From 3fb309951f0c2ca6f516f854f1ab942179f28b47 Mon Sep 17 00:00:00 2001
From: Rutherther <rutherther@ditigal.xyz>
Date: Thu, 28 Nov 2024 15:44:05 +0100
Subject: [PATCH] feat(arm03): implement display
---
arm03/include/display.h | 44 +++++++++++++
arm03/src/display.c | 139 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 183 insertions(+)
create mode 100644 arm03/include/display.h
create mode 100644 arm03/src/display.c
diff --git a/arm03/include/display.h b/arm03/include/display.h
new file mode 100644
index 0000000..5aec4cc
--- /dev/null
+++ b/arm03/include/display.h
@@ -0,0 +1,44 @@
+#include <stdint.h>
+#include "pin.h"
+
+#ifndef DISPLAY_H
+#define DISPLAY_H
+
+typedef struct {
+ // Display board configuration
+ uint16_t digits_count;
+ pin_t pin_data;
+ pin_t pin_sftclk;
+ pin_t pin_strobe;
+
+ // Current application data
+ uint32_t bcd_digits;
+ uint8_t digit_dots;
+
+ // Current application state
+ uint8_t digits_en;
+
+ // Current internal state of the display
+ uint16_t current_cycle;
+ uint32_t current_shifter;
+ uint8_t current_digit;
+ uint16_t max_value;
+} display_t;
+
+typedef enum {
+ DISPLAY_UPDATE_NEW_DIGIT,
+ DISPLAY_UPDATE_DISPLAY_DIGIT,
+ DISPLAY_UPDATE_SHIFT,
+} display_update_state_t;
+
+void display_init(display_t* display, uint16_t digits, pin_t pin_data, pin_t pin_sftclk, pin_t pin_strobe);
+
+void display_convert_number(display_t* display, uint32_t number);
+void display_digit_set(display_t* display, uint8_t digit, uint8_t number);
+
+void display_dots(display_t* display, uint8_t dots);
+void display_enable_digit(display_t* display, uint8_t digit, uint8_t enable);
+
+display_update_state_t display_update(display_t* display);
+
+#endif // DISPLAY_H
diff --git a/arm03/src/display.c b/arm03/src/display.c
new file mode 100644
index 0000000..4c77e5e
--- /dev/null
+++ b/arm03/src/display.c
@@ -0,0 +1,139 @@
+#include "display.h"
+#include "registers.h"
+
+#define CYCLES 17
+
+const char numbers_seven_segments[11] = {
+ 0x3F, /* 0 */
+ 0x06, /* 1 */
+ 0x5B, /* 2 */
+ 0x4F, /* 3 */
+ 0x66, /* 4 */
+ 0x6D, /* 5 */
+ 0x7D, /* 6 */
+ 0x07, /* 7 */
+ 0x7F, /* 8 */
+ 0x6F, /* 9 */
+ 0x40, /* - */
+};
+
+uint16_t pow16(uint16_t num, uint8_t pow) {
+ for (uint16_t i = 0; i < pow; i++) {
+ num *= num;
+ }
+ return num;
+}
+
+
+void display_init(display_t *display, uint16_t digits, pin_t pin_data,
+ pin_t pin_sftclk, pin_t pin_strobe) {
+ display->digits_count = digits;
+ display->bcd_digits = 0;
+
+ display->digits_en = ~0;
+ display->digit_dots = ~0;
+
+ display->pin_data = pin_data;
+ display->pin_sftclk = pin_sftclk;
+ display->pin_strobe = pin_strobe;
+
+ display->max_value = pow16(10, digits);
+ display->current_cycle = 0;
+ display->current_shifter = 0;
+ display->current_digit = 0;
+}
+
+/**
+ * @brief Convert a digit from a regular number to seven segments
+ * @param[in] number The number to convert
+ * @param[in] digit The digit from least significant, starting with 0
+ * @return Description
+ */
+uint16_t seven_segment_convert(uint16_t number, uint16_t digit, uint8_t dot);
+
+/**
+ * @brief Converts a number to serial strem to send via the SIPO register.
+ * @param[in] number The bcd number to convert to the values for shift register
+ * @param[in] digit The digit from the least significant, starting with 0
+ * @return Description
+ */
+uint16_t convert_num_digit(uint16_t bcd_number, uint8_t digits_count, uint8_t digit, uint8_t dot);
+
+uint16_t seven_segment_convert(uint16_t bcd_number, uint16_t digit, uint8_t dot) {
+ return ~(numbers_seven_segments[(bcd_number >> (digit << 2)) & 0xF] | dot << 7);
+}
+
+uint16_t convert_num_digit(uint16_t number, uint8_t digits_count, uint8_t digit, uint8_t dot) {
+ uint16_t seven_segments = seven_segment_convert(number, digits_count - 1 - digit, dot);
+ uint16_t digits = 1 << digit;
+
+ return (seven_segments << 8) | digits;
+}
+
+void display_dots(display_t* display, uint8_t dots) {
+ display->digit_dots = dots;
+}
+
+void display_convert_number(display_t *display, uint32_t number) {
+ uint32_t bcd = 0;
+ for (uint8_t i = 0; i < display->digits_count; i++) {
+ bcd |= (number % 10) << (i << 2);
+ number /= 10;
+ }
+ display->bcd_digits = bcd;
+}
+
+void display_enable_digit(display_t *display, uint8_t digit, uint8_t enable) {
+ uint16_t digits = 1 << digit;
+ if (enable != 0) {
+ display->digits_en |= digits;
+ } else {
+ display->digits_en &= ~digits;
+ }
+}
+
+void display_digit_set(display_t *display, uint8_t digit, uint8_t number) {
+ reg_write_bits_pos(&display->bcd_digits, number, digit << 2, 0xF);
+}
+
+display_update_state_t display_update(display_t *display) {
+ display_update_state_t state = DISPLAY_UPDATE_SHIFT;
+
+ if (display->current_cycle == 0) {
+ // Set up.
+ display->current_digit = (display->current_digit + 1) % display->digits_count;
+
+ if (display->digits_en & (1 << display->current_digit)) {
+ display->current_shifter = convert_num_digit(
+ display->bcd_digits, display->digits_count, display->current_digit,
+ (display->digit_dots >> display->current_digit) & 1);
+ } else {
+ // Still send the data even for disabled digits,
+ // to prevent display having different brightness
+ // depending on how many digits are currently on.
+ display->current_shifter = 0;
+ }
+
+ state = DISPLAY_UPDATE_NEW_DIGIT;
+ }
+
+ if (display->current_cycle < CYCLES - 1) {
+ pin_write(&display->pin_data,
+ reg_read_bits_pos(&display->current_shifter,
+ 15 - display->current_cycle,
+ 1));
+
+ pin_set(&display->pin_sftclk);
+ pin_reset(&display->pin_sftclk);
+ } else {
+ // Send strobe
+ pin_set(&display->pin_strobe);
+ pin_reset(&display->pin_strobe);
+
+ state = DISPLAY_UPDATE_DISPLAY_DIGIT;
+ }
+
+ display->current_cycle = (display->current_cycle + 1) % CYCLES;
+
+ return state;
+}
--
2.48.1