circuitpython/stm/lcd.c

210 lines
6.7 KiB
C

#include <string.h>
#include <stm32f4xx_gpio.h>
#include "misc.h"
#include "systick.h"
#include "lcd.h"
#include "font_petme128_8x8.h"
#define PYB_LCD_PORT (GPIOA)
#define PYB_LCD_CS1_PIN (GPIO_Pin_0)
#define PYB_LCD_RST_PIN (GPIO_Pin_1)
#define PYB_LCD_A0_PIN (GPIO_Pin_2)
#define PYB_LCD_SCL_PIN (GPIO_Pin_3)
#define PYB_LCD_SI_PIN (GPIO_Pin_4)
#define LCD_INSTR (0)
#define LCD_DATA (1)
static void lcd_out(int instr_data, uint8_t i) {
sys_tick_delay_ms(0);
PYB_LCD_PORT->BSRRH = PYB_LCD_CS1_PIN; // CS=0; enable
if (instr_data == LCD_INSTR) {
PYB_LCD_PORT->BSRRH = PYB_LCD_A0_PIN; // A0=0; select instr reg
} else {
PYB_LCD_PORT->BSRRL = PYB_LCD_A0_PIN; // A0=1; select data reg
}
// send byte bigendian, latches on rising clock
for (uint32_t n = 0; n < 8; n++) {
sys_tick_delay_ms(0);
PYB_LCD_PORT->BSRRH = PYB_LCD_SCL_PIN; // SCL=0
if ((i & 0x80) == 0) {
PYB_LCD_PORT->BSRRH = PYB_LCD_SI_PIN; // SI=0
} else {
PYB_LCD_PORT->BSRRL = PYB_LCD_SI_PIN; // SI=1
}
i <<= 1;
sys_tick_delay_ms(0);
PYB_LCD_PORT->BSRRL = PYB_LCD_SCL_PIN; // SCL=1
}
PYB_LCD_PORT->BSRRL = PYB_LCD_CS1_PIN; // CS=1; disable
/*
in Python, native types:
CS1_PIN(const) = 0
n = int(0)
delay_ms(0)
PORT[word:BSRRH] = 1 << CS1_PIN
for n in range(0, 8):
delay_ms(0)
PORT[word:BSRRH] = 1 << SCL_PIN
if i & 0x80 == 0:
PORT[word:BSRRH] = 1 << SI_PIN
else:
PORT[word:BSRRL] = 1 << SI_PIN
i <<= 1
delay_ms(0)
PORT[word:BSRRL] = 1 << SCL_PIN
*/
}
/*
static void lcd_data_out(uint8_t i) {
delay_ms(0);
PYB_LCD_PORT->BSRRH = PYB_LCD_CS1_PIN; // CS=0; enable
PYB_LCD_PORT->BSRRL = PYB_LCD_A0_PIN; // A0=1; select data reg
// send byte bigendian, latches on rising clock
for (uint32_t n = 0; n < 8; n++) {
delay_ms(0);
PYB_LCD_PORT->BSRRH = PYB_LCD_SCL_PIN; // SCL=0
if ((i & 0x80) == 0) {
PYB_LCD_PORT->BSRRH = PYB_LCD_SI_PIN; // SI=0
} else {
PYB_LCD_PORT->BSRRL = PYB_LCD_SI_PIN; // SI=1
}
i <<= 1;
delay_ms(0);
PYB_LCD_PORT->BSRRL = PYB_LCD_SCL_PIN; // SCL=1
}
PYB_LCD_PORT->BSRRL = PYB_LCD_CS1_PIN; // CS=1; disable
}
*/
#define LCD_BUF_W (16)
#define LCD_BUF_H (4)
char lcd_buffer[LCD_BUF_W * LCD_BUF_H];
int lcd_line;
int lcd_column;
int lcd_next_line;
void lcd_init(void) {
// set the outputs high
PYB_LCD_PORT->BSRRL = PYB_LCD_CS1_PIN;
PYB_LCD_PORT->BSRRL = PYB_LCD_RST_PIN;
PYB_LCD_PORT->BSRRL = PYB_LCD_A0_PIN;
PYB_LCD_PORT->BSRRL = PYB_LCD_SCL_PIN;
PYB_LCD_PORT->BSRRL = PYB_LCD_SI_PIN;
// make them push/pull outputs
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = PYB_LCD_CS1_PIN | PYB_LCD_RST_PIN | PYB_LCD_A0_PIN | PYB_LCD_SCL_PIN | PYB_LCD_SI_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(PYB_LCD_PORT, &GPIO_InitStructure);
// init the LCD
sys_tick_delay_ms(1); // wait a bit
PYB_LCD_PORT->BSRRH = PYB_LCD_RST_PIN; // RST=0; reset
sys_tick_delay_ms(1); // wait for reset; 2us min
PYB_LCD_PORT->BSRRL = PYB_LCD_RST_PIN; // RST=1; enable
sys_tick_delay_ms(1); // wait for reset; 2us min
lcd_out(LCD_INSTR, 0xa0); // ADC select, normal
lcd_out(LCD_INSTR, 0xc8); // common output mode select, reverse
lcd_out(LCD_INSTR, 0xa2); // LCD bias set, 1/9 bias
lcd_out(LCD_INSTR, 0x2f); // power control set, 0b111=(booster on, vreg on, vfollow on)
lcd_out(LCD_INSTR, 0x21); // v0 voltage regulator internal resistor ratio set, 0b001=small
lcd_out(LCD_INSTR, 0x81); // electronic volume mode set
lcd_out(LCD_INSTR, 0x34); // electronic volume register set, 0b110100
lcd_out(LCD_INSTR, 0x40); // display start line set, 0
lcd_out(LCD_INSTR, 0xaf); // LCD display, on
// clear display
for (int page = 0; page < 4; page++) {
lcd_out(LCD_INSTR, 0xb0 | page); // page address set
lcd_out(LCD_INSTR, 0x10); // column address set upper
lcd_out(LCD_INSTR, 0x00); // column address set lower
for (int i = 0; i < 128; i++) {
lcd_out(LCD_DATA, 0x00);
}
}
for (int i = 0; i < LCD_BUF_H * LCD_BUF_W; i++) {
lcd_buffer[i] = ' ';
}
lcd_line = 0;
lcd_column = 0;
lcd_next_line = 0;
}
void lcd_print_str(const char *str) {
lcd_print_strn(str, strlen(str));
}
void lcd_print_strn(const char *str, unsigned int len) {
int redraw_min = lcd_line * LCD_BUF_W + lcd_column;
int redraw_max = redraw_min;
int did_new_line = 0;
for (; len > 0; len--, str++) {
// move to next line if needed
if (lcd_next_line) {
if (lcd_line + 1 < LCD_BUF_H) {
lcd_line += 1;
} else {
lcd_line = LCD_BUF_H - 1;
for (int i = 0; i < LCD_BUF_W * (LCD_BUF_H - 1); i++) {
lcd_buffer[i] = lcd_buffer[i + LCD_BUF_W];
}
for (int i = 0; i < LCD_BUF_W; i++) {
lcd_buffer[LCD_BUF_W * (LCD_BUF_H - 1) + i] = ' ';
}
redraw_min = 0;
redraw_max = LCD_BUF_W * LCD_BUF_H;
}
lcd_next_line = 0;
lcd_column = 0;
did_new_line = 1;
}
if (*str == '\n') {
lcd_next_line = 1;
} else if (lcd_column >= LCD_BUF_W) {
lcd_next_line = 1;
str -= 1;
len += 1;
} else {
lcd_buffer[lcd_line * LCD_BUF_W + lcd_column] = *str;
lcd_column += 1;
int max = lcd_line * LCD_BUF_W + lcd_column;
if (max > redraw_max) {
redraw_max = max;
}
}
}
int last_page = -1;
for (int i = redraw_min; i < redraw_max; i++) {
int page = i / LCD_BUF_W;
if (page != last_page) {
int offset = 8 * (i - (page * LCD_BUF_W));
lcd_out(LCD_INSTR, 0xb0 | page); // page address set
lcd_out(LCD_INSTR, 0x10 | ((offset >> 4) & 0x0f)); // column address set upper
lcd_out(LCD_INSTR, 0x00 | (offset & 0x0f)); // column address set lower
last_page = page;
}
int chr = lcd_buffer[i];
if (chr < 32 || chr > 126) {
chr = 127;
}
const uint8_t *chr_data = &font_petme128_8x8[(chr - 32) * 8];
for (int i = 0; i < 8; i++) {
lcd_out(LCD_DATA, chr_data[i]);
}
}
if (did_new_line) {
sys_tick_delay_ms(200);
}
}