Htcc-ab02s GPS exampe stops working after some hours

im Using example code and TTN otaa.

I send GPS data to TTN every 30min. The example works fine at first, but after about 5 hours it sends final two messages in less than 1s and then stops for ever.

For me it looks as if the sleep mechanism fails (or rtc problem?)

The problem happens if USB or battery powered or if ADR is enabled or disabled.

Anybody expireinced the same? Any suggestions?

Best Regards

Change the Hardware!

Thats a huge problem. =/

Did u find any reason? I have two boards, both with this problem.

In fact if the interval between payload is 30 s it stops after 5 minuts

My case:

Interval Stops
30 s =~5m
120 s =~20m

Your case

Interval Stops
30m or 1800s 300m or 5 h

It has the same relation. Debugin the code I realize that it stops inside


inside of the while i managed to put some prints in order to check the condition of the millis(). However is a freeze bug, in fact is not running forever…

while(millis() - starttime <1000)

{   Serial.println("Millis: " + String(millis()));

    Serial.println("Start Time: " + String(starttime));

output for some testes:

stops like this:

:54:03.286 -> Millis: 334442
13:54:03.286 -> Start Time: 334173

14:02:29:934 -> Millis: 333596
14:02:29:934 -> Start Time: 333326

This time depends of the interval of uplink in this case was 30 seconds.

Please someone of heltec can help us? @jasonXu

Guys, please. Could u look this?

I solved my problem by switching from Lorawan_App to Lorawan_ Minimal. Since then the app runs without problems for a long time.

Please tell me where I can find Lorawan_Minimal. I could not find it by searching on this site or github.


Sorry, your mail was in my spam filter:
You find it under:

Best regards

i have the same problem and only change #include “Arduino.h” to #include “LoRaWanMinimal_APP.h”
doesn’t help.
What did you exactly change?

I`m using software serial and is working. But I cannot use many function implemented already for hardware serial.

#include "softSerial.h"
#include "CubeCell_TinyGPS++.h"

TinyGPSPlus gps;
softSerial  ss(UART_TX2 /*TX pin*/, UART_RX2 /*RX pin*/);

@heltec @heltec369

Guys from heltec you should fix it or provide a nice library using software serial. We need at least a feedback about this.

1 Like

@heltec @heltec369
… please fix this problem!

@heltec @heltec369

Did anybody get this to work? I’m having the same problem with an AB02s V1.0 and V1.1 onboard gps on cubecell version 1.3.0 and 1.4.0. The device always gets stuck between 5 and 13 gps iterations after the message “GPS current baudrate detecting…”. There is also a GitHub issue #230 about this problem.

It seems, that Heltec isn’t interested to find a solution for this problem!
They earned more money when selling new boards…

@Supporter @heltec
Is there maybe a way to disable the GPS baud rate detection on the AB02s on cube cell version 1.4.0? I’m just guessing but it seems since the function for setting the UART speed came with cube cell version 1.3.0 it created the crash after couple GPS iterations.

… in the new CubeCell Version 1.5.0 no change, same problem!

We will fix this problem as soon as possible.

Who is we?
As soon as possible? This problem exists since 1 year!
The htcc-ab02s is with this problem for me unusable…

1 Like

I did not just include MinimalLora (in my Program, not in Arduino.h), I coded my program like a minimal lora example.

Hi Folks.

Can anyone explain in detail how to get this sketch to work permanently?