Bluetooth Low Energy Transmits but does not Receive

I have made an app that is on a timer to receive incoming data from an HM-10 Bluetooth module every second. However, the spot where the data is supposed to be displayed appears blank. I have tested the module and can get output using a test app, so I am sure that the device is outputting data, however I can not view it in Thunkable. I have also set it up to display the error message when trying to receive data, however the error message appears as undefined.

Hey @dolsen.aspencompress,

What happens if you put the receive block inside the transmit block?

Also, do you have your location sensor enabled?

Finally, are you installing this app onto your phone?


Hello, and thanks for responding. I have tried your suggestions without success.
I am using an Arduino Uno talking to an Android phone via BLE. I have tried both the HC-08 and HM-10 BLE modules. I can connect and send text with both without issue. When receiving with the HC-08 I get an empty box and with the HM-10 gibberish which I will show below.
Arduino code is as follows:

// include the library code:
#include <SoftwareSerial.h>
SoftwareSerial ble(0, 1); //Specify the ports 0 and 1 to be used as the receive and transmit ports for ble
void setup()
Serial.begin(9600); // Open serial port
ble.begin(9600); // begin bluetooth serial port communication
void loop()
Serial.print(“yes”); //Print “yes” to the serial monitor
Serial.print("\n"); //Print "\n to the serial monitor to start a new line
String data = ble.readString(); //Read the string received from the BLE port specified and set the String data equal to this
Serial.println(data); //Print the data received to the serial port

My thunkable app is the attachment

Here is a pic of the gibberish that the HM-10 receives

Thanks for helping!


I see you’re asking about a “Location Sensor.”

I saw this, and can add it to my app if needed. Is it necessary to receive BLE??

Thank you!!

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Bringing this back to the top one more time. It seems from my research that noone in this community has been able to get the BLE receive function to do what it is intended to do.
How unfortunate.
I am developing an app for a portable miniature air conditioner and was really hoping to use this platform as it is so user friendly.
If anyone has had any success at all with the receive function of BLE please chime in.
To the developers, if this is a know issue, please let me know so I can stop beating my head against the wall trying to solve an unsolvable problem.

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Hey @dolsen.aspencompress - nice to talk to you yesterday.

We’re prioritising the issues related to apps crashing right now. Really sorry to keep you waiting on this, but I’ve set a reminder for this so we come back to this on Monday.

@pittsgsal, yeah, my understanding of it was the it’s a BLE requirement rather than a Thunkable requirement. For example, things like bacons need location data to work properly I think.

Thanks for the response.
I look forward to working with you guys to get this sorted out.
Let me know how I can be of any assistance.

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Hi team,

I am using an HM-10 module, communicating via UART\serial pins on an Arduino board, to communicate with the BLE object in an iOS application.

I can use the “Transmit String” successfully, in fact was amazed at how easy this function was to establish.

Unfortunately I’m unable to “Receive String”. I have a label used to trap error messages from the BLE object and it reports no error, and another label to display the returned string from the HM10 and it returns no data.

My thunkable code blocks are below:

Hey @jbacon2014t1 - welcome to the community.

I think this is a known issue. I’m going to move your question to this topic so we can keep track of everything, Hoping to have more information for you about this on Monday.

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Hi @domhnallohanlon,

Thank you for the prompt response and update, much appreciated. I’ll be keenly awaiting your next update post Monday.

@dolsen.aspencompress I reviewed all comparable threads too and couldn’t find a successful use case for the BLE RvcString. This was a little bittersweet - it was good to know I wasn’t alone in investing time (and frustration) with no success and that there is potentially a known defect…however it can be challenging to discover after the fact that there is a known defect and that we should have been investing our IP somewhere else more productive. I’ll be super keen to see absolute clarity provided.

Hey . I am also trying to get a string or byte from a HM-10. I tested the HM-10 operation in the App Inventor environment with their BLE class. everything works great. There it is possible to use the event on the arrival of a string or byte from the device. There is no such item in the BLE class, and you have to use timer intervals (which is not a very good solution). When I send a string from an application to HM-10, the read string event returns the first letter of the sent message to the timer. Strange !!! In fact, the phone modem, when receiving a packet from the radio, sets a flag - there is data from the receiver, there must be a function that monitors this event ???

Got it! Thanks for the response! Really appreciate you guys getting these issues sorted. Can’t wait to get this Bluetooth piece working. When it starts functioning, I’m joining to support you all… :slight_smile:


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Hi @domhnallohanlon,

Is there any update on the BLE Receive functionality?

We have an interested (and increasing) community awaiting progress.

Thank you.

Hoping for any kind of response on this.



Raising this up the flag pole one more time in hopes of some attention.

Any update on this?

I have the same problem with HM10 and with HM19

Hello, sir!

Just following up to see if we’ve made any progress at all with adding some way to interpret data strings and arrays so they don’t just show up as “Undefined” in a Label. I’m certain that it would entail adding some way to call out the string or array as a Hex, Little Endian, Big Endian, Signed or Unsigned, and every other parameter so that the final app can show what is needed.

Anything? Progress??


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@domhnallohanlon any status or plan to communicate?

It is ok if this is not in the priority backlog but I would really need to know what is planned in order to plan the next step of the project I am working on.


I have some problem! Not receive data, no problem transmit.