SIM7000.espruino.js

const PWRKEY = B4;
const TX = B6;
const RX = B7;

// Turn on the SIM7000 module
pinMode(PWRKEY, 'output');
digitalPulse(PWRKEY, 0, 100);

// Set up serial port (UART)
Serial1.setup(115200, {
  tx: TX,
  rx: RX,
  bytesize: 8,
  stopbits: 1,
  parity: null,
  errors: true,
});

// Output received data
Serial1.on('data', (data) => {
  console.log('Received:', data);
});

// Report framing errors
Serial1.on('framing', () => {
  console.log("Framing error!");
});

If I then run Serial1.write('AT\r\n'), I get no data back. Any received data should get picked up by the .on('data') event and logged to the IDE's console.

I also tried using Espruino's standard AT module, with the same result (data is sent, but nothing is received).

Well, at one point there was a flood of framing errors in the serial console:

Framing error!
Received: "\x00"
Framing error!
Received: "\x00"
Framing error!
Received: "\x00"
…

But this went away on its own. Maybe it was caused by a poor cable connection or interference.

Now there's just no response from SIM7000. What could be the cause?