rs232 to grasshopper

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Permalink Reply by Andy Payne on September 17, 2012 at 6:05pm

Hi Martin,

If you look at your device manager, does the Tag Heuer timing system show up under the ports tab (associated with one of those ports)?  This would be the best way to determine if one of those COM ports belongs to your timing system.  If it doesn't show up with a name, you can try unplugging and re-plugging in the device and see which device registers itself with the device manager. 

I haven't tried communicating with a rs232 device... but in theory the Open Port component should simply connect to any COM port using a given baud rate... so this should work for your application (again, in theory).  I'm curious to see if it works.  Please report back if you don't mind.

Cheers,

Andy

Permalink Reply by Martin Siegrist on September 18, 2012 at 2:38pm

hey Andy, the Tag Heuer device doesn't show up in the device manager but I found out it's on port number 1. I downloaded a trial version of split second timing software and managed to retrieve live data using two pairs of photo cells. 

I attached my grasshopper definition. It doesn't read any data from my Tag Heuer device. The panels don't show anything.... unfortunately....

Attachments:

• 12_09_08_grasshopper_rs_232.PNG, 77 KB
• 12_09_08_split_second_test.PNG, 97 KB

Permalink Reply by Andy Payne on September 18, 2012 at 6:03pm

Well, the good news is that the port opened successfully (based on your image).  It's good that you set the baud rate to 1200, as this seems to be the bit rate that the Tag Heuer software is using as well.  I believe (and I'm not totally sure) that the issue may be because of the 'end of line' marker.  You see, the Generic Serial Read component uses a carriage return ('\r') and new line feed ('\n') to determine the end of the line of data being sent over the serial port.  When it detects these symbols, it outputs all of the data that has been stored in the buffer, and then starts to wait for the next line to come over the port.  I'm wondering if the code running on the rs232 device can be configured to send these characters to indicate the end of each line.

From the image you posted, it looks like the Tag Heuer device is using a 1200/8-N-1 configuration for the serial communication.  Here's a link for more information: http://en.wikipedia.org/wiki/8-N-1.  I'm not sure what the stop bit the device is using, but perhaps this is what could be causing the conflict.  I'm sorry I don't have more answers on exactly how to trouble shoot this problem.

Out of curiosity... Is there a reason you're using this device?  Is it much cheaper than an Arduino?  It sounds like you've only got 2 photocells connected in your circuit.  These cost less than a dollar, and an Arduino will cost you around $30.  And the photocell circuit is very easy to setup using an Arduino/Firefly.  Just curious why you want to use this device. I definitely want to get this rs232 thing figured out... but just wondering if there is an easier way.

HTH,

Andy

Permalink Reply by Martin Siegrist on September 19, 2012 at 12:03am

hey Andy, that's true, the Tag Heuer device is using 1200/8-N-1

I tried to connect it because I have the device and I thought why not give it a try? I almost prefer having the data from my timer come into grasshopper instead of excel so I can create my own visualization for time or speed.

Since I'm not a programmer I have no clue how to change the stop bit of the device. Could that be an option for the grasshopper component?

thanks for your help!