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azHer
Joined: 01 May 2008
Posts: 7
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| receive data from UART hardware |
 Posted: Thu May 22, 2008 1:29 am |
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Hi All...
I want to send and receive data using PIC and UART hardware.
The data to send is:
unsigned char SelectCard[3]={0xBA,0x02,0x01}
putc(SelectCard[3]);
I will receive data like this:
byte0,byt1,byte2,byt3,byte4,byte5,byt6,byt7,byt8
0xBD,0x08,0x01,0x00,0xAA,0xBB,0xCC,0xDD,0x01
..........................0x01....................................0x02
..........................0x0A....................................0x03
..........................0x0F....................................0x04
byte3 and byte8 has four possible. My problem is I dont know how to use getc(); and at that time check data byte3 must be equal to 0x00 and byte8 must be equal to 0x01, else not accept.
Can any one help me? |
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Ttelmah
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| Posted: Thu May 22, 2008 2:52 am |
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Start with your 'putc'. Putc, accepts _one_ character. Your array has characters at locations SelectCard[0] to SelectCard[2]. The location 'SelectCard[3]', doesn't exist.....
To send the three characters, you need something like:
| Code: |
int8 ctr;
for (ctr=0;ctr<3;ctr++) putc(SelectCard[ctr]);
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The reception is going to need to be basically the same. You will need to read the nine characters, and then 'accept' the value if your conditions are met.
Now, this is _not_ how to do it, if the code needs to be doing much else, but gives a very crude starting point....
| Code: |
int8 ctr;
char rbuff[9];
for (ctr=0;ctr<3;ctr++) putc(SelectCard[ctr]); //send command
for (ctr=0;ctr<9;ctr++) rbuff[ctr]=getc(); //receive 9 response bytes
if (rbuff[3]==0 && rbuff[8]==1) {
//only get here, if the third byte is 0, and the ninth is 1
//execute what you want to do with the data.
}
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Hopefully you get the idea.
Best Wishes |
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azHer
Joined: 01 May 2008
Posts: 7
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| Posted: Thu May 22, 2008 8:34 am |
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| Ttelmah wrote: | Start with your 'putc'. Putc, accepts _one_ character. Your array has characters at locations SelectCard[0] to SelectCard[2]. The location 'SelectCard[3]', doesn't exist.....
To send the three characters, you need something like:
| Code: |
int8 ctr;
for (ctr=0;ctr<3;ctr++) putc(SelectCard[ctr]);
|
The reception is going to need to be basically the same. You will need to read the nine characters, and then 'accept' the value if your conditions are met.
Now, this is _not_ how to do it, if the code needs to be doing much else, but gives a very crude starting point....
| Code: |
int8 ctr;
char rbuff[9];
for (ctr=0;ctr<3;ctr++) putc(SelectCard[ctr]); //send command
for (ctr=0;ctr<9;ctr++) rbuff[ctr]=getc(); //receive 9 response bytes
if (rbuff[3]==0 && rbuff[8]==1) {
//only get here, if the third byte is 0, and the ninth is 1
//execute what you want to do with the data.
}
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Hopefully you get the idea.
Best Wishes |
Thank you for reply me...
I use SelectCard[3] because the communication format from Host to Reader like this:
Header Length Command Checksum
...0xBA ....0x02 .....0x01.....
Header 1 byte, 0xBA mean from Host to Reader
Length 1 byte, calculate from command to checksum
Command 1 byte, 0x01 mean SelectCard
Checksum 1 byte, XOR result from Header to datainclusively
Actually I,m not to understand about this, Can you explain should use SelectCard[3] or just SelectCard[2].
One more thing, If I receive char rbuff[11].
rbuff[7], rbuff[8], rbuff[8], rbuff[10] is equal to value. Can I use like this... rbuff[7]+rbuff[8]+rbuff[8]+rbuff[10]!=0 continue the program... |
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Ttelmah
Guest
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| Posted: Fri May 23, 2008 2:02 am |
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This is really 'basic C'. This forum is meant to be about _CCS_ specific problems and questions. I'm afraid you need to get a simple C tutorial. 'SelectCard[3]', _does not exist_. You want to send three characters, then you have to do as I show, and send all three of them _one at a time_.
Best Wishes |
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azHer
Joined: 01 May 2008
Posts: 7
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| Posted: Wed May 28, 2008 8:01 am |
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Thanks for reply me 
I'm rellly slow in programming. Thanks for your help before.
Here is one more thing I dont know. After send this data:
unsigned char SendData[5]={0XBA,0x03,0x05,0x01,0xB8}
the UART hardware will return this data:
0xDB,0x07,0x05,0x00,0xA1,0x2C,0xEF,0xDC,0x01
how to get byte colour blue(value) after that display it. lcd_putc(); |
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