Expose uhk.sendUsbPacket() and vastly simplify {write,read}-eeprom.js by using it. Make led_pwm.js use uhk.js instead of the obsoleted util.js file.

usb/led_pwm.js

@@ -1,14 +1,13 @@
 #!/usr/bin/env node
-let util = require('./util');
+let uhk = require('./uhk');
 
-let LED_PWM_COMMAND_ID = 10;
-let [endpointIn, endpointOut] = util.getUsbEndpoints();
+let [endpointIn, endpointOut] = uhk.getUsbEndpoints();
 let brightnessPercent = 0;
 
 setInterval(() => {
     brightnessPercent = brightnessPercent ? 0 : 100
     console.log('Sending ', brightnessPercent);
-    endpointOut.transfer(new Buffer([LED_PWM_COMMAND_ID, brightnessPercent]), err => {
+    endpointOut.transfer(new Buffer([uhk.usbCommands.setLedPwm, brightnessPercent]), err => {
         if (err) {
             console.error("USB error: %s", err);
             process.exit(1);
@@ -18,7 +17,7 @@ setInterval(() => {
                 console.error("USB error: %s", err2);
                 process.exit(2);
             }
-            console.log('Received', util.bufferToString(receivedBuffer));
+            console.log('Received', uhk.bufferToString(receivedBuffer));
         })
     });
 }, 500);

usb/read-eeprom.js

@@ -1,19 +1,3 @@
 #!/usr/bin/env node
 let uhk = require('./uhk');
-let [endpointIn, endpointOut] = uhk.getUsbEndpoints();
-
-var payload = new Buffer([uhk.usbCommands.readEeprom, 63, 0x00, 0x00]);
-console.log('Sending ', uhk.bufferToString(payload));
-endpointOut.transfer(payload, function(err) {
-    if (err) {
-        console.error("USB error: %s", err);
-        process.exit(1);
-    }
-    endpointIn.transfer(64, function(err2, receivedBuffer) {
-        if (err2) {
-            console.error("USB error: %s", err2);
-            process.exit(2);
-        }
-        console.log('Received', uhk.bufferToString(receivedBuffer));
-    })
-});
+uhk.sendUsbPacket(new Buffer([uhk.usbCommands.readEeprom, 63, 0x00, 0x00]))

usb/uhk.js

@@ -1,27 +1,63 @@
 let usb = require('usb');
 
-exports = module.exports = {
-    getUsbEndpoints: () => {
-        let vid = 0x16d3;
-        let pid = 0x05ea;
-
-        let device = usb.findByIds(vid, pid);
-        device.open();
-
-        let usbInterface = device.interface(0);
-
-        // https://github.com/tessel/node-usb/issues/147
-        // The function 'isKernelDriverActive' is not available on Windows and not even needed.
-        if (process.platform !== 'win32' && usbInterface.isKernelDriverActive()) {
-            usbInterface.detachKernelDriver();
+function bufferToString(buffer) {
+    let str = '';
+    for (let i = 0; i < buffer.length; i++) {
+        let hex = buffer[i].toString(16) + ' ';
+        if (hex.length <= 2) {
+            hex = '0' + hex;
         }
-        usbInterface.claim();
+        str += hex;
+    };
+    return str;
+}
 
-        let endpointIn = usbInterface.endpoints[0];
-        let endpointOut = usbInterface.endpoints[1];
-        return [endpointIn, endpointOut];
-    },
+let usbEndpoints;
 
+function getUsbEndpoints() {
+    let vid = 0x16d3;
+    let pid = 0x05ea;
+
+    let device = usb.findByIds(vid, pid);
+    device.open();
+
+    let usbInterface = device.interface(0);
+
+    // https://github.com/tessel/node-usb/issues/147
+    // The function 'isKernelDriverActive' is not available on Windows and not even needed.
+    if (process.platform !== 'win32' && usbInterface.isKernelDriverActive()) {
+        usbInterface.detachKernelDriver();
+    }
+    usbInterface.claim();
+
+    let endpointIn = usbInterface.endpoints[0];
+    let endpointOut = usbInterface.endpoints[1];
+    return [endpointIn, endpointOut];
+}
+
+function sendUsbPacket(packet) {
+    console.log('Sending: ', bufferToString(packet));
+
+    let [endpointIn, endpointOut] = usbEndpoints || getUsbEndpoints();
+    endpointOut.transfer(packet, function(err) {
+        if (err) {
+            console.error("USB error: %s", err);
+            process.exit(1);
+        }
+        endpointIn.transfer(64, function(err2, receivedBuffer) {
+            if (err2) {
+                console.error("USB error: %s", err2);
+                process.exit(2);
+            }
+            console.log('Received:', bufferToString(receivedBuffer));
+        })
+    })
+}
+
+exports = module.exports = {
+    bufferToString,
+    getUsbEndpoints,
+    sendUsbPacket,
     usbCommands: {
         getProperty: 0,
         jumpToBootloader: 1,
@@ -35,16 +71,4 @@ exports = module.exports = {
         applyConfig: 9,
         setLedPwm: 10
     },
-
-    bufferToString: buffer => {
-        let str = '';
-        for (let i = 0; i < buffer.length; i++) {
-            let hex = buffer[i].toString(16) + ' ';
-            if (hex.length <= 2) {
-                hex = '0' + hex;
-            }
-            str += hex;
-        };
-        return str;
-    }
 }

usb/write-eeprom.js

@@ -1,6 +1,5 @@
 #!/usr/bin/env node
 let uhk = require('./uhk');
-let [endpointIn, endpointOut] = uhk.getUsbEndpoints();
 var arg = process.argv[2] || '';
 
 if (arg.length === 0) {
@@ -8,18 +7,4 @@ if (arg.length === 0) {
     process.exit(1);
 }
 
-var payload = Buffer.concat([new Buffer([uhk.usbCommands.writeEeprom, arg.length+2, 0x00, 0x00]), new Buffer(arg, 'utf8')]);
-console.log('Sending ', uhk.bufferToString(payload));
-endpointOut.transfer(payload, function(err) {
-    if (err) {
-        console.error("USB error: %s", err);
-        process.exit(1);
-    }
-    endpointIn.transfer(64, function(err2, receivedBuffer) {
-        if (err2) {
-            console.error("USB error: %s", err2);
-            process.exit(2);
-        }
-        console.log('Received', uhk.bufferToString(receivedBuffer));
-    })
-});
+uhk.sendUsbPacket(Buffer.concat([new Buffer([uhk.usbCommands.writeEeprom, arg.length+2, 0x00, 0x00]), new Buffer(arg, 'utf8')]))