src-avr: Add LCD driver for NHD-C0216CU-FN-GWB-3V display

[fw/altos] / src-avr / ao_lcd.c

diff --git a/src-avr/ao_lcd.c b/src-avr/ao_lcd.c
new file mode 100644 (file)
index 0000000..6f95b52
--- /dev/null
+++ b/src-avr/ao_lcd.c
@@ -0,0 +1,225 @@
+/*
+ * 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);
+}
+
+void
+ao_lcd_send_ins(uint8_t data)
+{
+       printf("send ins %02x\n", data);
+       ao_lcd_wait_idle();
+       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_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);
+       }
+}
+
+void
+ao_lcd_string(void)
+{
+       ao_lcd_clear();
+       ao_cmd_white();
+       while (ao_cmd_lex_c != '\n') {
+               ao_lcd_send_data(ao_cmd_lex_c);
+               ao_cmd_lex();
+       }
+}
+
+__code struct ao_cmds ao_lcd_cmds[] = {
+       { ao_lcd_start, "S\0Start LCD" },
+       { ao_lcd_contrast, "C\0Set LCD contrast" },
+       { ao_lcd_string, "s\0Send string to LCD" },
+       { 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]);
+}