Part of the problem has been fixed. There were 3 major problems in total:
1: I had forgotten to connect the MCLR pin to a positive supply (with a pull up resistor and capacitor combination of course). So the chip was in constant reset.
2: I had the clock set to RC, instead of HS. I am using a 4 MHz external oscillator.
3: The PIC chip I was using was broken anyway. Hooray for wasting my time.
===
Otherwise the code's still not working properly; nothing's coming out the serial port, HOWEVER, there is a confirmation that the chip is doing what it's supposed to be doing.
From the readings:
It takes around 0.16 ms to sample a pin.
It takes around 1.31 ms to sample 8 pins (1 loop)
It takes 335 ms to loop around 255 times - way too long (The amount of time PORTB 0:3 have high values.)
On the other hand it takes 0.5 ms to get out of the transmission loop. (The amount of time PORTB 4:7 have high values.)
This is the code so far:
===
#include <htc.h>
void main()
{
// AC activate flag
// The PCFG bit will setup all PORTA inputs available to Analogue inputs
// AD result needs to be left justified
// 0000 AN0 - AN7 Analogue inputs
// External Crystal Clock Oscillator works at 4.000 MHz
ADCON0 = 0x81;
ADCON1 = 0x00;
TRISA = 0x2F; // Set AN0 - AN4 on PORTA to be inputs
TRISB = 0x00;
TRISC = 0xC0; // Setting up USART for transmission from Tx PIN Asynchronous Mode
TRISD = 0x00;
TRISE = 0x17; // PSPMODE bit set to turn PORTE into I/O ports - AN5 - AN7 on PORTE to be inputs
PORTA = 0x00;
PORTB = 0x00;
PORTC = 0x00;
PORTD = 0x00;
PORTE = 0x00;
INTCON = 0x00; // Interrupt Registers
// PIR1 = 0x00; // Don't touch this register - Bit 4 is the TXREG clear bit
RCSTA = 0x80; // Serial Port ENABLE bit
// PIE1 = 0x00; // Bit 5 TXIE controls the interrupt function for TXREG
TXSTA = 0x36; // Setting up USART for Tx
SPBRG = 0x00; // Baud Rate Generator
unsigned char timerStart;
unsigned int timerCount;
unsigned int timerEnd;
unsigned char i; // general index counter
unsigned char pLabel; // general storage
unsigned char pData[8]; // storage for A/D values from analogue inputs
unsigned char pTimer[8]; // storage for timer values
unsigned char acquire0; // Acquisition Time Delay counter
// adc_on = 1;
// Activate AD module
timerStart = 0;
timerCount = 0;
timerEnd = 255; // Ending value for when information is sent to USART
while (1)
{
{
PORTB = 0x0F; // Output TEST
// Channel 0 AN0 PIN 2
ADCON0 = 0x81;
acquire0=4;
for (i=1;i<acquire0;i++) //acquisiton time delay
{
asm("clrwdt");
}
ADGO=1; // Start conversion
while(ADGO==1)
{
asm("clrwdt");
}
if (ADRESH > pData[0])
{
timerStart = 1;
pData[0] = ADRESH; // Send value to pData[0];
pTimer[0] = timerCount; // Send timer value to pTimer[0];
}
}
{
asm ("clrwdt");
}
{
// Channel 1 AN1 PIN 3
ADCON0 = 0x89;
acquire0=4;
for (i=1;i<acquire0;i++) //acquisiton time delay
{
asm("clrwdt");
}
ADGO=1; // Start conversion
while(ADGO==1)
{
asm("clrwdt");
}
if (ADRESH > pData[1])
{
timerStart = 1;
pData[1] = ADRESH; // Send value to pData[1];
pTimer[1] = timerCount; // Send timer value to pTimer[1];
}
}
{
asm ("clrwdt");
}
{
// Channel 2 AN2 PIN 4
ADCON0 = 0x91;
acquire0=4;
for (i=1;i<acquire0;i++) //acquisiton time delay
{
asm("clrwdt");
}
ADGO=1; // Start conversion
while(ADGO==1)
{
asm("clrwdt");
}
if (ADRESH > pData[2])
{
timerStart = 1;
pData[2] = ADRESH; // Send value to pData[2]
pTimer[2] = timerCount; // Send timer value to pTimer[2];
}
}
{
asm ("clrwdt");
}
{
// Channel 3 AN3 PIN 5
ADCON0 = 0x99;
acquire0=4;
for (i=1;i<acquire0;i++) //acquisiton time delay
{
asm("clrwdt");
}
ADGO=1; // Start conversion
while(ADGO==1)
{
asm("clrwdt");
}
if (ADRESH > pData[3])
{
timerStart = 1;
pData[3] = ADRESH; // Send value to pData[3]
pTimer[3] = timerCount; // Send timer value to pTimer[3];
}
}
{
asm ("clrwdt");
}
{
// Channel 4 AN4 PIN 7
ADCON0 = 0xA1;
acquire0=4;
for (i=1;i<acquire0;i++) //acquisiton time delay
{
asm("clrwdt");
}
ADGO=1; // Start conversion
while(ADGO==1)
{
asm("clrwdt");
}
if (ADRESH > pData[4])
{
timerStart = 1;
pData[4] = ADRESH; // Send value to pData[4]
pTimer[4] = timerCount; // Send timer value to pTimer[4];
}
}
{
asm ("clrwdt");
}
{
// Channel 5 AN5 PIN 8
ADCON0 = 0xA9;
acquire0=4;
for (i=1;i<acquire0;i++) //acquisiton time delay
{
asm("clrwdt");
}
ADGO=1; // Start conversion
while(ADGO==1)
{
asm("clrwdt");
}
if (ADRESH > pData[5])
{
timerStart = 1;
pData[5] = ADRESH; // Send value to pData[5]
pTimer[5] = timerCount; // Send timer value to pTimer[5];
}
}
{
asm ("clrwdt");
}
{
// Channel 6 AN6 PIN 9
ADCON0 = 0xB1;
acquire0=4;
for (i=1;i<acquire0;i++) //acquisiton time delay
{
asm("clrwdt");
}
ADGO=1; // Start conversion
while(ADGO==1)
{
asm("clrwdt");
}
if (ADRESH > pData[6])
{
timerStart = 1;
pData[6] = ADRESH; // Send value to pData[6]
pTimer[6] = timerCount; // Send timer value to pTimer[6];
}
}
{
asm ("clrwdt");
}
{
// Channel 7 AN7 PIN 10
ADCON0 = 0xB9;
acquire0=4;
for (i=1;i<acquire0;i++) //acquisiton time delay
{
asm("clrwdt");
}
ADGO=1; // Start conversion
while(ADGO==1)
{
asm("clrwdt");
}
if (ADRESH > pData[7])
{
timerStart = 1;
pData[7] = ADRESH; // Send value to pData[7]
pTimer[7] = timerCount; // Send timer value to pTimer[7];
}
}
{
asm ("clrwdt");
}
/* This should be the code to send stored in the general purpose registers to the Tx*/
if (timerCount >= timerEnd)
{
PORTB = 0xF0; // Data Output TEST
TXREG = 0X55; // Send Data Send Byte
pLabel = 0xA0;
for (i = 0; i<8; i++)
{
TXREG = pLabel; // Send data i Byte 1 - Label A0
TXREG = pTimer
; // Send data i Byte 2 - Timer Value
TXREG = pData; // Send data i Byte 3 - A/D result
pLabel++;
}
for(i = 0; i<8; i++) // clear A/D data and timer arrays
{
pData = 0;
pTimer = 0;
}
timerCount = 0; // Reset Timer
timerStart = 0; // Cycle complete - Turn timer off
{
asm ("clrwdt");
}
}
if (timerStart == 1)
{
timerCount++;
}
{
asm ("clrwdt");
}
} // End while(1)
} // End main
===
What I need to find out is why the TXREG isn't sending anything whatsoever.