Parsing serial data from arduino

[gbru316]

I'm trying to read serial data and use it in some logic statements.

The plan is to play audio on RPi when a button is pushed (connected to arduino DIO pins), but at the moment I'm just trying to manipulate the serial data... baby steps

I'm able to read the data with the RPi (print the serial data received) but when I try to analyze it, I get nothing.

Code: Select all

while 1:
     x=ser.readline(2)
     print x
     if x == 25:
          print("pushed")

Shell window displays 25 when the button is pushed, but "pushed" does not display. Conversely, when I set the statement to !=, it says "pushed." I'm guessing it has something to do with data type (binary vs ascii, string vs int, etc)? Anyway, what's the easiest way to implement this?

[stderr]

Code: Select all

     if x == 25:
          print("pushed")

Shell window displays 25 when the button is pushed, but "pushed" does not display. Conversely, when I set the statement to !=, it says "pushed." I'm guessing it has something to do with data type (binary vs ascii, string vs int, etc)? Anyway, what's the easiest way to implement this?

If you say

if x == "25":

doesn't it work?

[PeterO]

If you say
if x == "25":
doesn't it work?

or the other way round should work as well

Code: Select all

if int(x) == 25:

Also might need to watch for problems caused by any white space that may surround the digits in the string.

PeterO

[gbru316]

Found the solution: had to use '25' instead of 25 or "25."

[liudr]

I think your problem is that you used Serial.print instead of Serial.write in your Arduino code. You should have posted that code.