Some errors in FOTA_aws exmaple

Nice to meet you here.
I’m Anatoli Juny. I REALLY need your help.

I’m trying to implement FOTA for my board. It has ESP32 WROOM module.
I followed this tutorial.

Up to step 8, I succeeded. A job is created successfully.

But an error is occurred in the serial monitor and the fota is failed.

I’m not sure what should I do for this.
I REALLY need your help.
Looking forward to hear a good solution from you.
Thanks in advance.


Hi @Anatoli_Juny, can you confirm that you are using the latest Zerynth Studio version (r2.3.2p01)? Some problems in AWS FOTA were fixed in that update.

If you are using the latest version and still having issues I’ll investigate more, thanks.


Hi Antonio.
Nice to meet you here.
Thanks for your reply.

I’m using r2.3.0 version. I don’t think that’s because of the version of Zerynth.
Anyway, I’ll update Zerynth soon and try to test again.
I’ll be in touch with you soon.

Thanks again.

Hi Antonio,

Thanks. I updated the Zerynth with r2.3.2p01 and repeated all the steps in the tutorial.
It worked for the first time. But after that, it doesn’t work anymore.

The following ztc commands were for the first FOTA.

The following ztc commands were for the second FOTA.

For the first FOTA, I used new_firmware_slot_1.json.
For the second FOTA, I used new_firmware_slot_0.json,

I think I’m almost on the approach, but I don’t know how to solve this issue right now.
I REALLY you help.

I hope you will be back to me with a good solution soon.
Thanks in advance.


Hi @a.pitasi

How is it going? Did you check my last messages?
I was waiting for your reply.
I hope you get in touch with me soon.


Hi again, as expected the problem was in the AWS library that we fixed in the latest release.

With your first FOTA you moved from slot 0 to slot 1.

Now, for a new FOTA you need to move back to slot 0: for doing that you have to specify --bc 0 instead of --bc 1 in you link command.

After that the command will work :smile:

Hi Antonio,

Thanks for your help.
That is working perfectly!:+1:

Thanks again.


1 Like

Hi Antonio,
How are you?

I have a question.
Where can I find bytecode-1.vbo file and new_firmware_slot_1.json file?
Are they stored in AWS?

Thanks in advance.

Hey Anatoli,

Those files are generated in the folder where you run the link command, then uploaded to AWS with the next command. You should be able to find your local copy in C:\Users\Jeus according to your screenshots.

Hi @a.pitasi
How are you? I have a question.
I’m trying to upload the firmware to ESP32 board using Raspberry Pi.
My esp32 custom board is connected to RPI via UART(TX/RX).
The code has been completed in zerynth. I want to upload this python code to my board through UART on Raspberry Pi.
Is it possible? In order to do that, I think it is necessary to make the all the python files in the project into one binary file.(like .bin file)
I want to know how can I do it.
Thanks in advance.