MCP android long write

[bart]

Hi, I'm trying to write a long byte array with the nrf master control panel on android. I'm unsure if the app is able to, but in any case I'm not getting the event: BLE_EVT_USER_MEM_REQUEST. I simply get the BLE_GATTS_EVT_WRITE with BLE_GATTS_OP_WRITE_CMD and the length of the data is cut to 20 bytes.

I can see on the app that char_ext_props.reliable_wr is enabled, furthermore I set:

• cccd_md = BLE_GATTS_VLOC_STACK
• attr_md = BLE_GATTS_VLOC_USER
• max_len = 200

I'm using:

• SDK 6.1
• SD S110 7.0.0
• android 5.1
• master control panel 2.1.1

Does anyone know what i'm doing wrong?

[Hung Bui]

@Bart: I don't think you need char_ext_props.reliable_wr = 1 if you just want long write. Not sure what could be wrong in your case but can you try my example here and let me know the result?

[bart]

Turns out that I had to set char_props.write_wo_resp = 0

[bart]

Thanks for the reply, I checked the code, cause I'm working on linux and I don't know how to use all the settings you include with the project to compile and upload it :) It doesn't include the handling of the write event as far as i could tell.

[Hung Bui]

@bart: We don't add any code in the BLE_GATTS_EVT_WRITE because there is no action needed in the application when receiving a write. If you debug the application you can see it's jump to BLE_EVT_USER_MEM_REQUEST event when you start write long.

[Hung Bui]

@bart: I'm glad that you found the solution. I think the reason for this is that on MCP we will check if the write without response is allowed in the property we will use write command. And this won't allow writing more than 20 bytes. If write without response is not allowed, we will use write request, and this will allow long write.

You can modify your app so that it will use write request regardless the property of the characteristic allow write command.