o Party functional LCD code.

1 files changed, 129 insertions, 68 deletions

diff --git a/LiquidCrystal.c b/LiquidCrystal.c
index becc07e..eed30c8 100644
--- a/LiquidCrystal.c
+++ b/LiquidCrystal.c
@@ -1,13 +1,14 @@
 #include "LiquidCrystal.h"
+#include "nrf_delay.h"
+#include "nrf_error.h"
 #include "nrf_gpio.h"
-#include "app_timer.h"
 
 /*
  * Arduino | LCD | nrf51
  *      D4 | DB4 | P0.16
  *      D5 | DB5 | P0.17
  *      D6 | DB6 | P0.18
- *      D7 | DB7 | P0.10
+ *      D7 | DB7 | P0.19
  *      D8 |  RS | P0.20, register select. 0=instruction (write), 0=busy (read), 1=data
  *      D9 |  EN | P0.23, clock, data is clocked in/out on falling edge
  *     D10 | DB4 | P0.24
@@ -31,103 +32,109 @@ static struct {
     uint8_t pin_db7;
     uint8_t pin_rs;
     uint8_t pin_en;
-
-    app_gpiote_user_id_t gpio_user_id;
 } data = { .pin_db4 = 16, .pin_db5 = 17, .pin_db6 = 18, .pin_db7 = 19, .pin_rs =
         20, .pin_en = 23, };
 
-static uint32_t ticks_per_ms;
-
-static void event_handler() {
-}
-
-static void wait_ms(uint32_t ms) {
-    uint32_t ticks;
-
-    app_timer_cnt_get(&ticks);
-
-    const uint32_t end_ticks = ticks + ms * ticks_per_ms;
-
-    do {
-        app_timer_cnt_get(&ticks);
-    } while (ticks < end_ticks);
-}
-
 static void write_4(uint8_t value) {
     nrf_gpio_pin_write(data.pin_db4, value & 0x01);
     nrf_gpio_pin_write(data.pin_db5, value & 0x02);
     nrf_gpio_pin_write(data.pin_db6, value & 0x04);
     nrf_gpio_pin_write(data.pin_db7, value & 0x08);
 
+    nrf_delay_us(10);
     nrf_gpio_pin_set(data.pin_en);
+    nrf_delay_us(10); // 450ns is supposed to be sufficient
     nrf_gpio_pin_clear(data.pin_en);
 }
 
-static void write_value(uint8_t value, bool is_data) {
+static void write_value(uint8_t value, bool is_data, uint32_t delay) {
     nrf_gpio_pin_write(data.pin_rs, is_data);
 
     write_4(value >> 4);
     write_4(value);
-}
-
-static void begin() {
-    nrf_gpio_pin_clear(data.pin_rs);
-    nrf_gpio_pin_clear(data.pin_en);
 
-    // SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
-    // according to datasheet, we need at least 40ms after power rises above 2.7V
-    // before sending commands. Arduino can turn on way before 4.5V so we'll wait 50
-    wait_ms(50);
-
-    write_4(0x03);
-    wait_ms(5); // 4.5ms
-
-    write_4(0x03);
-    wait_ms(5); // 4.5ms
-
-    write_4(0x03);
-    wait_ms(5); // 4.5ms
-
-    write_4(0x02);
-
-    write_value(LIQUID_CRYSTAL_CMD_DISPLAY, false);
-
-//	_displaycontrol = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF;
-    liquid_crystal_display(true, true, true);
+    nrf_delay_us(delay);
 }
 
 void liquid_crystal_write_char(char chr) {
-    write_value(chr, true);
+    write_value(chr, true, 50);
 }
 
 void liquid_crystal_write_string(char *chr) {
-    while (*chr != '\0') {
+    for (; *chr != '\0'; chr++) {
         liquid_crystal_write_char(*chr);
     }
 }
 
-uint32_t liquid_crystal_display(bool display_on, bool cursor_on, bool blink) {
-    uint8_t value = LIQUID_CRYSTAL_CMD_DISPLAY;
-
-    value |= display_on ? 0x04 : 0x00;
-    value |= cursor_on ? 0x02 : 0x00;
-    value |= blink ? 0x01 : 0x00;
-
-    write_value(value, false);
-
-    return NRF_SUCCESS;
+void liquid_crystal_clear() {
+    // The documentation doesn't specify a value, but everything else is 37us
+    write_value(LIQUID_CRYSTAL_CMD_CLEAR, false, 50);
 }
 
-uint32_t liquid_crystal_init(uint32_t _ticks_per_ms) {
-    ticks_per_ms = _ticks_per_ms;
+void liquid_crystal_return_home() {
+    write_value(LIQUID_CRYSTAL_CMD_RETURN_HOME, false, 2000);
+}
 
-    uint32_t err_code = app_gpiote_user_register(&data.gpio_user_id, 0x0000,
-            0x0000, event_handler);
+static struct {
+    union {
+        uint8_t value;
+        struct {
+            bool shift :1;
+            bool increment :1;
+            int :6;
+        } fields __attribute__((packed));
+    };
+}__attribute__((packed)) entry_mode_state;
+
+void liquid_crystal_entry_mode_set(bool increment, bool shift) {
+    /*
+     uint8_t value = LIQUID_CRYSTAL_CMD_ENTRY_MODE_SET;
+
+     value |= increment ? 0x02 : 0x00;
+     value |= shift ? 0x01 : 0x00;
+
+     write_value(value, false);
+     */
+
+    entry_mode_state.fields.increment = increment;
+    entry_mode_state.fields.shift = shift;
+    write_value(entry_mode_state.value, false, 50);
+}
 
-    if (err_code != NRF_SUCCESS) {
-        return err_code;
-    }
+static struct {
+    union {
+        uint8_t value;
+        struct {
+            bool blink :1;
+            bool cursor_on :1;
+            bool display_on :1;
+            int :5;
+        } fields __attribute__((packed));
+    };
+}__attribute__((packed)) display_state;
+
+void liquid_crystal_display(bool display_on, bool cursor_on, bool blink) {
+    display_state.fields.display_on = display_on;
+    display_state.fields.cursor_on = cursor_on;
+    display_state.fields.blink = blink;
+
+    write_value(display_state.value, false, 50);
+}
 
+static struct {
+    union {
+        uint8_t value;
+        struct {
+            int :2;
+            bool many_dots :1;
+            bool two_line :1;
+            bool data_length :1;
+            int :3;
+        } fields __attribute__((packed));
+    };
+}__attribute__((packed)) function_set_state;
+
+void liquid_crystal_init(bool data_length, bool two_line, bool many_dots) {
     nrf_gpio_cfg_output(data.pin_db4);
     nrf_gpio_cfg_output(data.pin_db5);
     nrf_gpio_cfg_output(data.pin_db6);
@@ -135,7 +142,61 @@ uint32_t liquid_crystal_init(uint32_t _ticks_per_ms) {
     nrf_gpio_cfg_output(data.pin_rs);
     nrf_gpio_cfg_output(data.pin_en);
 
-    begin(data);
+    display_state.value = LIQUID_CRYSTAL_CMD_DISPLAY;
+    entry_mode_state.value = LIQUID_CRYSTAL_CMD_ENTRY_MODE_SET;
+    function_set_state.value = LIQUID_CRYSTAL_CMD_FUNCTION_SET;
+
+    function_set_state.fields.data_length = data_length;
+    function_set_state.fields.two_line = two_line;
+    function_set_state.fields.many_dots = many_dots;
+
+    for (int i = 0; i < 3; i++) {
+        nrf_gpio_pin_set(data.pin_en);
+        nrf_delay_ms(100);
+        nrf_gpio_pin_clear(data.pin_en);
+        nrf_delay_ms(100);
+    }
+
+    // SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
+    // according to datasheet, we need at least 40ms after power rises above 2.7V
+    // before sending commands. Arduino can turn on way before 4.5V so we'll wait 50
+    nrf_delay_ms(50);
+
+    nrf_gpio_pin_clear(data.pin_rs);
+    nrf_gpio_pin_clear(data.pin_en);
+
+    write_4(0x03);
+    nrf_delay_us(4500);
+
+    write_4(0x03);
+    nrf_delay_us(4500);
+
+    write_4(0x03);
+    nrf_delay_us(150);
+
+    write_4(0x02);
+
+    write_value(function_set_state.value, false, 50);
+}
+
+void liquid_crystal_reset() {
+    liquid_crystal_clear();
+    liquid_crystal_return_home();
+    liquid_crystal_entry_mode_set(true, false);
+}
+
+void liquid_crystal_set_cursor(int column, int row) {
+    uint8_t value = LIQUID_CRYSTAL_CMD_SET_DDRAM_ADDDRESS;
+
+    if (row == 1) {
+        value += 0x40;
+    } else if (row == 2) {
+        value += 14;
+    } else if (row == 3) {
+        value += 54;
+    }
+
+    value += column;
 
-    return NRF_SUCCESS;
+    write_value(value, false, 50);
 }