@parallaxcontrol/node-red-control/cm4-pro-digital-input/cm4-pro-digital-input.js

A comprehensive package of Node-RED nodes designed to seamlessly integrate with the Parallax Control Engine, offering enhanced control capabilities for AV Automation.

const { exec } = require('child_process');

module.exports = function(RED) {
    function Cm4ProDigitalInput(config) {
        RED.nodes.createNode(this, config);
        var node = this;

        // Object to store the last known state of the inputs
        let lastState = { DIN1: null, DIN2: null };

        // Output objects for each pin
        var outputs = {
            DIN1: { Value: false },
            DIN2: { Value: false }
        };

        // Polling function to execute the command
        const pollGpioStatus = () => {
            let command = `/var/www/html/commands/cm4ProDigitalInput.sh`;
            exec(command, (error, stdout, stderr) => {
                if (error) {
                    node.error(`Execution Error: ${stderr}`);
                    node.status({ fill: "red", shape: "ring", text: "Error executing command" });
                    return;
                }

                stdout = stdout.trim();
                var lines = stdout.split('\n');

                lines.forEach(line => {
                    let [pinStatus, status] = line.split(': '); 
                    let pin = pinStatus.trim().split(' ')[0]; // Assumes format "DIN1 Status"
                    let state = status.trim() === '1';

                    //flip the state so that 0 is true and 1 is false
                    state = !state;

                    if (lastState[pin] !== state) {
                        lastState[pin] = state; // Update the last known state
                        outputs[pin].Value = state; // Update the output value

                         // Prepare the message object for each pin
                         if (pin === "DIN1") {
                            node.send([{ payload: outputs[pin] }, null]); // Send only on first output
                        } else if (pin === "DIN2") {
                            node.send([null, { payload: outputs[pin] }]); // Send only on second output
                        }
                    }
                });

                //node.status({ fill: "green", shape: "dot", text: "Output processed successfully" });
            });
        };

        // Start polling at the specified interval (250ms)
        const intervalId = setInterval(pollGpioStatus, 250);

        // Clean up on node close
        node.on('close', function() {
            clearInterval(intervalId); // Stop polling when the node is redeployed or Node-RED is stopped
        });
    }

    RED.nodes.registerType("cm4-pro-digital-input", Cm4ProDigitalInput);
};