# BLE Bluetooth data cannot be received **URL:** \ **Category:** Questions about Thunkable X\ **Created:** [March 25, 2021, 10:44pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329 "2021-03-25T22:44:09Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 25, 2021, 10:44pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/1 "2021-03-25T22:44:10Z")
I try to use micropython to develop an app to get sensor data, but I can’t receive and send Bluetooth values right now The information sent by my hardware device is JSON encoded. The address is [ujson – JSON encoding and decoding — MicroPython 1.14 documentation](https://docs.micropython.org/en/latest/library/ujson.html) My APP receiving code and sending code ![111](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/c/1/c103c157a543b220ad2c1ff4ae34cf3f19d87d2e.png) ![2222](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/d/2/d24f0d7d9476991e3b764c347c180fc941db31c0.png) ---
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 25, 2021, 10:44pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/2 "2021-03-25T22:44:41Z")
Please forgive my English is not very good ---
**Author:** ![muneer](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/muneer/32/75210_2.png) [@muneer](https://community.thunkable.com/u/muneer)\ **Post date:** [March 26, 2021, 11:23am UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/3 "2021-03-26T11:23:41Z")
The characteristic UUID should be 0000003A-0000-1000-8000-00805F9B34FB You will receive/send data when using this ID. ---
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 27, 2021, 12:25am UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/4 "2021-03-27T00:25:54Z")
Due to the time difference, I just saw your message, but I still can’t receive any information after I changed it ---
**Author:** ![muneer](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/muneer/32/75210_2.png) [@muneer](https://community.thunkable.com/u/muneer)\ **Post date:** [March 27, 2021, 11:02am UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/5 "2021-03-27T11:02:34Z")
What is the error reported by the green error block? ---
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 27, 2021, 5:41pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/6 "2021-03-27T17:41:45Z")
![image](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/b/a/ba3727f1099ce2d58318dc9c39184a4910cc25c3.jpeg) undefined ---
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 27, 2021, 5:42pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/7 "2021-03-27T17:42:29Z")
![image](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/3/b/3b425ca255345bf566143bfac3e3360649ebb069.png) My code ---
**Author:** ![muneer](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/muneer/32/75210_2.png) [@muneer](https://community.thunkable.com/u/muneer)\ **Post date:** [March 27, 2021, 7:00pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/8 "2021-03-27T19:00:04Z")
In your FSRGB Click, set the text to [green error block] not your own text so if there is an error it displays the error message not your own text. ---
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 28, 2021, 6:55pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/9 "2021-03-28T18:55:30Z")
can’t writ the characteristic provided Am I going to change the feature value in my code to the same? ---
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 28, 2021, 6:59pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/10 "2021-03-28T18:59:02Z")
![image](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/5/3/53af98962edb343d8fef16c56b6c6e2f66d662b3.png) If I change the uuid in the code, an error will occur ---
**Author:** ![muneer](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/muneer/32/75210_2.png) [@muneer](https://community.thunkable.com/u/muneer)\ **Post date:** [March 28, 2021, 7:18pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/11 "2021-03-28T19:18:29Z")
Your BLE device is emulating a serial port so use this UUID 00001101-0000-1000-8000-00805f9b34fb ---
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 28, 2021, 7:59pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/12 "2021-03-28T19:59:47Z")
I changed it in the app, and it still got the same error ![image](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/4/a/4a196a81ba63619238fbe06a7e271c4095304b04.png) ---
**Author:** ![muneer](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/muneer/32/75210_2.png) [@muneer](https://community.thunkable.com/u/muneer)\ **Post date:** [March 28, 2021, 8:26pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/13 "2021-03-28T20:26:14Z")
I advise you to try reading data from the device first. If you want to write to the device then you need to try different options. Most of these devices assume hex codes and not ASCII. Another issue which such devices is that if they work in buads then the device will expect a stream of single characters not a one string. So start with reading from the device as it is simpler. ---
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 28, 2021, 9:43pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/14 "2021-03-28T21:43:17Z")
But I can’t receive any messages now ---
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 28, 2021, 9:45pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/15 "2021-03-28T21:45:00Z")
can’t read the characteristic provided ---
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 28, 2021, 9:45pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/16 "2021-03-28T21:45:29Z")
can’t read the characteristic provided This is an error reminder ---
**Author:** ![muneer](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/muneer/32/75210_2.png) [@muneer](https://community.thunkable.com/u/muneer)\ **Post date:** [March 28, 2021, 10:27pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/17 "2021-03-28T22:27:52Z")
Then it might be that this device has its own characteristic UUID which you need to find out and use. Or the device is not yet connected as a Bluetooth device to your mobile. ---
**Author:** ![renhang999](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@renhang999](https://community.thunkable.com/u/renhang999)\ **Post date:** [March 31, 2021, 5:18pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/18 "2021-03-31T17:18:51Z")
![image](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/4/5/45be284ad4c6cf32d70c95bf50ebe05f5a24e551.jpeg) I don’t know if you can see it clearly. Is it because I have a 16-bit string in front of me? ---
**Author:** ![ioannis](https://sea1.discourse-cdn.com/flex015/user_avatar/community.thunkable.com/ioannis/32/146956_2.png) [@ioannis](https://community.thunkable.com/u/ioannis)\ **Post date:** [November 8, 2024, 1:25pm UTC](https://community.thunkable.com/t/ble-bluetooth-data-cannot-be-received/1187329/19 "2024-11-08T13:25:42Z")