# BC127 BLE Writing to Characteristic

**URL:** <https://forum.sierrawireless.com/t/bc127-ble-writing-to-characteristic/12706>\
**Category:** WiFi and Bluetooth Modules\
**Created:** [May 22, 2018, 6:13pm UTC](https://forum.sierrawireless.com/t/bc127-ble-writing-to-characteristic/12706 "2018-05-22T18:13:33Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![zrivard1](https://avatars.discourse-cdn.com/v4/letter/z/5daacb/32.png) [@zrivard1](https://forum.sierrawireless.com/u/zrivard1)\
**Post date:** [May 22, 2018, 6:13pm UTC](https://forum.sierrawireless.com/t/bc127-ble-writing-to-characteristic/12706/1 "2018-05-22T18:13:33Z")

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I have been working with two of your BC127 development boards in hopes of adding BLE support to a current project when I ran into an issue duplicating some of the expected behaviour.

In the provided Melody Audio User Guide, on page 72, the following command sequence was issued:  
BLE\_WRITE 14 0028 5  
\>PENDING  
{48}{45}{4C}{4C}{4F} // values sent in hex format, 5 bytes  
\>OK

Yet when I attempt to execute the above command, the output on the peripheral device is as follows:  
RECV 14 5 {48}{

I have been able to get all of the values across the BLE link by using  
BLE\_WRITE 0028 14  
which will yield  
RECV 20 {48}{45}{4C}{4C}{4F}  
(Minor note: the 14 in the BLE\_WRITE is read as a hex value while the 20 in the RECV is decimal.)

In either case, I have not been able to successfully write to any BLE characteristics, and I was hoping to get some clarification as to how I would be able to write to characteristics.

-The Melody version that I am using is  
Melody Audio V7.1 RC1 SCOTT  
Build: 1525368088

Thanks,  
Zach

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**Author:** ![mlw](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/mlw/32/3706_2.png) [@mlw](https://forum.sierrawireless.com/u/mlw)\
**Post date:** [May 23, 2018, 1:39pm UTC](https://forum.sierrawireless.com/t/bc127-ble-writing-to-characteristic/12706/2 "2018-05-23T13:39:46Z")

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Zach,

Can you give all of theset up information as well so that it can seen how you are setting up characteristic 28, also, why not just use send ?

Regards

Matt

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**Author:** ![zrivard1](https://avatars.discourse-cdn.com/v4/letter/z/5daacb/32.png) [@zrivard1](https://forum.sierrawireless.com/u/zrivard1)\
**Post date:** [May 23, 2018, 3:13pm UTC](https://forum.sierrawireless.com/t/bc127-ble-writing-to-characteristic/12706/3 "2018-05-23T15:13:01Z")

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Matt,

Thank you for your reply. I was actually just able to solve my problem - turns out it is just a formatting issue.

When sending the byte data, the `{<value>}` format sends as an string and not as raw byte data. In order to send the byte with value 0x48, you must send the character ‘H’.

Thanks again for your time,  
Zach