diff options
Diffstat (limited to 'src/drivers/ao_lcd.c')
| -rw-r--r-- | src/drivers/ao_lcd.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/src/drivers/ao_lcd.c b/src/drivers/ao_lcd.c new file mode 100644 index 00000000..5bc89bbd --- /dev/null +++ b/src/drivers/ao_lcd.c @@ -0,0 +1,281 @@ +/* + * Copyright © 2011 Keith Packard <keithp@keithp.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + */ + +#include "ao.h" + +#define LCD_PORT PORTB +#define LCD_DDR DDRB + +#define PIN_RS 4 +#define PIN_E 5 +#define PIN_RW 6 + +void +ao_lcd_set_bits(uint8_t bits) +{ +#if 0 + printf("\tLCD data %x RS %d R/W %d E %d\n", + bits & 0xf, + (bits & (1 << PIN_RS)) ? 1 : 0, + (bits & (1 << PIN_RW)) ? 1 : 0, + (bits & (1 << PIN_E)) ? 1 : 0); +#endif + LCD_PORT = bits; +#if 0 + ao_delay(1); + if (bits & (1 << PIN_RW)) + printf("\tLCD input %x\n", PINB); +#endif +} + +uint8_t +ao_lcd_get_nibble(uint8_t rs) +{ + uint8_t data = (rs ? (1 << PIN_RS) : 0) | (1 << PIN_RW); + uint8_t n; + + DDRB = (1 << PIN_RS) | (1 << PIN_E) | (1 << PIN_RW); + ao_lcd_set_bits(data); + ao_lcd_set_bits(data | (1 << PIN_E)); + n = PINB & 0xf; + ao_lcd_set_bits(data); + return n; +} + +uint8_t +ao_lcd_get_status(void) +{ + uint8_t high, low; + uint8_t data; + + high = ao_lcd_get_nibble(0); + low = ao_lcd_get_nibble(0); + data = (high << 4) | low; + printf ("\tLCD status %02x\n", data); + return data; +} + +uint8_t +ao_lcd_get_data(void) +{ + uint8_t high, low; + uint8_t data; + + high = ao_lcd_get_nibble(1); + low = ao_lcd_get_nibble(1); + data = (high << 4) | low; + printf ("\tLCD data %02x\n", data); + return data; +} + +void +ao_lcd_wait_idle(void) +{ + uint8_t status; + uint8_t count = 0; + + do { + status = ao_lcd_get_status(); + count++; + if (count > 100) { + printf("idle timeout\n"); + break; + } + } while (0); /* status & 0x80); */ +} + +void +ao_lcd_send_nibble(uint8_t rs, uint8_t data) +{ + data = (data & 0xf) | (rs ? (1 << PIN_RS) : 0); + DDRB = (0xf) | (1 << PIN_RS) | (1 << PIN_E) | (1 << PIN_RW); + ao_lcd_set_bits(data); + ao_lcd_set_bits(data | (1 << PIN_E)); + ao_lcd_set_bits(data); +} + +static uint16_t ao_lcd_time = 3; + +void +ao_lcd_delay(void) +{ + volatile uint16_t count; + + for (count = 0; count < ao_lcd_time; count++) + ; +} + +void +ao_lcd_send_ins(uint8_t data) +{ +// printf("send ins %02x\n", data); +// ao_lcd_wait_idle(); +// ao_delay(1); + ao_lcd_delay(); + ao_lcd_send_nibble(0, data >> 4); + ao_lcd_send_nibble(0, data & 0xf); +} + +void +ao_lcd_send_data(uint8_t data) +{ +// printf ("send data %02x\n", data); +// ao_lcd_wait_idle(); + ao_lcd_delay(); + ao_lcd_send_nibble(1, data >> 4); + ao_lcd_send_nibble(1, data & 0x0f); +} + +void +ao_lcd_send_string(char *string) +{ + uint8_t c; + + while ((c = (uint8_t) *string++)) + ao_lcd_send_data(c); +} + +#define AO_LCD_POWER_CONTROL 0x54 + +void +ao_lcd_contrast_set(uint8_t contrast) +{ + ao_lcd_send_ins(AO_LCD_POWER_CONTROL | ((contrast >> 4) & 0x3)); + ao_lcd_send_ins(0x70 | (contrast & 0xf)); +} + +void +ao_lcd_clear(void) +{ + ao_lcd_send_ins(0x01); + ao_delay(1); + /* Entry mode */ + ao_lcd_send_ins(0x04 | 0x02); +} + +void +ao_lcd_start(void) +{ + /* get to 4bit mode */ + ao_lcd_send_nibble(0, 0x3); + ao_lcd_send_nibble(0, 0x3); + ao_lcd_send_nibble(0, 0x3); + ao_lcd_send_nibble(0, 0x2); + + /* function set */ + ao_lcd_send_ins(0x28); + /* function set, instruction table 1 */ + ao_lcd_send_ins(0x29); + + /* freq set */ + ao_lcd_send_ins(0x14); + + /* Power/icon/contrast control*/ + ao_lcd_send_ins(AO_LCD_POWER_CONTROL); + + /* Follower control */ + ao_lcd_send_ins(0x6d); + ao_delay(AO_MS_TO_TICKS(200)); + + /* contrast set */ + ao_lcd_contrast_set(0x18); + + /* Display on */ + ao_lcd_send_ins(0x08 | 0x04); + + /* Clear */ + ao_lcd_clear(); + +} + +void +ao_lcd_contrast(void) +{ + ao_cmd_hex(); + if (ao_cmd_status == ao_cmd_success) { + printf("setting contrast to %02x\n", ao_cmd_lex_i); + ao_lcd_contrast_set(ao_cmd_lex_i & 0x3f); + } +} + +static uint8_t +ao_cmd_hex_nibble(void) +{ + if ('0' <= ao_cmd_lex_c && ao_cmd_lex_c <= '9') + return ao_cmd_lex_c - '0'; + if ('a' <= ao_cmd_lex_c && ao_cmd_lex_c <= 'f') + return ao_cmd_lex_c - ('a' - 10); + if ('A' <= ao_cmd_lex_c && ao_cmd_lex_c <= 'F') + return ao_cmd_lex_c - ('A' - 10); + ao_cmd_status = ao_cmd_syntax_error; + return 0; +} + +void +ao_lcd_string(void) +{ + uint8_t col = 0; + uint8_t c; + + ao_cmd_decimal(); + if (ao_cmd_status != ao_cmd_success) + return; + ao_lcd_send_ins(0x80 | (ao_cmd_lex_i ? 0x40 : 0x00)); + ao_cmd_white(); + while (ao_cmd_lex_c != '\n') { + c = ao_cmd_lex_c; + if (c == '\\') { + ao_cmd_lex(); + c = ao_cmd_hex_nibble() << 4; + ao_cmd_lex(); + c |= ao_cmd_hex_nibble(); + } + ao_lcd_send_data(c); + ao_cmd_lex(); + col++; + } + while (col < 16) { + ao_lcd_send_data(' '); + col++; + } +} + +void +ao_lcd_delay_set(void) +{ + ao_cmd_decimal(); + if (ao_cmd_status == ao_cmd_success) { + printf("setting LCD delay to %d\n", ao_cmd_lex_i); + ao_lcd_time = ao_cmd_lex_i; + } +} + +__code struct ao_cmds ao_lcd_cmds[] = { + { ao_lcd_start, "S\0Start LCD" }, + { ao_lcd_contrast, "C <contrast>\0Set LCD contrast" }, + { ao_lcd_string, "s <line> <string>\0Send string to LCD" }, + { ao_lcd_delay_set, "t <delay>\0Set LCD delay" }, + { 0, NULL }, +}; + +void +ao_lcd_init(void) +{ + DDRB = (1 << PIN_RS) | (1 << PIN_E) | (1 << PIN_RW); + PORTB = 0; + ao_cmd_register(&ao_lcd_cmds[0]); +} |