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HAI, I would like to implement TTL interface to a swipe card reader. I want to read track 2 of a card .This contains alphanumeric characters and each character is of 5 bit size which includes one parity bit. I designed a hardware circuit for this with AT89c2051. The data is coming as a stream of bits from the readers magnetic head. So I have store this bit stream to a bit array. I used bdata variable for this purpose, but is not possible to write to the bit position. How I can write these bits to my bit array? What is wrong with code below: I used the pin P1.6 as the input for the data from card reader's magnetic head. Please help me.
sbit dat=P1^6; bdata unsigned char mydata[13]; for (i = 0; i < 13; i++) { for (mask = 0x01; mask != 0x00; mask <<= 1) { mydata[i] & mask = dat; } }
Here the error I got is errorC141:syntax error near'=';
Please give a replay.
If your code works in simulator & not in actual circuit, most probably your circut has different timings. Ive' have ot got the code and cannot see the problem(havn't run it), here are my suggesitions, 1) Make sure you wait atleast 30mSec before it's initialization is started. To be on the safer side use more delays than what they specifies.
Hope that helps. If you still having problems I'll post a example with C which you can easily convert to ASM.
Hai Friend, My code get some compilation error as mentioned in my first post. So the problem I think is not in hardware, but in code itself. If I get a single bit from a card, then it is possible to store in a single bit. But if it is a stream of bits, then I have to store in a bit array. How can I define a bit array and how its bits can be accessed. Actually there is 8 bits in a char, but I am not able store a bit in its bit0 or bit1 etc. Is it possible using Keil to store a stream of bits to such a variable. Is it possible to use bdata variable for this purpose? Please help me with a sample code.