How could Nordic received large byte from phone

RE: How could Nordic received large byte from phone

bjorn-spockeli — Mon, 15 Feb 2016 08:51:17 GMT

Great! Happy to help :) I would appreciate if you could mark the answer as correct by clicking the check-mark in a small circle to the left of the answer. -Bjørn

RE: How could Nordic received large byte from phone

mc — Mon, 15 Feb 2016 08:31:36 GMT

Hi Bjørn,

I was able to integrate the code you gave to my own project and it works. Thank you very much.

-Mc

RE: How could Nordic received large byte from phone

bjorn-spockeli — Mon, 08 Feb 2016 13:57:19 GMT

Hi MC, I apologize for my late reply. I have added a zipped version of SDK v9.0 to the answer, where I have modified the ble_app_hrm example to support long writes. In the example the long characteristic is 40 bytes, but you can modify it to be 120 bytes, just make sure that the QUEUED_WRITE_BUFFER_SIZE is larger than the characteristic by about 30 bytes( due to overhead ). You know where to find me if you have any questions.

RE: How could Nordic received large byte from phone

mc — Mon, 01 Feb 2016 13:55:13 GMT

Hi Bjørn,

Still I can find any data when executing the sd_ble_gatts_value_get() in the BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST{EXEC_WRITE_NOW}.

I found some code in long write github.com/.../ble_app_hrs---LongWrite. This does not follow the MSG sequence but I can get the data in BLE_GATTS_EVT_WRITE.

When trying to update the example HRM code of S310 from the long write examplem, this will follow the MSG but I can't get the data.

Is there anything I miss to configure to get the the data written to nordic chip.

Thanks, mc

RE: How could Nordic received large byte from phone

bjorn-spockeli — Tue, 26 Jan 2016 13:27:31 GMT

Oh, I am sorry, I thought that you wanted the peripheral to either read/write to a characteristic not the other way around. Disregard what I have been writting about sd_ble_gattc_write and sd_ble_gattc_read. It is pretty much as shown in the MSC: When the phone or MCP performs a long write to the characteristic where you want to store the data, you will get the BLE_EVT_USER_MEM_REQUEST event from the SD, to which you reply sd_ble_user_mem_reply(). After replying you will get the BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST{PREP_WRITE_REQ} event, to which you reply using sd_ble_gatts_rw_authorize_reply() . Then you will get the BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST{EXEC_WRITE_NOW} to which you reply sd_ble_gatts_value_set(). The value is now in your Attribute table and can be retrieved using sd_ble_gatts_value_get()

RE: How could Nordic received large byte from phone

mc — Tue, 26 Jan 2016 09:57:38 GMT

Hi Bjorn,

Thank you for following me.

In this stage, I want to read the 120 bytes that the phone or the MCP for windows writes to the Nordic chip. After I press the Write long from MCP I receive the BLE_EVT_USER_MEM_REQUEST and the BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST. Till then, I don't know where to place the sd_ble_gattc_read().

I tried to place it on the BLE_GATTS_OP_PREP_WRITE_REQ and/or the BLE_GATTS_OP_EXEC_WRITE_REQ_NOW under the BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST and MCP will terminate because of BTLE_CONNECTION_TIMEOUT.

Will you please elaborate further on of how I get the data using as what you suggested.

Thanks, -mc

RE: How could Nordic received large byte from phone

bjorn-spockeli — Mon, 25 Jan 2016 13:28:46 GMT

The handle, offset and value passed to sd_ble_gatts_value_set() are identical to those passed during the ATT Prepare Write Request.

However, I think I may have referred you to the wrong function if you want to read the characteristic data from a phone using a nordic chip, you should use sd_ble_gattc_read() instead.

RE: How could Nordic received large byte from phone

mc — Sat, 23 Jan 2016 09:37:10 GMT

Hi Bjorn,

Thanks for the reply.

My problem now is on how to get the data from phone to nordic app. I am bit confused on the the message sequence chart.

If I choose the BLE_GATTS_VLOC_USER, I can see any data on attr_char_value.p_value (I guest it would be there?), and if I choose the BLE_GATTS_VLOC_STACK where could I find the handle, offset and peer values. infocenter.nordicsemi.com/index.jsp

I also tried to set the NULL and user memory block of sd_ble_user_mem_reply but still I am empty handed.

Sorry for the confusion, I am still new on BLE development.

Regards, -mc

RE: How could Nordic received large byte from phone

bjorn-spockeli — Fri, 22 Jan 2016 14:50:43 GMT

You can use long writes to write to characteristics that are larger than 20 bytes, please see this post and the documentation of sd_ble_gattc_write

This Message Sequence Chart(MSG) may also be helpful.

-Bjørn

UPDATE:

Modified version of SDK v9.0 where the ble_app_hrs example has been modified to support long writes to the heart rate measurement characteristic.

nRF51_SDK_v9_0.zip

RE: How could Nordic received large byte from phone

mc — Fri, 22 Jan 2016 11:40:49 GMT

Hi,

I would like to have a follow-up my problem. I was able to configure my code to response to BLE_EVT_USER_MEM_REQUEST and BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST, but still I am not able to get BLE GATT WRITE EVENT.

Will someone give me some idea why.

Thank you very much.

-mc