Unexpected behavior using SW vs. HW SPI on ESP32 with the SX127x LoRa module

Hey 👋,

I'm playing around with the SX127x library in a large project, and have some problems using the HW SPI with the SX127x module.

I've boiled an example down based on the example code.

This works (soft SPI):

// Pins
const PIN_SCK = D5;
const PIN_MISO = D18;
const PIN_MOSI = D23;
const PIN_CS = D19;                               // NSS
const PIN_RESET = D21;

// Configuration
const txConfig = {
    bandwidth: 0,
    freq: 434330000,
    power: 17,
    forcePaBoost: true,
};

// Setup
const spi = new SPI();
spi.setup({ sck: PIN_SCK, miso: PIN_MISO, mosi: PIN_MOSI });
var sx = require("SX127x").connect({ spi: spi, cs: PIN_CS, rst: PIN_RESET });

// Poll DIO0 for interrupts
setInterval(function () { sx.onIRQ(); }, 100);

sx.setTxConfig(txConfig);

// This one uses an interval, to show that it works continuously
setInterval(() => {
  sx.send("Hello", function () {
      console.log("TX done");
  });
}, 500);

But this doesn't (HW SPI, same txConfig, same pins):

// Setup
SPI1.setup({ sck: PIN_SCK, miso: PIN_MISO, mosi: PIN_MOSI });
var sx = require("SX127x").connect({ spi: SPI1, cs: PIN_CS, rst: PIN_RESET });

// Poll DIO0 for interrupts
setInterval(function () { sx.onIRQ(); }, 100);

sx.setTxConfig(txConfig);

// This one is just "locked" in a state of constant transmission (see screen capture)
sx.send("Hello", function () {
    console.log("TX done");
});

My LoRa module is the AI Thinker RA-02.

Anyone have an idea as to why 🙂?

I've attached examples of the captured radio outputs, but I think I've boiled it down to the HW SPI being off in some way, and not setting the radio up properly to begin with.

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