[PD] Comport issue: two digits problem

martin.peach at sympatico.ca martin.peach at sympatico.ca
Thu Dec 10 19:36:14 CET 2009

lineacurva wrote:

> Hi guys,
> I'm working on my first RFID project, involving Arduino and Pure  
> Data. I use Innovation Id-20 reader and Arduino 2009. I'm stuck in a  
> problem with "comport".
> As I put a transponder near the reader, in Arduino serial monitor I  
> can see a number like: 495211712056
> But in the little patch I attach here, comport reads: 53
> This is a problem since more than one transponder give me a "53"  
> feedback (but a different 12 digits number in Arduino monitor).

53 is the ASCII value of the character '5'. Probably if you add a [print] to the [comport] output you would get a list of 12 ASCII values for each sample.

In Pd you need to accumulate the list of incoming ASCII codes, subtract 48 (ASCII '0') from each, and route them accordingly. A 12-digit number won't display correctly as a float. Probably it's easier in Arduino to make your numbers ints on [0..255] and send them as BYTE. Then you get one number per sample and don't need to handle lists.


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