Small Espruino thingy that allows for bidirectional serial communication while also detecting Espruino IDE for development

espruino-serial-mixed-mode.js

// Start init
console.log('Preparing JS environment...');

console.log('Booting I2c...');
I2C1.setup({scl:NodeMCU.D1, sda:NodeMCU.D2});

// Command object
var COMMANDS = {};

// Response
function response (data) {
  Serial1.print(JSON.stringify(data) + '\n');
}

// Error handling
function error (code, data) {
    response({
      error: code,
      data: data,
    });
}

// Creates parser
function parseCommand (data) {  
  // Detects IDE, enables console
  if (data.indexOf('print("<","<<",JSON.stringify(process.env),">>",">")') >= 0) {
    Serial1.print('Serial 1 connected to Espruino IDE\n');
    Serial1.setConsole();
    return;
  }
  
  // Handles serial communication
  Serial1.print('Serial1 > ' + data + '\n');
  
  // Ignores invalid commands
  if (data.indexOf('{') < 0 || data.indexOf('}') < 0) {
    return error('E_INVALID', data);
  }
  
  // Tries converting into JSON
  var json = data.substring(data.indexOf('{'), data.indexOf('}') + 1);
  var jsonData = null;
  try {
    jsonData = JSON.parse(json);
  } catch (e) {
    return error('E_PARSE', json);
  }
  
  // No command provided
  if (!jsonData.cmd) return error('E_NOCMD', jsonData);
  
  // Handles commands
  (COMMANDS[jsonData.cmd] || () => {
    error('E_INVALID_CMD', jsonData);
  })(jsonData);
}

// Creates I2c scanner
function scanI2c( i2c, first, last ) {
   if (typeof first === "undefined") {
        first = 0x03;
    }
    if (typeof (last) === "undefined") {
        last = 0x77;
    }
    print( "     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f" );
    for (var upper = 0; upper < 8; ++upper) {
        var line = upper + "0: ";
        for (var lower = 0; lower < 16; ++lower) {
            var address = (upper << 4) + lower;
            // Skip unwanted addresses
            if ((address < first) || (address > last)) {
                line += "   ";
                continue;
            }
            try {
                i2c.readFrom( address, 1 );
                line += (address + 0x100).toString( 16 ).substr( -2 );
                line += " ";
            } catch (err) {
                line += "-- ";
            }
        }
        print( line );
    }
}

// Boot logic to initialize Serial
function init () {
  // Disconnects IDE from Serial
  console.log('Done! Disconnecting Serial1...');
  Serial2.setConsole();
  
  // Setup Serial buffer
  var serialBuffer = '';
  Serial1.setup(115200);
  Serial1.on('data', (data) => {
    data = data.replace('\r', '\n');
    var parseData = data.split('\n');
    if (data == '\n') {
      parseCommand(serialBuffer);
      serialBuffer = '';
    } else if (parseData.length > 1) {
      serialBuffer += parseData[0];
      parseCommand(serialBuffer);
      serialBuffer = parseData[1];
    } else {
      serialBuffer += data;
    }
  });
  
  // Calls main function
  main();
}

function main () {
  // Do stuff.
}

// Starts preparation
init();