Application crash after disconnection

[julienh]

Hi,

I have an application with an accelerometer. This one communicate in I2C (TWI ). The accelerometer send a "data ready" signal every 20ms. I'm using the GPIOTE module to detect this signal and read the acceleration (I2C).

Each time I disconnect the Bluetooth, my application crash. I don't have any information to help me to debug on my app_error_handler. When this error happens, the execution stop at "Unknown funtion 0x000006B0".

1. I tried to disable data ready interuption on the accelerometer and the error disappear (seems to be related to a priority issue with GPIOTE / TWI and SoftDevice).
2. I thought that this issue was realated to a timing issue due to the GPIOTE interuption and TWI read during advertising start so I tried to disable GPIOTE on the data ready input when I have a disconnection event but that doesn't solve the problem.

I already saw another topic about that but the fix is not clear and I don't understand the root cause (devzone.nordicsemi.com/.../).

What I have understood from this topic is that I should use the ble_debug_assert_handler but I don't understand how to link this one with the app_error_handler. Do you have any example?

Any idea to help me to solve this issue? I'm on it since a while ...

Thanks

[julienh]

1. Nothing directly related to the disconnection event but an interruption on the GPIOTE can occur (accelerometer data ready signal) every 20ms. The gpiote interruption handler is really short (just changing a "data_ready" flag to true). Then I'm checking data_ready in the main loop and read the accelerometer value if a new data is available (I2C). Due to the unsynchronized interruption, I tried to disable this when I have the BLE_GAP_EVT_DISCONNECTED event but that doesn't solve the problem.

2. This is what I thought but in fact the TWI is already configured to low level as follow in the sdk_config.c

   TWI_DEFAULT_CONFIG_IRQ_PRIORITY 3

I don't call any SD function from my TWI module neither from a GPIOTE interruption handler or something like that.

3. DEBUG is defined and I'm actually in debugging level 2 and optimization level 1. I tried before other without success. Will try again.