inputing bits on port D of a PIC18F4680

[Youngpup]

I hope someone can help me. I am trying to read in a 7 bit value through port D. I can only get bits 6,5,4 to read correctly but bits 3,2,1,0 are always low. I can't seem to see anything wrong with the code. The only thing I haven't tried is replacing the PIC(Last resort). Here is the code.

#include "C:\Documents and Settings\tfaulkner.OTTAWA\My Documents\Motor Controller\Software\Motor Controller V1.0.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <can-18xxx8.c>


static int step[8]; // this is an array of steps
static unsigned int8 CAN_BUS_ID; // this is the address for this antenna
static int8 CAN_ALL_ID;// This is for all calibration
static int8 MASTER_ID = 0x00;// this is the ID for the FPGA Card
static int8 buffer[8];// this data storage


Steps(); //
Calibration();
TX_CANBUS();
RX_CANBUS();

void main()
{

RX_CANBUS();


}

RX_CANBUS()
{
struct rx_stat rxstat;
int32 rx_id;

int8 rx_len;
boolean RX;





can_init();
CAN_ALL_ID = 0x7E;
set_tris_d(0xFF);
CAN_BUS_ID = input_d();
rx_id = 0;
step[0] = 0x01;
step[1] = 0x03;
step[2] = 0x02;
step[3] = 0x06;
step[4] = 0x04;
step[5] = 0x0c;
step[6] = 0x08;
step[7] = 0x09;
while(RX = TRUE)
{


if(can_kbhit()) // Message available ?
{
// If so, get the message.
if(can_getd(rx_id, buffer, rx_len, rxstat))
{

if(rx_id == CAN_BUS_ID) // Is it for this board ?
{
Steps();
TX_CANBUS();
}
if(rx_id == CAN_ALL_ID) // Is it for this board ?
{
Calibration();
TX_CANBUS();
}

}
}

}
}

Calibration()
{
int i=0;

while(LIMIT_SW_REAR == 1)
{
output_a(step[7]);//1001
delay_us(1900);
output_a(step[5]);//1100
delay_us(1900);
output_a(step[3]);//0110
delay_us(1900);
output_a(step[1]);//0011
delay_us(1900);
}

while((i<5000) && (LIMIT_SW_FRONT == 1))
{
output_a(step[1]);//1001
delay_us(2000);
output_a(step[3]);//1100
delay_us(2000);
output_a(step[5]);//0110
delay_us(2000);
output_a(step[7]);//0011
delay_us(2000);
i++;
}
}

Steps()
{
int direction;
int num_steps[7];
int i, x;
x=0;
direction = buffer[0];

/* for(i=1; i<8; i++)
{
num_steps[x]=buffer[i];
x++;
}
*/

num_steps[1] = buffer[1];
i=0;

if(direction == 1)
{
while((i<num_steps[1]))// && (LIMIT_SW_FRONT == 1))
{
output_a(step[1]);//1001
delay_us(2000);
output_a(step[3]);//1100
delay_us(2000);
output_a(step[5]);//0110
delay_us(2000);
output_a(step[7]);//0011
delay_us(2000);
i++;
}
}
else
{
while((i<num_steps[1]))// && (LIMIT_SW_REAR == 1))
{
output_a(step[7]);//1001
delay_us(2000);
output_a(step[5]);//1100
delay_us(2000);
output_a(step[3]);//0110
delay_us(2000);
output_a(step[1]);//0011
delay_us(2000);
i++;
}
}
output_a(0b0000);
// for(i=0; i<8; i++)
//{
// buffer[i]=0;
//}


}

TX_CANBUS()
{
int notify;

notify = CAN_BUS_ID;

rotate_left(&notify, 1);

can_putd(MASTER_ID, notify, 1, 1, 1, 0);


}

Thanks.

[dyeatman]

One thought...

Look at page 139 of the data sheet (Port D) and see what else is enabled on those pins that might OVERRIDE the digital inputs.

[Youngpup]

I looked on Page 139. I have commented out PSP part of the 18F4680.h and the Comparator part as well. This still did not help me. Any other suggestions?

[PCM programmer]

1. Post your compiler version.

2. Your code has some other bugs.

[Youngpup]

Thanks for those catches. I had not tested that part of the code yet. I have been stuck on a few other issues like the one at hand. My compiler version is 3.213.

[PCM programmer]

I don't have that version so I can't test it. I think it's likely that the
comparator is turned on. It could be that your version of the compiler
doesn't turn them off. Try adding the following code, which will turn
them off by writing directly to the CMCON register.

[Youngpup]

Thank you, Thank you soooo much. It worked. You are the best.

[frequentguest]

[Ttelmah]

[PCM programmer]

Normally the compiler inserts start-up code which turns off the
comparators. For example, here's the start-up code for the 18F4680
for vs. 4.058: