# Issues connecting and printing to BLE device **URL:** \ **Category:** BLE / BlueTooth\ **Created:** [December 25, 2023, 1:33am UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704 "2023-12-25T01:33:42Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![steve\_synopsis](https://avatars.discourse-cdn.com/v4/letter/s/48db29/32.png) [@steve\_synopsis](https://community.thunkable.com/u/steve_synopsis)\ **Post date:** [December 25, 2023, 1:33am UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704/1 "2023-12-25T01:33:42Z")
I have a POS terminal with a built-in printer and am having some issues connecting and printing consistently. Firstly, as an FYI, as I posted in another [thread](https://community.thunkable.com/t/trying-to-figure-which-uuids-on-device-to-use/2758219/3), I have found out that the MAC address can be used to connect to the device (@matt_conroy can you get Thunkable to update the documentation to include this please). My app accepts information from the user, retrieves data from a database and then creates an output which I want to print. If I run these blocks in a screen on its own, I can get the printer to connect and print - ![2023-12-24 21 24 05](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/2/d/2df1d8332edbaae45d73a256429d61e5bf42b445.png) However, if I call this screen from another, I either get an error that the device is not connected or that the “Can’t write the characteristic provided.” I would be grateful for any advice. Thanks and Happy Holidays from Barbados, Steve ---
**Author:** ![jared](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/jared/32/138473_2.png) [@jared](https://community.thunkable.com/u/jared)\ **Post date:** [December 25, 2023, 1:48am UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704/2 "2023-12-25T01:48:29Z")
Throw your send message block in the connect blocks then do section ---
**Author:** ![steve\_synopsis](https://avatars.discourse-cdn.com/v4/letter/s/48db29/32.png) [@steve\_synopsis](https://community.thunkable.com/u/steve_synopsis)\ **Post date:** [December 25, 2023, 2:01am UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704/3 "2023-12-25T02:01:39Z")
Hi. This made no difference. Going directly to the connect and print screen works but going through the 4 screens before give me the Can’t write error. ---
**Author:** ![vishruth-ram](https://avatars.discourse-cdn.com/v4/letter/v/82dd89/32.png) [@vishruth-ram](https://community.thunkable.com/u/vishruth-ram)\ **Post date:** [December 25, 2023, 11:20am UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704/4 "2023-12-25T11:20:34Z")
How about removing spaces ---
**Author:** ![steve\_synopsis](https://avatars.discourse-cdn.com/v4/letter/s/48db29/32.png) [@steve\_synopsis](https://community.thunkable.com/u/steve_synopsis)\ **Post date:** [December 25, 2023, 11:52am UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704/5 "2023-12-25T11:52:22Z")
Which spaces? ---
**Author:** ![steve\_synopsis](https://avatars.discourse-cdn.com/v4/letter/s/48db29/32.png) [@steve\_synopsis](https://community.thunkable.com/u/steve_synopsis)\ **Post date:** [December 27, 2023, 9:36pm UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704/6 "2023-12-27T21:36:30Z")
Anyone?? ---
**Author:** ![jared](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/jared/32/138473_2.png) [@jared](https://community.thunkable.com/u/jared)\ **Post date:** [December 27, 2023, 10:23pm UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704/7 "2023-12-27T22:23:14Z")
Sounds like a bug. So: If you have the connection occur on the first screen of the app it works, But. If you add a new screen as the first screen that **only and immediately** redirects you to the screen that connects, the connection fails? Or the write action only fails? ---
**Author:** ![steve\_synopsis](https://avatars.discourse-cdn.com/v4/letter/s/48db29/32.png) [@steve\_synopsis](https://community.thunkable.com/u/steve_synopsis)\ **Post date:** [December 28, 2023, 2:20am UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704/8 "2023-12-28T02:20:00Z")
Sometimes it is the connection, other times the writing. ---
**Author:** ![steve\_synopsis](https://avatars.discourse-cdn.com/v4/letter/s/48db29/32.png) [@steve\_synopsis](https://community.thunkable.com/u/steve_synopsis)\ **Post date:** [December 28, 2023, 10:30pm UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704/9 "2023-12-28T22:30:34Z")
@ioannis @matt_conroy Would you be able to shed some light on this issue? Thanks ---
**Author:** ![matt\_conroy](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/matt_conroy/32/150843_2.png) [@matt\_conroy](https://community.thunkable.com/u/matt_conroy)\ **Post date:** [December 29, 2023, 3:04pm UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704/10 "2023-12-29T15:04:52Z")
Sure, trying to make sure I have it correct. Can you check this app and let me know if it correctly replicates the scenario where you are having this issue? [https://x.thunkable.com/copy/b48bcc58a5324f19cd75a412838bc82d](https://x.thunkable.com/copy/b48bcc58a5324f19cd75a412838bc82d) Screen1: One second delay and then navigate to Screen2 Screen2: Click event to connect to device by device ID. 2nd click event to go to Screen3. Screen3: Transmit string to device. ---
**Author:** ![system](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/0/f/0f59f292712368bce16ff80133ae10de8a6f27e8.png) [@system](https://community.thunkable.com/u/system)\ **Post date:** [March 28, 2024, 3:05pm UTC](https://community.thunkable.com/t/issues-connecting-and-printing-to-ble-device/2759704/11 "2024-03-28T15:05:08Z")
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