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NordicSemiconductor / pc-ble-driver-py

Python bindings for the ble-driver library
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Application Error response for Write Request not supported #121

Closed sw closed 5 years ago

sw commented 5 years ago

BLE specifies that error codes 0x80 – 0xFF are for vendor-specific application errors. (Core 4.0, Volume 3, Part F, Section 3.4.1.1)

This doesn't work because ble_driver.py tries to cast the value to BLEGattStatusCode when handling BLEEvtID.gattc_evt_write_rsp. That enum does not define the values in the above range.

I'm trying to send error code 0xA1 from a Peripheral, to pc-ble-driver-py acting as Central. I get the following error message: Exception: 417 is not a valid BLEGattStatusCode

417 is 0x1A1, I don't really see where the 0x100 comes from.

This probably also affects the other uses of BLEGattStatusCode such as for Read Response, but I haven't tested those.

alwa-nordic commented 5 years ago

We are looking at a fix for the missing enum values in PR #122.

As for the 0x100, feel free to open a separate issue. But since it is public API, it will most likely be a wontfix or notabug.

sw commented 5 years ago

Thanks for the quick fix @alwa-nordic !

My code is working fine now, though I had to wrap the call to write_req in a try...catch to get the error code. This is because the error codes are caught by the NordicSemiErrorCheck wrapper and not returned from the function, but raise an exception. That probably makes sense for the common case where you don't expect an error.

To anyone looking at this, the offset of 0x100 simply comes from the definition of BLE_GATT_STATUS_ATTERR_.. codes in the softdevice.