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Serially reading into PIC
- Thread starter QMD
- Start date
RFID reader are really not that hard to use there serial devices. Most use a baud rate of 2400 or 9600.
Set the pic to receive at the right baud and enable the card reader is about all there is to it.
You can test the card with a max232 to find the cards number.
Here a look at it working http://www.youtube.com/watch?v=I4-TXLs4lbk
Set the pic to receive at the right baud and enable the card reader is about all there is to it.
You can test the card with a max232 to find the cards number.
Here a look at it working http://www.youtube.com/watch?v=I4-TXLs4lbk
Another issue we are currently facing is that our RFID reader is not reading as far as we desired...we are trying to read ~1m...but we are only getting 1 foot, at max. Any suggestions on places where one can get a UHF antenna? We need to change the antenna to one with a higher gain, in efforts to get more range
This should give you a good idea of how to do this The code is by ericgibbs
You'll have to change to match your carder baud rate
You'll have to change to match your carder baud rate
Rich (BB code):
list p=16f877A ; list directive to define processor
#include <p16f877A.inc> ; processor specific variable definitions
errorlevel -302, -207
__CONFIG _CP_OFF & _WDT_OFF & _BODEN_OFF & _PWRTE_ON & _RC_OSC & _WRT_OFF & _LVP_ON & _CPD_OFF
bank0 macro
bcf 03h,5
bcf 03h,6 ; ram page 0
endm
bank1 macro
bsf 03h,5
bcf 03h,6 ; ram page 1
endm
;---------------------------------------------------------------------------
;bit spen (rcsta<7>) and bits trisc<7:6> have tobe set
bank0
bsf 18h,7
bsf 07h,6
bank1
movlw 00h
movwf 88h
bsf 87h,7
;---------------------------------------------------------------------------
;1. initialize the spbrg register for the appropriate
;baud rate. if a high speed baud rate is desired,
;set bit brgh (section 10.1).
bank1
bsf 98h,2
movlw 0ch ;baud rate = 19,2 k
movwf 99h ;4 mhz
;---------------------------------------------------------------------------
;2. enable the asynchronous serial port by clearing
;bit sync and setting bit spen.
bank1
bcf 98h,4
bank0
bsf 18h,7
;---------------------------------------------------------------------------
;3. If interrupts are desired, then set enable bit
;RCIE..
bank1
bcf 8ch,5
;---------------------------------------------------------------------------
;4. 4. If 9-bit reception is desired, then set bit RX9.
bank0
bcf 18h,6
;---------------------------------------------------------------------------
; 5. Enable the reception by setting bit CREN.
bank0
bsf 18h,4
;---------------------------------------------------------------------------
;6. Flag bit RCIF will be set when reception is complete
;and an interrupt will be generated if enable
;bit RCIE is set.
;---------------------------------------------------------------------------
;7. Read the RCSTA register to get the ninth bit (if
;enabled) and determine if any error occurred
;during reception.
;---------------------------------------------------------------------------
;8. Read the 8-bit received data by reading the
;RCREG register.
vrti
bank0
movf RCREG,0 ;byte that I send to LED on PORTD
movwf PORTD ;txreg
;bank1
cekaj btfss PIR1,5
goto cekaj
goto vrti
;---------------------------------------------------------------------------
;8. if using interrupts, ensure that gie and peie
;(bits 7 and 6) of the intcon register are set.
endThanks..is there a C version available somewhere?
Oh my bad...I am using PIC-C
I am under the assumption that I will still need a max232 IC for proper rs232 communication
For output, I've been told that it is via a printf function, outputting via the specified pin
Would I use a scanf to read data?
You need the max from the pic to the PC I only have the demo of PIC-C and it ran out years ago I would use MikroC it doesn't have a time limit and is way easier to use.
Rich (BB code):
UART1_Init(9600); // Initialize UART module at 9600 bps
Delay_ms(100); // Wait for UART module to stabilize
UART1_Write_Text("Start");
while (1) { // Endless loop
if (UART1_Data_Ready()) { // If data is received,
uart_rd = UART1_Read(); // read the received data,
UART1_Write(uart_rd); // and send data via UART
}
}
}Okay...so I have moved over to the dsPIC30f4011, as I need to do some serial I/O from two ports
Here is some sample code I found online....but I get many errors...
I also tried my own test code, with no avail:
Both gave me an error regarding "heap" and that "#use" was an invalid preprocessing directive
Here is some sample code I found online....but I get many errors...
Rich (BB code):
/////////////////////////////////////////////////////////////////////////
//// EX_SQW.C ////
//// ////
//// This program displays a message over the RS-232 and waits for ////
//// any keypress to continue. The program will then begin a 1khz ////
//// square wave over I/O pin B4. ////
//// ////
//// Comment out the printf's and getc to eliminate the RS232 and ////
//// just output a square wave. ////
//// ////
//// Change both delay_us to delay_ms to make the frequency 1 hz. ////
//// This will be more visable on a LED. ////
//// ////
//// ////
//// Change the device, clock and RS232 pins for your hardware if ////
//// needed. ////
/////////////////////////////////////////////////////////////////////////
#include <p30F4011.h>
#include <stdio.h>
//#device ICD=TRUE // For using the debugger, un-comment
#use delay(crystal=20mhz)
// UART1A specifies the alternate UART pins Pin_C13, Pin_C14
// use UART1 to sprcify UART for pins Pin_F3, Pin_F2
#use rs232(baud=9600, UART1A)
int main() {
printf("Press any key to beginnr");
getc();
printf("1 khz signal activatednr");
while (1) {
output_high(PIN_B4);
delay_us(500);
output_low(PIN_B4);
delay_us(500);
}
return 0;
}
Rich (BB code):
#include "p30f4011.h"
#include <stdio.h>
#use rs232(baud=9600, xmit=U1TX, rcv=U1RZ) //serial port output pin & baud rate
// Set up the serial connection to use 9600 buad rate
void setupUSART1()
{
U1BRG = 11; //set baud rate to ~9600bps at 7.37MHz (FRC oscillator)
U1MODEbits.STSEL = 0; //1 stop bit
U1MODEbits.PDSEL = 0; //8-bit, no parity
U1MODEbits.UARTEN = 1; //enable UART1
U1STAbits.UTXEN = 1; //enable UART1 transmitter
U1STAbits.URXISEL = 3; //Enable 4 character
}
int main(void)
{
setupUSART1();
printf("Hello");
return 0;
}ok i figured out the issue regarding heap
this program compiles, but no output..
this program compiles, but no output..
Rich (BB code):
#include "p30f4011.h"
#include <stdio.h>
void setupUSART1()
{
U1BRG = 11; //set baud rate to ~9600bps at 7.37MHz (FRC oscillator)
U1MODEbits.STSEL = 0; //1 stop bit
U1MODEbits.PDSEL = 0; //8-bit, no parity
U1MODEbits.UARTEN = 1; //enable UART1
U1STAbits.UTXEN = 1; //enable UART1 transmitter
U1STAbits.URXISEL = 3; //Enable 4 character
}
int main()
{
//Initialization
// setupADC();
// setupPWMs();
setupUSART1();
printf("Starting up...\n\r");
// delay();
TRISBbits.TRISB2 = 0; //set Port B pin 2 to output
//main loop
while (1)
{ printf("Hello");
}
return 0;
}
