Receive a message from Arduino

MIT App Inventor Help
1

if I receive the message 0, I want the stopwatch to start, and if I receive the message 1, I want the stopwatch to stop. I want it set up so that pressing the button again will toggle the stopwatch to start or stop. I cannot make this code work, please help me."

image
image1261×757 61.7 KB

2

pls help

3

You have to leave the Clock Timer running (enabled), and use the contents of the global msg variable to decide what to do, regardless of whether or not this cycle received anything.

If msg = '0' then add 1 to second.Text
If second.Text >= 60 then 
  add 1 to minute.Text
  set second.Text to 00
If msg = '1' then do nothing.