So this is probably a long shot, but I figured i'd give it a shot.
Basically im trying to manually get 1 character even printing on a generic 20x4 LCD screen (purchased this specifically: https://www.adafruit.com/product/198)
So my code is SUPER basic, because im basically trying to replicate their "example" on page 42 with 4 bit mode: https://cdn-shop.adafruit.com/datasheets/HD44780.pdf
here is my code:
#include "tm4c123gh6pm.h"
#define PORTB (*((volatile unsigned long *)0x400050FC))
#define GPIO_PORTB_OUT (*((volatile unsigned long *)0x400050FC)) // bits 5-0
#define GPIO_PORTB_DIR_R (*((volatile unsigned long *)0x40005400))
#define GPIO_PORTB_AFSEL_R (*((volatile unsigned long *)0x40005420))
#define GPIO_PORTB_DEN_R (*((volatile unsigned long *)0x4000551C))
#define GPIO_PORTB_AMSEL_R (*((volatile unsigned long *)0x40005528))
#define GPIO_PORTB_PCTL_R (*((volatile unsigned long *)0x4000552C))
#define GPIO_PORTE_IN (*((volatile unsigned long *)0x4002400C)) // bits 1-0
#define SENSOR (*((volatile unsigned long *)0x4002400C))
#define GPIO_PORTE_DIR_R (*((volatile unsigned long *)0x40024400))
#define GPIO_PORTE_AFSEL_R (*((volatile unsigned long *)0x40024420))
#define GPIO_PORTE_DEN_R (*((volatile unsigned long *)0x4002451C))
#define GPIO_PORTE_AMSEL_R (*((volatile unsigned long *)0x40024528))
#define GPIO_PORTE_PCTL_R (*((volatile unsigned long *)0x4002452C))
#define SYSCTL_RCGC2_R (*((volatile unsigned long *)0x400FE108))
#define SYSCTL_RCGC2_GPIOE 0x00000010 // port E Clock Gating Control
#define SYSCTL_RCGC2_GPIOB 0x00000002 // port B Clock Gating Control
// This assumes that the hookups PB3-PB0 = D7-D4
// RS = PB4
// EN = PB5
// Inputs: Number of msec to delayMS
// Outputs: None
void delayMS(unsigned long msec){
unsigned long count;
while(msec > 0 ) { // repeat while there are still delayMS
count = 16000; // about 1ms
while (count > 0) {
count--;
} // This while loop takes approximately 3 cycles
msec--;
}
}
int main(void){
volatile unsigned long delay;
SYSCTL_RCGC2_R |= 0x12; // 1) B E
delay = SYSCTL_RCGC2_R; // 2) no need to unlock
GPIO_PORTB_AMSEL_R &= ~0x3F; // 3) disable analog function on PB5-0
GPIO_PORTB_PCTL_R &= ~0x00FFFFFF; // 4) enable regular GPIO
GPIO_PORTB_DIR_R |= 0x3F; // 5) outputs on PB5-0
GPIO_PORTB_AFSEL_R &= ~0x3F; // 6) regular function on PB5-0
GPIO_PORTB_DEN_R |= 0x3F; // 7) enable digital on PB5-0
while(1){
PORTB = 0x02;
delayMS(5);
PORTB = 0x12; //enable on
delayMS(5);
PORTB = 0x02; //enable off
PORTB = 0x02;
delayMS(5);
PORTB = 0x12; //enable on
delayMS(5);
PORTB = 0x02; //enable off
PORTB = 0x10; //enable on
delayMS(5);
PORTB = 0x00; //enable off
PORTB = 0x10; //enable on
delayMS(5);
PORTB = 0x00; //enable off
PORTB = 0x10; //enable on
delayMS(5);
PORTB = 0x2E;
delayMS(5);
PORTB = 0x00; //enable off
PORTB = 0x10; //enable on
delayMS(5);
PORTB = 0x26;
delayMS(5);
PORTB = 0x00; //enable off
PORTB = 0x10; //enable on
delayMS(5);
PORTB = 0x34;
delayMS(5);
PORTB = 0x00; //enable off
PORTB = 0x10; //enable on
delayMS(5);
PORTB = 0x38;
delayMS(5);
PORTB = 0x00; //enable off
PORTB = 0x00;
delayMS(5);
PORTB |= 0x00;
delayMS(5);
PORTB |= 0x00;
}
}
It's pretty basic, because im pretty new to using the TIVA board. I can do basic GPIO stuff but nothing fancy. I also realize HAL libraries exist..but I was just trying to follow this "example" code in the debugger sending the exact commands. I don't have R/Whooked up , it's tied to ground. Enable is PB5, and RS is PB4 with DB7-DB4 being PB3-0
I am certain it is hooked up on the breadboard fine. But im sure im just missing something obvious. I read over the datasheet, and from my understanding, I need to bring enable high--->do command---->turn enable off? So im trying to use small delays.
Any ideas? This may not be the proper forum but I figured i'd give it a shot.
