Add serial binary communication

[umbynos]

Please check if the PR fulfills these requirements

• The PR has no duplicates (please search among the Pull Requests
  before creating one)
• Tests for the changes have been added (for bug fixes / features)

• What kind of change does this PR introduce?

feature

• What is the current behavior?

no serial binary communication

• What is the new behavior?

serial binary communication have been added back: now you can open a serial with this buffer type by using open <port> <baud> timedraw command, once the socketio connection has been established.
To send binary data you have to base64 encode yourself and use sendraw <port> base64_encoded_binary
Tests have been added:

• test_ws_connection and test_list should work even on the CI

• other tests aim to verify if the communication through the serial works correctly, so you have to run them locally (poetry run pytest test/test_ws.py) with a board connected and the sketch present in test/testdata/SerialEcho/SerialEcho.ino already flashed

• Does this PR introduce a breaking change?

it should not

• Other information:

[umbynos]

I still have to produce some docs

[silvanocerza]

See comments.

[umbynos]

This is the diff I'm taking about, the only difference is the location of the casting. Apart from it they are the same. Removing timedbinary

--- /home/umberto/Nextcloud/8tb/Lavoro/arduino-create-agent/bufferflow_timedraw.go
+++ /home/umberto/Nextcloud/8tb/Lavoro/arduino-create-agent/bufferflow_timedbinary.go
@@ -7,50 +7,50 @@
 	log "github.com/sirupsen/logrus"
 )
 
-type BufferflowTimedRaw struct {
-	port              string
-	output            chan<- []byte
-	input             chan string
-	done              chan bool
-	ticker            *time.Ticker
-	bufferedOutputRaw []byte
-	sPortRaw          string
+type BufferflowTimedBinary struct {
+	port                 string
+	output               chan<- []byte
+	input                chan []byte
+	done                 chan bool
+	ticker               *time.Ticker
+	bufferedOutputBinary []byte
+	sPortBinary          string
 }
 
-func NewBufferflowTimedRaw(port string, output chan<- []byte) *BufferflowTimedRaw {
-	return &BufferflowTimedRaw{
-		port:              port,
-		output:            output,
-		input:             make(chan string),
-		done:              make(chan bool),
-		ticker:            time.NewTicker(16 * time.Millisecond),
-		bufferedOutputRaw: nil,
-		sPortRaw:          "",
+func NewBufferflowTimedBinary(port string, output chan<- []byte) *BufferflowTimedBinary {
+	return &BufferflowTimedBinary{
+		port:                 port,
+		output:               output,
+		input:                make(chan []byte),
+		done:                 make(chan bool),
+		ticker:               time.NewTicker(16 * time.Millisecond),
+		bufferedOutputBinary: nil,
+		sPortBinary:          "",
 	}
 }
 
-func (b *BufferflowTimedRaw) Init() {
-	log.Println("Initting timed buffer raw flow (output once every 16ms)")
+func (b *BufferflowTimedBinary) Init() {
+	log.Println("Initting timed buffer binary flow (output once every 16ms)")
 	go b.consumeInput()
 }
 
-func (b *BufferflowTimedRaw) consumeInput() {
+func (b *BufferflowTimedBinary) consumeInput() {
 Loop:
 	for {
 		select {
 		case data := <-b.input: // use the buffer and append data to it
-			b.bufferedOutputRaw = append(b.bufferedOutputRaw, []byte(data)...)
-			b.sPortRaw = b.port
+			b.bufferedOutputBinary = append(b.bufferedOutputBinary, data...)
+			b.sPortBinary = b.port
 		case <-b.ticker.C: // after 16ms send the buffered output message
-			if b.bufferedOutputRaw != nil {
-				m := SpPortMessageRaw{b.sPortRaw, b.bufferedOutputRaw}
+			if b.bufferedOutputBinary != nil {
+				m := SpPortMessageRaw{b.sPortBinary, b.bufferedOutputBinary}
 				buf, _ := json.Marshal(m)
 				// data is now encoded in base64 format
 				// need a decoder on the other side
 				b.output <- buf
 				// reset the buffer and the port
-				b.bufferedOutputRaw = nil
-				b.sPortRaw = ""
+				b.bufferedOutputBinary = nil
+				b.sPortBinary = ""
 			}
 		case <-b.done:
 			break Loop //this is required, a simple break statement would only exit the innermost switch statement
@@ -59,16 +59,16 @@
 	close(b.input)
 }
 
-func (b *BufferflowTimedRaw) BlockUntilReady(cmd string, id string) (bool, bool) {
+func (b *BufferflowTimedBinary) BlockUntilReady(cmd string, id string) (bool, bool) {
 	//log.Printf("BlockUntilReady() start\n")
 	return true, false
 }
 
-func (b *BufferflowTimedRaw) OnIncomingData(data string) {
-	b.input <- data
+func (b *BufferflowTimedBinary) OnIncomingData(data string) {
+	b.input <- []byte(data)
 }
 
-func (b *BufferflowTimedRaw) Close() {
+func (b *BufferflowTimedBinary) Close() {
 	b.ticker.Stop()
 	b.done <- true
 	close(b.done)

[umbynos]

I prepared a Release Candidate to test the functionality out.

[umbynos]

Documetation have been updated: https://github.com/arduino/arduino-create-agent/wiki/How-to-use-the-agent#receiving-and-sending-data

[cmaglie]

Overall looks good, if you have tested it, it's ok to merge IMHO.

[cmaglie]

As it is, this loop won't go over a malformed UTF8 sequence. If the UTF8 rune is incomplete it will be completed over multiple iterations, but if the UTF8 rune is corrupted the loop won't go past it.

[cmaglie]

BTW I see that it's the same loop as before, so it may be fixed in another PR if needed.