src-avr: Improve speed of LCD transfers, add hex-code character input

Use a delay loop instead of waiting for clock interrupts to get closer
to maximum LCD update rate.

Add \ escaped hex codes in output testing command.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src-avr/ao_lcd.c b/src-avr/ao_lcd.c
index 6f95b526af9b0e4dffc7aa3f43c09ed6c39ff07f..5bc89bbd91efd74f11b62beb7ce471c7ec850617 100644 (file)
--- a/src-avr/ao_lcd.c
+++ b/src-avr/ao_lcd.c
@@ -108,11 +108,24 @@ ao_lcd_send_nibble(uint8_t rs, uint8_t data)
        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();
+//     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);
 }
@@ -120,8 +133,9 @@ ao_lcd_send_ins(uint8_t data)
 void
 ao_lcd_send_data(uint8_t data)
 {
-       printf ("send data %02x\n", data);
-       ao_lcd_wait_idle();
+//     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);
 }
@@ -198,21 +212,63 @@ ao_lcd_contrast(void)
        }
 }
 
+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)
 {
-       ao_lcd_clear();
+       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') {
-               ao_lcd_send_data(ao_cmd_lex_c);
+               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\0Set LCD contrast" },
-       { ao_lcd_string, "s\0Send string to 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 },
 };