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HELTEC ESP32 LoRa V3 - Starting LoRa failed! msg

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Joined: 3 months ago
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Hello Guys, hope all is well. This is my first post.

I have a 'HELTEC 915 ESP32 LoRa OLED Board V3 Type-C SX1262 + 915MHz LoRa Antenna U.FL IPEX to SMA for Arduino IOT LoraWan Gateway, not Compatible with LoRa 32 V2'.



I am trying to run the sketch that is under 'Demo 1 – Simple Data Transfer' ( )

I exactly copied this sketch on both my boards and uploaded them via my Arduin IDE. It compiled fine.

The probelm is that the Serial monitor on the Arduino IDE keeps telling me that there is an issue.

The Sender's serial monitor says:

(����u#��!�LoRa Sender Test
Starting LoRa failed!

The receiver's serial monitor says:

(��L��DJ�LoRa Receiver Test
Starting LoRa failed!

Those jumbled characters in both serial outputs sometimes mean that there is a Serial communcaiton issue. But, I have checked the baud rates on the sketch and the serial monitor and they are the same.

I feel that my csPin, resetPin, irqPin are not the correct pon numbers.

This is what they say on the sketch:
const int csPin = 4; // LoRa radio chip select
const int resetPin = 2; // LoRa radio reset
const int irqPin = 3; // Must be a hardware interrupt pin

I looked all over the internet and also referred to the schematic below that is provided by Heltec.


I changed my pins to:

const int csPin = 8;     // LoRa radio chip select
const int resetPin = 12;  // LoRa radio reset
const int irqPin = 14;    // Must be a hardware interrupt pin

The problem still persists even after changing the pin numbers. 

I was wondering if someone could give me some feedback. 

Thank you for your reply!

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Father of a miniature Wookie
Joined: 4 years ago
Posts: 7410

@jack2990 The garbled output is quite common until the board is fully initialized.

Another forum user has the same error with a different board. I had a close look and it is caused by the Version Register returning an answer other than 12.

I have a couple boards and get no such errors.

I am in tha midst of an SSS attack so can't do much more. Try to find a suport link and report it there. Show them the code and the error message although if it happens with their sample that would be better.

The Heltec environment is not the cleanest, so things like board name, version are critically important.

Show me the contents of your additional boards manager in case it's something simple.

Changing pin numbers could destroy your board,  be extra careful.

For the sketch you want to use from DBWS, you only need the Lora library, it is the second pic.

NOTE: Remember, Bill is only using a Lora board, NOT a Heltec. His board works with the Library from Sandeep Mistry. HELTEC needs it's own setup so Bills sketch does NOT apply, use the sketches shown in the 3rd and 4th pic.

I enclosed a pic of what my Board environment looks like.

Screenshot 2024 06 08 at 10.23.05
Screenshot 2024 06 08 at 10.25.57
Screenshot 2024 06 08 at 10.30.43
Screenshot 2024 06 08 at 10.30.10


First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.