ESP32 recording button presses, and serving webpage via webSockets in order to graph the responses. The objective was to test the ESP32 webSocket implementation written in microPython.

To implement, upload firmware.bin to ESP32-dev board

copy all *.py files and *.html/js to ESP32 root directory.

connect two buttons, each with pull up resistors (1 KOhm), on pins 18 and 19

Pin 19 keeps track of fastCountPin, i.o.w. high freq pulses.

Pin 18 keeps track of slowCountPin, i.o.w. low freq pulses (acts like a reset button to Pin 19 counter).

Used : WebSocket libs jczic / MicroWebSrv2

Need to find the website that showed me howto compile ESP32 firmware in Linux Mint (Was not an easy task. Lots of trial and error).

boot.py :	

starts the show Need to enable which Wifi script to run --- AccessPoint or local Wifi network Next enable the pulse_detector.py script, which starts the button press detection

pulse_detector.py

initiates PIN properties, init's webSocket server, increases pin counter, prepares JSON packet and transmits client endpoint
also outputs to terminal: access via screen /dev/ttyUSB0 115200 JSON Packet msgJson = {} msgJson['slowCounter'] = slowCounter msgJson['fastCounter'] = fastCounter msgJson['timeDiff'] = str(time_diff_ms) msgJson['timeDiff_units'] = "ms" msgJson['timeT0'] = str(time_t0) msgArr.append(msgJson)

ws_server.py

serves HTML / CSS and javascript files creates / server endpoints for each js,html, css file

ws_index.html

call JS scripts : moment.min.js ( datetime libs ); Chart.min.js ( Chart libs in HTML5 )

The following snippet creates a webSocket instance. The downside, is that the connection disconnects, but doesn't reconnect, if no activity detected.

        function startingWS ()
        {
            ws = new WebSocket("ws://" + window.location.hostname);

            ws.onopen = function(evt) { 
              console.log("Connection open ..."); 
              ws.send("Hello WebSockets!");
            };

            ws.onmessage = function(evt) {
              console.log( "Received Message: " + evt.data);
              msgJson = JSON.parse(evt.data);
              if(msgJson.slowCounter > counter)
              {
                console.log(msgJson.timeDiff);
              }
              pulses_dataValuesArr.push(msgJson.fastCounter);
              pulses_datalabelStructure.push(counter);

              timing_dataValuesArr.push(msgJson.timeDiff);
              timing_datalabelStructure.push(counter);

            chartPulses.update();
            chartTiming.update();

              counter += 1;
              //
            };

            ws.onclose = function(evt) {
              console.log("Connection closed.");
            };

            ws.closeConn = () => {
                ws.close();
            }
        }