@boarchuz - that code would only get executed AFTER the boot sequence.
The OP was asking about how to keep the pin low DURING boot.
Susan

It probably means that you need to update your library.
I've had some issues where code examples use a newer version of the library and therefore make API calls that are not in my version.
Also the link that you were provided does contain the name 'Latest' in the URL.
Susan

My app scans for BLE servers, connects and reads the characteristic values it is interested in and then sends those to an MQTT hub via WiFi. I'm not doing anything fancy such as turning BLE or WiFI on or off (except to turn both on at the start of the app) but neither am I trying to overlap BLE and ...

I believe there is a parameter in the menuconfig settings for the number of connections - have you checked that?
(I say 'believe' because I've not needed to change it but I do recall seeing it there - I'm not able to check right now.)
Susan

I think I have found the solution. In the ESP_GATTC_SEARCH_RES_EVT, if the service was one I was interested in, I was calling esp_ble_gattc_get_all_char and then remembered the characteristic handle fr later on. In the ESP_GATTC_SEARCH_CMPL_EVT I was reading the queued up characteristic handle and c...

Thank you for your patch which I have just applied. I get the text "Inside esp_ble_gattc_read_char" but nothing after that. Also, what is the point of the call to 'read char' from within the 'write char' function (the 2nd part of the patch)? I'm never calling write char and it does not seem to be ca...

How are you flashing the device?
I was getting this using the QIO method and it was solved by changing to DIO. (This is mentioned at the bottom on one of the documents I found on the web)
Susan

I think it is a bit far off until April Fools day - but that can't be a serious answer! OK - so is what I'm trying to do - call the 'esp_ble_gattc_read_char()' function from the callback routine - the correct way to do this? Is it possible to read multiple characteristics in this way? Are there any ...

The code in that part of the app is: As nothing triggers the 'ESP_ERROR_CHECK' I take it that it is not returning an error.
Susan

1) Yes it is readable
2) No because I've read it from some other devices without bonding
(I wrote the server's code as well so I know how it is configured)
Susan