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| 5V uart hardware |
 Posted: Thu May 28, 2009 7:53 pm |
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I just buy this hardware and I don't know how to connect. This hardware working at 5V, UART and TTL level. Only four pin, there is Rx, Tx, Ground and 5V.
I try to connect using MAX232 but it is not working. My PIC is working well with hyperterminal. Should I connect this hardware direct to PIC? or other way? and how to command in rs232...
Thanks for any expertise  |
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asmallri
Joined: 12 Aug 2004
Posts: 1635
Location: Perth, Australia
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| Re: 5V uart hardware |
| Posted: Thu May 28, 2009 11:24 pm |
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| Anonymous wrote: | | I just buy this hardware and I don't know how to connect. This hardware working at 5V, UART and TTL level. Only four pin, there is Rx, Tx, Ground and 5V. |
What hardware? Post a link to the hardware.
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Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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SherpaDoug
Joined: 07 Sep 2003
Posts: 1640
Location: Cape Cod Mass USA
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| Posted: Sun May 31, 2009 11:14 am |
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Can you tell us the signal voltage when the line is idle, and the voltage when the a data bit is active? Also giving us a link to the hardware datasheet would be ideal.
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The search for better is endless. Instead simply find very good and get the job done. |
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azHer
Joined: 01 May 2008
Posts: 7
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| Posted: Mon Jun 01, 2009 11:22 pm |
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This is the hardware link.
http://www.stronglink.cn/english/sl015m1.htm
When I powered 5V to this hardware all pin Rx and Tx are 5V.
I try this code but it's no work. It just stop after display Hex number
| Code: | #include <16F877A.h>
#fuses HS,NOWDT,PUT,NOPROTECT,BROWNOUT,NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, STREAM=PC, ERRORS)
#use rs232(baud=9600, xmit=PIN_B1, rcv=PIN_B2, STREAM=RFID, ERRORS)
#include <flex_lcd.c>
#define cardSta PIN_B5
char GetID[4] = {0xBA,0x02,0x01,0xB9};
int8 ctr;
char rbuff[10];
//============================
void main()
{
char c;
lcd_init();
fprintf(PC,"Touch Your Card\n\r");
while(1){
if(input(cardSta)==0){
fprintf(PC,"card detected\n\r");
for (ctr=0;ctr<4;ctr++){
printf(lcd_putc,"%X",GetID[ctr]);
delay_ms(1000);
}
for (ctr=0;ctr<4;ctr++){
fprintf(PC,"%X",GetID[ctr]);
delay_ms(1000);
}
[b]// start here it's no work[/b]
for (ctr=0;ctr<4;ctr++) {
fputc(GetID[ctr],RFID); //send command to get ID
}
for (ctr=0;ctr<10;ctr++) {
rbuff[ctr]=fgetc(RFID); //receive 10 response byte
}
for (ctr=0;ctr<10;ctr++) {
fprintf(PC,"%X", rbuff[ctr]);
}
}
else{
fprintf(PC,"card not detect\n\r");
delay_ms(3000);
}
}
} |
Other example is here, using other uC:
http://narong.ee.engr.tu.ac.th/microlab/doc/rfid/
Plz help (I have no basic on C and PIC) just learn from this forum. |
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FvM
Joined: 27 Aug 2008
Posts: 2337
Location: Germany
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| Posted: Tue Jun 02, 2009 2:37 am |
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| TTL level UART clearly has to be connected to PIC UART pins directly. And of course, the signals have to be cross wired input to output. A MAX232 can possibly damage a connected TTL level hardware. However, with a correct connection and functional hardware, there may be other problems as well, e.g. an incorrect baud rate selected. |
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azHer
Joined: 01 May 2008
Posts: 7
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| Posted: Tue Jun 02, 2009 8:41 pm |
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I already ask the supplier about baud rate setting. The baud is 115,200.
I try at this baud rate with the above code, but no work. Anyone has an idea? How should I try this in other way |
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FvM
Joined: 27 Aug 2008
Posts: 2337
Location: Germany
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| Posted: Tue Jun 02, 2009 11:32 pm |
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| If it's really 115k, it surely doesn't work with a software UART, as used in your code. But as far as I understood, the Mifare module has soldered jumpers to set the baud rate. You can either change it to 9k6 or must use the PIC hardware UART to access the module. |
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