# Looking for help with ESP32 + SX1276 **URL:** \ **Category:** End Devices (Nodes)\ **Created:** [March 30, 2022, 7:10pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185 "2022-03-30T19:10:57Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![bolt\_test](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/bolt_test/32/35697_2.png) [@bolt\_test](https://www.thethingsnetwork.org/forum/u/bolt_test)\ **Post date:** [March 30, 2022, 7:10pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/1 "2022-03-30T19:10:57Z")
Hi ,I am working with the ESP32 and SX1276 module. Uplink is working properly . While doing downlink from the application in things network (Message-\>downlink option in the end node option in App) .The end node is not receiving the data. The end node is flashed with the receive example code from “TheThingsnetwork” Arduino library .The gateway is showing the downlink signal received, But the end node is not receiving it. Please help me with the problem. ---
**Author:** ![Jeff-UK](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/jeff-uk/32/35697_2.png) [@Jeff-UK](https://www.thethingsnetwork.org/forum/u/Jeff-UK)\ **Post date:** [March 30, 2022, 7:28pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/2 "2022-03-30T19:28:11Z")
> [@bolt\_test](#): > > the receive example code from “TheThingsnetwork” Arduino library Which one specifically - the one for the ThingsNode? (An Arduino Leonardo variant with RN2483/2903 Microchip module with onboard LoRaWAN stack)… details/links please. Round here the guys who really seem to know best options recommend something like > **[GitHub - lnlp/LMIC-node: LMIC-node | One example to rule them all....](https://github.com/lnlp/LMIC-node)** > > LMIC-node | One example to rule them all. LMIC-node is an example LoRaWAN application for a node that can be used with The Things Network. It demonstrates how to send uplink messages, how to receive downlink messages, how to implement a downlink command and it provides useful status information. With LMIC-node it is easy to get a working node quickly up and running. LMIC-node supports many popular (LoRa) development boards out of the box. It uses the Arduino framework, the LMIC LoRaWAN library and PlatformIO. Uses well supported library wrapped in one of the best documented and with wide board support - inc ESP32/Sx127x - implementations…though using PlatformIO - It uses the Arduino framework, the LMIC LoRaWAN library and PlatformIO. See also (and earlier parts) > [@Big ESP32 + SX127x topic part 3](https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic-part-3/18436): > > [TTGO%20LoRa32%20V2%20457x376] For previous parts of this topic see: [Big ESP32 / SX127x topic part 1](https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic-part-1/10247)[Big ESP32 + SX127x topic part 2](https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic-part-2/11973) [Last updated: 2021-10-19] The ESP32 microcontroller and SX127x LoRa transceivers The ESP32 has built-in support for Wifi and Bluetooth communication but not for LoRa. A SX127x (or compatible e.g. RFM9x) LoRa transceiver adds support for LoRa and the LoRaWAN protocol that are needed for The Things Network. Semtech SX127x LoRa transceivers and HopeRF RFM9x Lo… ---
**Author:** ![descartes](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/descartes/32/47220_2.png) [@descartes](https://www.thethingsnetwork.org/forum/u/descartes)\ **Post date:** [March 30, 2022, 7:37pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/3 "2022-03-30T19:37:38Z")
> [@bolt\_test](#): > > The end node is flashed with the receive example code from “TheThingsnetwork” Arduino library That code base would only work with the Microchip RN2483 serial modem so it seems very very odd bordering on impossible that that library would drive an SX1276 via SPI on ESP32. Do you have any other libraries loaded? ---
**Author:** ![Jeff-UK](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/jeff-uk/32/35697_2.png) [@Jeff-UK](https://www.thethingsnetwork.org/forum/u/Jeff-UK)\ **Post date:** [March 30, 2022, 7:39pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/4 "2022-03-30T19:39:44Z")
My point exactly! 😉 [https://www.thethingsindustries.com/docs/devices/the-things-uno/](https://www.thethingsindustries.com/docs/devices/the-things-uno/) ---
**Author:** ![bluejedi](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/bluejedi/32/44639_2.png) [@bluejedi](https://www.thethingsnetwork.org/forum/u/bluejedi)\ **Post date:** [March 30, 2022, 7:42pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/5 "2022-03-30T19:42:34Z")
> [@bolt\_test](#): > > Please help me with the problem. To repeat @Jeff-UK, see: [Big ESP32 + SX127x topic part 3](https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic-part-3/18436) ---
**Author:** ![bolt\_test](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/bolt_test/32/35697_2.png) [@bolt\_test](https://www.thethingsnetwork.org/forum/u/bolt_test)\ **Post date:** [March 31, 2022, 10:16am UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/6 "2022-03-31T10:16:43Z")
No, i dont have any other library loaded ---
**Author:** ![bolt\_test](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/bolt_test/32/35697_2.png) [@bolt\_test](https://www.thethingsnetwork.org/forum/u/bolt_test)\ **Post date:** [March 31, 2022, 10:25am UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/7 "2022-03-31T10:25:10Z")
I’m checking with the esp32 ,in arduino ide. could you please help me in the getting downlink data at the end node ---
**Author:** ![bluejedi](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/bluejedi/32/44639_2.png) [@bluejedi](https://www.thethingsnetwork.org/forum/u/bluejedi)\ **Post date:** [March 31, 2022, 11:08am UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/8 "2022-03-31T11:08:45Z")
> [@bolt\_test](#): > > could you please help me in the getting downlink data at the end node He already did: > **[GitHub - lnlp/LMIC-node: LMIC-node | One example to rule them all. LMIC-node...](https://github.com/lnlp/LMIC-node)** > > LMIC-node | One example to rule them all. LMIC-node is an example LoRaWAN application for a node that can be used with The Things Network. It demonstrates how to send uplink messages, how to receiv... If that does not solve your problem then please be more specific in asking your questions. The homework you will have to do yourself: - First check for valuable information already available on the forum (use search!). - Learn the theory about the LoRaWAN protocol and how downlinks work from the LoRaWAN specifications. - Learn about the LoRaWAN library that you (need to) use, which most probably is the MCCI LMIC library (but unclear due to lack of information in your posts). - Follow wise advice (already) given (above). - **Check LMIC-node**! For your information: we don’t have crystall balls so you will have to provide all relevant details about your situation/project yourself. Your OP lacks a ton of details. Please don’t make others have to guess and have to ask for information that you can provide yourself from the start and make your questions more specific. _Forum users are here to help but not for holding hands._ ---
**Author:** ![iijao-balloon](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/i/13edae/32.png) [@iijao-balloon](https://www.thethingsnetwork.org/forum/u/iijao-balloon)\ **Post date:** [January 28, 2026, 11:13am UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/10 "2026-01-28T11:13:17Z")
Hey, this is my first post, don’t know if I’m here right, but I can’t create a new topic and ask because of that here. I tried yesterday to register an ESP32 S3 Cam with SX1276 in TTN, but the OTAA didn’t work. Here information, I hope I mention all relevant. I wanted to use the OAAT example sketch of the MCCI LoRaWAN LMIC Library by IBM, Matthijs Kooijman, Terry Moore, ChaeHee Won, Frank Rose, Tristan Weber. I personalized it, see the uploaded sketch. But it doesn’t work, this is the serial output: ```auto Starting FAILURE /home/david/Arduino/libraries/MCCI_LoRaWAN_LMIC_library/src/hal/hal.cpp:38 Guru Meditation Error: Core 1 panic'ed (Interrupt wdt timeout on CPU1). Core 1 register dump: PC : 0x42002a58 PS : 0x00060d34 A0 : 0x82002a99 A1 : 0x3fcebe60 A2 : 0x3c0302dd A3 : 0x00000026 A4 : 0x3fc984e8 A5 : 0x3fc94990 A6 : 0x00000000 A7 : 0x3fc98190 A8 : 0x82002a58 A9 : 0x3fcebe40 A10 : 0x3fc98190 A11 : 0x00000026 A12 : 0x0000000a A13 : 0x00060523 A14 : 0x00000000 A15 : 0x00000002 SAR : 0x0000000f EXCCAUSE: 0x00000006 EXCVADDR: 0x00000000 LBEG : 0x400556d5 LEND : 0x400556e5 LCOUNT : 0xffffffff Backtrace: 0x42002a55:0x3fcebe60 0x42002a96:0x3fcebe80 0x42002b4d:0x3fcebea0 0x42004e63:0x3fcebec0 0x42004e7a:0x3fcebee0 0x420022ef:0x3fcebf00 0x42008b71:0x3fcebf30 0x4037be1d:0x3fcebf50 Core 0 register dump: PC : 0x40378806 PS : 0x00060334 A0 : 0x8202895c A1 : 0x3fc9f920 A2 : 0x00000000 A3 : 0x00000000 A4 : 0x00060020 A5 : 0x3fc9f1f0 A6 : 0x00000001 A7 : 0x00000160 A8 : 0x8200bdf2 A9 : 0x3fc9f8e0 A10 : 0x00000000 A11 : 0x00000000 A12 : 0x3fc95320 A13 : 0x00000000 A14 : 0x00060020 A15 : 0x3fc9f8ff SAR : 0x00000019 EXCCAUSE: 0x00000006 EXCVADDR: 0x00000000 LBEG : 0x00000000 LEND : 0x00000000 LCOUNT : 0x00000000 Backtrace: 0x40378803:0x3fc9f920 0x42028959:0x3fc9f940 0x4037cf73:0x3fc9f960 0x4037be1d:0x3fc9f980 ELF file SHA256: c61fe3e90 Guru Meditation Error: Core 1 panic'ed (Interrupt wdt timeout on CPU1). Core 1 register dump: PC : 0x403845cf PS : 0x00020434 A0 : 0x82015493 A1 : 0x3fcebcb0 A2 : 0x00020423 A3 : 0xa5a5a5a5 A4 : 0x82015493 A5 : 0x00060425 A6 : 0xfffbfff0 A7 : 0x00000076 A8 : 0x820153b1 A9 : 0x3fcebc80 A10 : 0x00000000 A11 : 0x3fcebc9b A12 : 0x00000001 A13 : 0x3fcebc9c A14 : 0x3fc986b4 A15 : 0x60038000 SAR : 0x00000006 EXCCAUSE: 0x00000006 EXCVADDR: 0x00000000 LBEG : 0x400570e8 LEND : 0x400570f3 LCOUNT : 0x00000000 Backtrace: 0x403845cc:0x3fcebcb0 0x42015490:0x3fcebcc0 0x42028e1d:0x3fcebce0 0x420067f0:0x3fcebd10 0x4200c521:0x3fcebd30 0x40375cb9:0x3fcebd80 0x40375f60:0x3fcebda0 0x00040022:0x3fcebe60 |<-CORRUPTED ``` I’ve connected the board like the following: | ESP32 S3 | SX1276 | | --- | --- | | 2 | DIO0 | | 14 | RESET | | 21 | NSS/CS | | 45 | SCK | | 46 | MISO | | 47 | MOSI | Like written in the Code, I changed the file /Arduino/libraries/MCCI\_LoRaWAN\_LMIC\_library/project\_config/lmic\_project\_config.h, I uploaded it, too. I hope, that is enough information and you could help me. [ttn\_otaa.ino](https://forum.arduino.cc/uploads/short-url/rdrvGYNbTVJors0d5atDkee8oGx.ino) (8,3 KB) [lmic\_project\_config.h](https://forum.arduino.cc/uploads/short-url/kIdNDTfNER49MFJtauS0WhDbbTX.h) (415 Bytes) Thank you, and if somebody is interested about the project (altitude controllable weather balloon), just say, I can write a weekly newsletter or something similiar… PS: I always get update notifications in the arduino IDE for ESP32 boards, but if fails: `Failed to update esp32. Error: 4 DEADLINE_EXCEEDED: context deadline exceeded (Client.Timeout or context cancellation while reading body)` ---
**Author:** ![descartes](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/descartes/32/47220_2.png) [@descartes](https://www.thethingsnetwork.org/forum/u/descartes)\ **Post date:** [January 28, 2026, 12:17pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/11 "2026-01-28T12:17:17Z")
> [@iijao-balloon](#): > > `Interrupt wdt timeout on CPU1` You need to fix this. PS, if you read a bit more of the forum, you’ll then get an automagic upgrade that will allow you to post a new topic. ---
**Author:** ![iijao-balloon](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/i/13edae/32.png) [@iijao-balloon](https://www.thethingsnetwork.org/forum/u/iijao-balloon)\ **Post date:** [January 28, 2026, 3:14pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/12 "2026-01-28T15:14:47Z")
Thanks, but I can’t fix it. I think the problem is, that I use an ESP32 S3 Cam, many pins are needed for the Cam and SD-Card. So I don’t use the default pins. Have you ideas, how to solve that? Here as a complete pinout: | Pin | onboard-part | onboard-function | external part | external function | VCC in V | | --- | --- | --- | --- | --- | --- | | 0 | | BOOT | Servo 1 | | | | 1 | | LED IO2 | GY63 | SCL | 3,3 | | 2 | | | SX1276 | Interrupt-Pin DIO0 | 3,3 | | 3 | | JTAG EN | Servo 2ADC V-in Sensor | | | | 4 | Camera | SIOD | | | | | 5 | Camera | SIOC | | | | | 6 | Camera | VYSNC | | | | | 7 | Camera | HREF | | | | | 8 | Camera | Y4 | | | | | 9 | Camera | Y3 | | | | | 10 | Camera | Y5 | | | | | 11 | Camera | Y2 | | | | | 12 | Camera | Y6 | | | | | 13 | Camera | PCLK | | | | | 14 | | | SX1276 | Reset-Pin | 3,3 | | 15 | Camera | XCLK | | | | | 16 | Camera | Y9 | | | | | 17 | Camera | Y8 | | | | | 18 | Camera | Y7 | | | | | 19 | | USB\_D+ | | | | | 20 | | USB\_D- | | | | | 21 | | | SX1276 | NSS/CS | | | 35 | PSRAM | PSRAM | | | | | 36 | PSRAM | PSRAM | | | | | 37 | PSRAM | PSRAM | | | | | 38 | SD Card | CMD | | | | | 39 | SD Card | CLK | | | | | 40 | SD Card | DATA | | | | | 41 | | MTMS | GPS/SX1276 | RX/DIO1 | 3,3 | | 42 | | MTDI | GPS | TX | | | 43 | TX | LED TX | MOSFET 1 | | | | 44 | RX | LED RX | MOSFET 2 | | | | 45 | | | SX1276 | SPI-SCK (VSPI) | 3,3 | | 46 | | | SX1276 | SPI-MISO | 3,3 | | 47 | | | SX1276 | SPI-MOSI | 3,3 | | 48 | | WS2812 | GY63 | SDA | 3,3 | And I’ve read, that the ESP32 S3 is unstable with the library I use, are there better alternatives? ---
**Author:** ![iijao-balloon](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/i/13edae/32.png) [@iijao-balloon](https://www.thethingsnetwork.org/forum/u/iijao-balloon)\ **Post date:** [January 28, 2026, 3:15pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/13 "2026-01-28T15:15:43Z")
I also tried to connect DIO1 of the SX1276, but that didn’t helped, too. ---
**Author:** ![iijao-balloon](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/i/13edae/32.png) [@iijao-balloon](https://www.thethingsnetwork.org/forum/u/iijao-balloon)\ **Post date:** [January 28, 2026, 4:23pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/14 "2026-01-28T16:23:57Z")
Good news, with the default Pins of the library example, it works! It looks, like I don’t have connection here, I will try tomorrow in the near a relay. PS: I have here lying around a ESP8266 with LoRa EBYTE E220-900T30D, could I build a development relay out of that? ---
**Author:** ![descartes](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/descartes/32/47220_2.png) [@descartes](https://www.thethingsnetwork.org/forum/u/descartes)\ **Post date:** [January 28, 2026, 4:51pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/15 "2026-01-28T16:51:21Z")
> [@iijao-balloon](#): > > could I build a development relay out of that? NO, they are not supported on TTN You should also consider how appropriate it is to use the community network. If you have some scheme for sending pictures, you will breach the fair use policy and the legal limits very quickly. ---
**Author:** ![Jeff-UK](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/jeff-uk/32/35697_2.png) [@Jeff-UK](https://www.thethingsnetwork.org/forum/u/Jeff-UK)\ **Post date:** [January 28, 2026, 5:01pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/16 "2026-01-28T17:01:34Z")
If by > [@iijao-balloon](#): > > I will try tomorrow in the near a relay. You mean near a Gateway! And given > [@iijao-balloon](#): > > could I build a development relay out of that? Again if you mean a Gateway…..then NO! Incorrect use of terms and implied lack of understanding of how LoRaWAN works suggests, as Nick says, you need to read more on the Forum and dive deeper into what LoRaWAN is and how it works and is implemented and what is supported on TTN. In recent times the concept of a LoRaWAN Relay has emerged from the development labs with a specific specification and set of criteria by which they, and any associated end devices, need to be configured and operated but its a bit specialist at this point and good knowledge of standard LoRaWAN (think Min 8 channel) and how that is different to the specific LW Relay (single channel - and definetly not a single channel packet forwarder) implementation should be thought of as key to success with the latter. Others may advise differently but suspect the EBYTE module isnt a good start point for such a project…..a bit like the tourist asking for directions to location XYZ being told by a local “you could but I really wouldnt start from here”! 😁 _update - I note Nick had also replied with same story by time I checked more on the module before I then hit send 🙂_ ---
**Author:** ![descartes](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/descartes/32/47220_2.png) [@descartes](https://www.thethingsnetwork.org/forum/u/descartes)\ **Post date:** [January 28, 2026, 5:13pm UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/17 "2026-01-28T17:13:11Z")
> [@iijao-balloon](#): > > LoRa EBYTE E220-900T30D The core chipset is not LW compatible. And that module is point to point LoRa over a serial port only, so can’t run a LW stack. Possibly useful as a key chain dangly bit. If you want to launch a balloon and send telemetry, perhaps you could ask on one of the HAB forums, as you’d really be better off using a combination of UKHAS LoRa and HorusBinary v2 or the new v3, so you can tap in to the radio amateur network for receiving without any particular limits on how much data you send, unlike LW on TTN. I know this combo works, I can even do it by remote control by using the @stevencellist tele-presence system. Latency can be a bit harsh, but it resulted in a successful flight last week even if the driving was a bit out of the way. My bad, I must learn the road network of other countries. NB: We ONLY discuss LW on TTN/TTI here. Everything else is off topic, so please take the pointers above to do some serious Googling. ---
**Author:** ![LoRaTracker](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/loratracker/32/48502_2.png) [@LoRaTracker](https://www.thethingsnetwork.org/forum/u/LoRaTracker)\ **Post date:** [January 29, 2026, 8:00am UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/18 "2026-01-29T08:00:09Z")
Pins 45 and 46 on the ESP32S3 are strapping pins, you may need to add pullups or pulldowns if you want to use them as GPIOs. ---
**Author:** ![LoRaTracker](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/loratracker/32/48502_2.png) [@LoRaTracker](https://www.thethingsnetwork.org/forum/u/LoRaTracker)\ **Post date:** [January 29, 2026, 8:03am UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/19 "2026-01-29T08:03:48Z")
> [@iijao-balloon](#): > > Thank you, and if somebody is interested about the project (altitude controllable weather balloon), just say, What is the exact nature of this ‘control’ ? TTN\LoRaWAN has significant limitations on the number of ‘control’ packets you can send. ---
**Author:** ![iijao-balloon](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/i/13edae/32.png) [@iijao-balloon](https://www.thethingsnetwork.org/forum/u/iijao-balloon)\ **Post date:** [January 29, 2026, 9:07am UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/20 "2026-01-29T09:07:20Z")
The balloon drops ballast and vents gas to control altitude. But it does that autonomously, we only need to send a downlink, if we want to have it to fly on another altitude. Also, we eventually need to support the balloon with controlling its altitude at sunrise and -set. But that shouldn’t be more than a handful downlinks per day. The balloon should send uplinks every 5 to 15 mins. Pictures would be nice, but if that is against the fair use policy (I will look up how hard we would need to compress a picture) it’s okay. ---
**Author:** ![iijao-balloon](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/i/13edae/32.png) [@iijao-balloon](https://www.thethingsnetwork.org/forum/u/iijao-balloon)\ **Post date:** [January 29, 2026, 9:37am UTC](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185/21 "2026-01-29T09:37:35Z")
> [@Jeff-UK](#): > > You mean near a Gateway! Yes, sorry. But it worked! > [@Jeff-UK](#): > > Again if you mean a Gateway…..then NO! Okay, then it needs to work so. [Next page](https://www.thethingsnetwork.org/forum/t/looking-for-help-with-esp32-sx1276/56185.md?page=2)