Comments for Gil's Development Journal

Comment on Speed Challange: MineSweeper – Postmorterm by Ran Argaman

Ran Argaman — Tue, 17 May 2011 06:47:39 +0000

Nice one!

Comment on Serial Port Hell by Gil

Gil — Thu, 12 May 2011 21:27:54 +0000

I made sure to read two bytes every time.
also, it’s easy to re-sync: clear the recieve buffer

Comment on Serial Port Hell by Chris

Chris — Thu, 12 May 2011 19:29:51 +0000

Thanks for the reply.

I was in the process of creating another readbuffer for the parity bytes, but it sounds like your way is easier. Have you had any trouble syncing your app between the data bits and the parity bits? It seems like it will work as long as you always read even byte increments.

I will give it a try and let you know how it works. Thanks again.

Comment on Serial Port Hell by Gil

Gil — Thu, 12 May 2011 14:46:56 +0000

Actually, the solution is inside isr.c !

Search for SerialPutChar(…) which puts a character into the recieve buffer.

You’ll have to change in two locations: first is where no error occurred and the second is where a parity error has occurred.
for each of them add another call to SerialPutChar(…), this time with the parity information.

Make sure NOT to change other calls to SerialPutChar(…) since they are crucial to reading the buffer properly.
Also take into account the current Parity settings, since an error with the PARITY_SPACE means parity bit = 1 and an error with the PARITY_MARK means parity bit = 0. This brings ReadFile() an extra byte with parity for each read byte.

let me know how it worked out for you

Comment on Serial Port Hell by Chris

Chris — Tue, 10 May 2011 23:53:02 +0000

I am having the same exact issue and have resorted to the WinDDK as well. Just curious how you finally ended up reporting the parity information back from the driver. Did you have to create a custom IOCTL or were you able to somehow get the information from ReadFile? Thanks