This issue was related to how sleep is handled and the clocks get synced. It will be fixed in the next release.

Was this fixed? Can't find anything in the release notes of the last SDKs.

I started to try to use UART polling with DMA for reception like you did when I stumbled upon the post in the link and ran tests to confirm that EMDRV was the cause of my UART problems.  Looks like maybe DMA is not interfered with by EMDRV anymore?

EMDRV implementation of LDMA is not complete (at least it was not at the time I made the original post). So I recommend using emlib library if you want to make a full use of LDMA functionality.

I have the same problem of data getting corrupted while using RX interrupt and BLE together. I am trying to implement using DMA currently. Have u explored any other solution using UART interrupts? I mean by changing priorities or any other way?

No, the LDMA solution worked pretty well for me. The only problem I had was the HardFault exception, when CPU and DMA wanted to access the same RAM region, so I had to implement 2 ping-pong buffers, as described earlier.

Concerning the BLE interrupt priority, it seems that the stack uses Cortex-M4's PendSV core exception on connection events, which has a fixed negative priority and its value cannot be changed as far as I know. So it will preempt any user program interrupt, because interrupt priority cannot be negative.

When you set up custom advertising data with function gecko_cmd_le_gap_bt5_set_adv_data(), you need to start advertising with discover mode "le_gap_user_data":

gecko_cmd_le_gap_start_advertising(0, le_gap_user_data, le_gap_connectable_scannable);

I think in that case you'll have to set up the primary advertising packet as well, including the Flags AdType field. For example:

uint8_t advData[] = {
  // Flags
  0x02, 0x01, 0x06,
  // Complete Local Name
  0x09, 0x09, 'B', 'R', 'D', ':', '0', '0', '0', '0'
};

gecko_cmd_le_gap_bt5_set_adv_data(0, 0, sizeof(advData), advData);

When you set up custom advertising data with function gecko_cmd_le_gap_bt5_set_adv_data(), you need to start advertising with discover mode "le_gap_user_data":

gecko_cmd_le_gap_start_advertising(0, le_gap_user_data, le_gap_connectable_scannable);

When you set up custom advertising data with function gecko_cmd_le_gap_bt5_set_adv_data(), you need to start advertising with discover mode "le_gap_user_data":

gecko_cmd_le_gap_start_advertising(0, le_gap_user_data, le_gap_connectable_scannable);

Actually i thought that i could use descriptors for data exchange.

I am still confused about how exactly to use descriptors since i couldn't find any of the above in my GATT profile.

Descriptors, as the name implies, are used to describe something. In BLE they describe the Characteristic in which they included. For example, you have some custom temperature characteristic in some custom service which has two byte data field. When a GATT client discovers this characteristic, all the information it gets is a 128 bit UUID and two bytes of data, which doesn't tell much about what this characteristic is and how do you interpret its data.

Now if you add Characteristic Presentation Format Descriptor to you Characteristic, it will allow you to describe the format of data field of that Characteristic. For example, you can describe your data as signed 16 bit, so the client will know that those 2 bytes are actually of type int16.

If you add Characteristic User Description Descriptor, you can describe what you characteristic does using plain text. For example, it could say "Temperature, in units of 0.01 degrees Celsius".

So, client, using information provided by these two descriptors, can by himself translate raw Characteristic data into something intelligible. Say, raw data of 0xC4, 0x11 in this example, means 45.48 degrees C.

But you don't really have to use those descriptors. If you develop both client and server devices, you can just program the format of server into a client device.

You can add descriptors either by using GATT Configurator or directly writing into a gatt.xml file. The format is described in UG118.

Actually i thought that i could use descriptors for data exchange.

I am still confused about how exactly to use descriptors since i couldn't find any of the above in my GATT profile.

Descriptors, as the name implies, are used to describe something. In BLE they describe the Characteristic in which they included. For example, you have some custom temperature characteristic in some custom service which has two byte data field. When a GATT client discovers this characteristic, all the information it gets is a 128 bit UUID and two bytes of data, which doesn't tell much about what this characteristic is and how do you interpret its data.

Now if you add Characteristic Presentation Format Descriptor to you Characteristic, it will allow you to describe the format of data field of that Characteristic. For example, you can describe your data as signed 16 bit, so the client will know that those 2 bytes are actually of type int16.

If you add Characteristic User Description Descriptor, you can describe what you characteristic does using plain text. For example, it could say "Temperature, in units of 0.01 degrees Celsius".

So, client, using information provided by these two descriptors, can by himself translate raw Characteristic data into something intelligible. Say, raw data of 0xC4, 0x11 in this example, means 45.48 degrees C.

But you don't really have to use those descriptors. If you develop both client and server devices, you can just program the format of server into a client device.

You can add descriptors either using GATT Configurator or directly writing into a gatt.xml file. The format is described in UG118.