pin order for C2 is very easy, there's always a capacitor between GND and VCC pins, and a (2K) resistor between VCC and C2CK. Besides, you can always check which pad is GND with a multimeter.
Hence, in your case:


Attention: Vcc is 3V3 tolerant, don't connect any other voltage to it. You can either power the ESC from your battery for flashing, or provide 3.3V via the Vcc pin. Do not use both at once.
I do not recommend soldering to the pads directly, just use a wire similar to this one:




Algorithm:
1. Connect your arduino via USB
2. Go to BLHeliSuite "Make Interfaces" tab and select correct Arduino Board, select COM port and press "Arduino 4way-interface"
3. Connect the wires according to this document: https://github.com/4712/BLHeliSuite/blob...pinout.pdf
4. Power-up the ESC.
5. Place your programmer pin header over C2-pads
6. Select SILABS C2 (4way-if) and connect via BLHeliSuite, try reading setup

If you need help with a particular Arduino connection, just give us a photo and we'll point where to connect the C2-interface wires.

P.S. BLHeliSuite 16.3.14.7.0.2 indeed fixes the problem. I wonder why Achim wasn't sending the DeviceReset command when it was always there in the protocol. My configurator on the other hand shouldn't be prone to this error as it was always sending DeviceReset on disconnect.

Thanks, I went through the BLHeli Silabs supported ESCs document now, and it looks like every ESC with 4 solder pads next to each other like on the racerstar, littlebee etc has the same pinout, 1= Ground, 2=not used, 3=power, 4=signal. So if I find the ground pad, I should be able to figure out the rest of them

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Sorry, I didn't notice your markup untill now. Are you sure that is correct? If you look at this photo, it is like described for most ESCs in the blheli documentation:



But I will check with a multimeter once I get home. Thanks again!

I've messed the colors, but what you should look at are labels.
C2-interface is always in this order: GND, Vcc, C2CK, C2D. The only thing which may be different is orientation.
Pin 2 is not unused, it's Vcc (3.3V), Pin 3 is not power, but C2CK - clock signal, Pin 4 is C2D - data signal. Don't confuse them with usual servo pinout, they're completely unrelated.

Image with correct colors:

Ok, so in the video posted earlier, he doesn't connect the power from the arduino, but ground, c2ck and c2d? So connecting it that way, I will Need to connect battery power, right?

(09-Sep-2016, 03:44 PM)oyvinla Wrote: Ok, so in the video posted earlier, he doesn't connect the power from the arduino, but ground, c2ck and c2d?  So connecting it that way, I will Need to connect battery power, right?

Yes. I'd rather power from 3.3V which is readily available from Arduino to Vcc, and omit the battery altogether.

Ok, I got confused by the BLHeli documentation. There it said: pad1=black=-, pad2=?, pad3=red=+, pad4=white=signal

Does this look right? 
If ground is pad 1, i connected like this:
I connected ground to the power ground instead of pad 1 (red wire)
pad2 to 3.3V (black wire)
pad3 to middle right on the ICSP port (blue/black wire)
pad4 to the lower right on the ICSP port (white/white wire)

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oh, wait, I mean pad 4 to upper left on the ICSP (white/white wire)

I tried connecting to ESC 1, but i get this error message from BLHeliSuite:



I made an arduino uno interface and chose the PB3PB4v16300.hex like in the video.

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It looks like I fixed it. unsoldered the ESC's and made a 4 pin interface cable like you posted earlier. Now, BLHelisuite found the ESCs right away and I was able to flash them with G_L_30 rev 16.3. It is a bit strange that it is named G_L_30 when they are 20A ESCs, but as long as it works I'm happy. Thanks again Andrey! I was affraid I had to order and wait a couple of weeks for new ESCs, but now they should be working again. Now I just have to test them

Glad you've figured out all the issues.
To clear confusion regarding the BLHeli_S naming conventions, they aren't related to the max current rating.
The first letter is layout code, from A to L currently if I recall correctly, it represents a particular hardware MCU pin assignment used by the ESC. Second letter is either L or H for EFM8BB10 and EFM8BB21 respectively. The number is MOSFET switching delay, if you flash your ESC with inappropriate delay you'll run into short circuit and probably meltdown due to more than one motor phase being active simultaneously.

I find it easier to connect C2 wires to arduino shield headers which are labeled, D11 (C2CK) and D12 (C2D) for Uno as far as I'm concerned. It's easier than figuring out the orientation of ICSP header which I always forget  It's also easier since they are sockets, not pins. No need to use this adapter you've invented on your photo.