stopwatch via wifi

MIT App Inventor Help
1

Hi, I am trying to build a stopwatch with an ESP32. Is this possible with the UrsAI2TcpClient? I am getting conflicting information on this and this is what my approach looks like. Unfortunately it doesn't work yet, can you help me?

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2

Hello Sophia

What units of measure will the stop watch use? If seconds, it won't be accurate because time is lost exchanging data. Unfortunately the Clock has low system priority so that only delivers approximate timing too.

I think Anke (App Inventor Power User) made an extension to avoid the issue.

Edit: Take a look at this approach:
https://groups.google.com/g/app-inventor-developers-library/c/6eknWf2cJN0

3

Hi ChrisWard,
thanks for the advise. Actually i have a good enough stopwatch.
I'm afraid my description was not so accurate. I try the following: when a button on the ESP32 is pressed, a signal is sent to the app and the stopwatch starts. So my problem is to send the command "start the clock" to the app with little loss of time. I have a second ESP32 from which the stop signal should come. Unfortunately, it is therefore not possible to use a Bluetooth signal.

4 
[`[Screen1]
Initialize
    → call TCPClient.Connect

[TCPClient]
Connected
    → call TCPClient.SubscribeTopic ("commands/stopwatch")

[tCPClientMessageReceived]
    topic = "commands/stopwatch"
    message = (received message)
    if message = "start"
        → call Clock1.TimerEnabled to true
        // or call your stopwatch component's Start method
    else if message = "stop"
        → call Clock1.TimerEnabled to false
        // or call your stopwatch component's Stop method`
5

It is possible, you just have two Bluetooth components in the App. Bluetooth should generally be faster than WiFi, but of course it all depends on the location and distance in relation to the App.