ibutton and interrupt

Jan 23, 2008 2 Replies
J

Hello.



I am developing ibutton reader+MSR(credit card reader) device. It works fine seperately, but when I tried to read card while ibutton is attached, problem happens. I have to detect ibutton attach and detach, so I should send reset pulse periodically to detect it. and as far as I know, there should be no interrupt while ibutton routine is running. but when I read credit card, hundreds of interrupt is occurred in a swipe, and sometimes ibutton routine recognize that there is no ibutton even though ibutton is being attached. so another ibutton attach/detach is recognized. Do you think there is solution for this? frequency of ibutton routine is very low compared with other routines.



Thanks.


Vote
Twitter Facebook LinkedIn
C

You should probably arrange to ignore the ibutton failure if any card reader interrupt occurs during the iButton read. This can be as simple as setting a flag when you start the IButton read, and clearing it on a card interrupt. When the IButton read finishes, if the flag isn't set, ignore the result and try again... or just wait until the next ibutton detection interval.

Clifford Heath.

Vote
Twitter Facebook LinkedIn
J

Thanks. I have deleted my message without noticing your answer. It was not difficult and I should have thought once more before posting this question.

Vote
Twitter Facebook LinkedIn

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required