Custom node require failure


I'm writing a custom node for Node-red (see versions below) but i require other modules/scripts in it.
When i add the require line (see my code) it failes to show up in the node-red brwoser interface. when i comment out the require lines i can see my node.
Ofcorse my node doesn't work as it requires the GPIO package...

What am i doing wrong?

the 'error' code:
26 Jan 12:40:30 - [info] Waiting for missing types to be registered:
26 Jan 12:40:30 - [info] - input-test

My code (JS)

module.exports = function(RED) {

    const CAN = require('mcpreadwrite');
    const SPI = require('spi-device');
	const gpiop = require('rpi-gpio').promise;
	//const gpiop = require('rpi-gpio').promise;

   function INPUTTEST(config) {
		//this.on('input', function(msg) {
		//	this.send(msg);
		gpiop.setup(, gpiop.DIR_IN, gpiop.EDGE_BOTH);
		gpiop.on('change', function(channel, value) {
			msg.payload = value;			
    RED.nodes.registerType("input-test", INPUTTEST);


<script type="text/javascript">
        category: 'US_Input',
        color: '#38F6F6',
        defaults: {
			pin: {value:0}
        icon: "serial.png",
        label: "input-test"

<script type="text/x-red" data-template-name="input-test">
    <div class="form-row">
		<label for="node-input-pin"><i class="icon-tag"></i>Pin</label>
		<input id="node-input-pin">

<script type="text/x-red" data-help-name="input-test">


  "name": "input",
  "version": "1.0.0",
  "description": "Controll the US-Input cart",
  "main": "input.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  "author": "",
  "license": "ISC",
  "dependencies": {
    "mcpreadwrite": "file:../MCP2515-ReadWrite",
    "rpi-gpio": "^2.1.7",
    "spi-device": "^3.1.0"
  "node-red": {
    "nodes": {
      "main": "input.js"

NPM version: 6.14.10
Node.jS version: v12.20.1
Node-Red version: v1.2.6
Running on a RPi 3B+: Linux version 5.4.79-v7+ (dom@buildbot) (gcc version 8.4.0 (Ubuntu/Linaro 8.4.0-3ubuntu1))

Edit reason: added OS

Are the required modules installed?

If you are able to step debug (e.g. in VScode) the put the keyword debugger before the require.

This might help...

Hi steve,

Thanks for your reply.
to the first question: Yes required nodes are installed in the correct place.
I'll have to take a look in the debugger but don't know how it works . (lets find out :slight_smile: )

A more immediate step forward would be to wrap your require() statements in a try/catch block to see what error is actually being reported:

try {
   const CAN = require('mcpreadwrite');
   const SPI = require('spi-device');
   const gpiop = require('rpi-gpio').promise;
} catch(err) {
   throw err;
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