serial: make baud rate configurable and return object

This makes the baudrate configurable and makes the opened serial port accessible - so different parts of the test can share and use this single object and avoid conflicts accessing the port. Also adds error handling for when the port can't be opened Change-type: patch Signed-off-by: Ryan Cooke <[email protected]>
balena-os · Aug 22, 2024 · d2f83a6 · d2f83a6
1 parent 04497d8
commit d2f83a6
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Showing 2 changed files with 17 additions and 5 deletions.
diff --git a/lib/features/serial/implementations/ftdi/index.ts b/lib/features/serial/implementations/ftdi/index.ts
@@ -2,12 +2,13 @@ const SerialPort  = require('serialport');
 
 export class Ftdi implements Serial {
     public DEV_SERIAL = '/dev/ttyUSB0' || process.env.DEV_SERIAL;
+    public BAUD_RATE = Number(process.env.BAUD_RATE || 115200);
     public serial : any;
-    constructor(baudRate = 115200){
+    constructor(){
         this.serial = new SerialPort(
             this.DEV_SERIAL,
             {
-                baudRate: baudRate,
+                baudRate: this.BAUD_RATE,
                 autoOpen: false,
             });
 
@@ -18,9 +19,20 @@ export class Ftdi implements Serial {
 
     async open(){
         if(this.serial.isOpen){
-            console.log(`Serial already open!`)
+            console.log(`Serial already open!`);
+            return this.serial;
         } else {
-            this.serial.open();
+            try{
+                console.log(`Opening Serial port ${this.DEV_SERIAL} with baud rate: ${this.BAUD_RATE}`)
+                this.serial.open(() => {
+                    console.log('DUT serial is opened');
+                    this.serial?.flush();
+                })
+                return this.serial;
+            } catch(e){
+                console.log(e)
+            }
+
         }
     }
 

diff --git a/lib/interfaces.d.ts b/lib/interfaces.d.ts
@@ -38,7 +38,7 @@ interface Serial extends Base{
     serial: any;
     write(data: string): Promise<string | void>;
     read(): Promise<string>;
-    open(): Promise<void>;
+    open(): Promise<Stream.Readable | null>;
     close(): Promise<void>;
 }