mirror of
https://github.com/mytechnotalent/Embedded-Hacking.git
synced 2026-07-18 18:07:30 +02:00
Kevin Thomas
118 lines
3.2 KiB
C
118 lines
3.2 KiB
C
/**
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******************************************************************************
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* @file main.c
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* @author Kevin Thomas
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* @brief LCD1602 demonstration: static title and live counter display.
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*
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* Drives a 16x2 HD44780 LCD via a PCF8574 I2C backpack. Line 0
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* shows a static title ("Reverse Eng.") and line 1 displays a
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* counter that increments every second. The counter value is
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* also printed over UART for debugging.
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*
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* Wiring:
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* GPIO0 -> UART TX (USB-to-UART adapter RX)
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* GPIO1 -> UART RX (USB-to-UART adapter TX)
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* GPIO2 -> PCF8574 backpack SDA (4.7 kohm pull-up to 3.3 V)
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* GPIO3 -> PCF8574 backpack SCL (4.7 kohm pull-up to 3.3 V)
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* 3.3V -> PCF8574 backpack VCC
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* GND -> PCF8574 backpack GND
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*
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******************************************************************************
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* @attention
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*
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* Copyright (c) 2026 Kevin Thomas.
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* All rights reserved.
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*
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* This software is licensed under terms that can be found in the LICENSE file
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* in the root directory of this software component.
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* If no LICENSE file comes with this software, it is provided AS-IS.
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*
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******************************************************************************
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*/
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#include "rp2350_i2c.h"
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#include "rp2350_lcd1602.h"
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#include "rp2350_uart.h"
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#include "rp2350_xosc.h"
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#include "rp2350_delay.h"
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#define COUNT_DELAY_MS 1000
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/**
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* @brief Convert an unsigned 32-bit integer to a decimal string.
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*
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* Writes at most 10 decimal digits plus a null terminator
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* into the provided buffer. The buffer must be at least
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* 11 bytes.
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*
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* @param val value to convert
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* @param buf destination buffer (minimum 11 bytes)
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* @retval None
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*/
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static void _uint_to_str(uint32_t val, char *buf)
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{
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char tmp[11];
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int i = 0;
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if (val == 0) {
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buf[0] = '0';
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buf[1] = '\0';
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return;
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}
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while (val > 0) {
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tmp[i++] = (char)('0' + (val % 10));
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val /= 10;
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}
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for (int j = 0; j < i; j++)
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buf[j] = tmp[i - 1 - j];
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buf[i] = '\0';
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}
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/**
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* @brief Format "Count: " followed by a right-justified counter value.
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*
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* Writes the formatted string into a 17-byte buffer and pads
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* with spaces to fill the 16-column display width.
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*
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* @param count current counter value
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* @param buf destination buffer (minimum 17 bytes)
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* @retval None
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*/
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static void _format_counter(uint32_t count, char *buf)
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{
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char num[11];
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_uint_to_str(count, num);
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const char *prefix = "Count: ";
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int i = 0;
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while (prefix[i]) { buf[i] = prefix[i]; i++; }
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int j = 0;
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while (num[j]) buf[i++] = num[j++];
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while (i < 16) buf[i++] = ' ';
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buf[i] = '\0';
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}
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/**
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* @brief Application entry point for the LCD 1602 counter demo.
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* @retval int does not return
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*/
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int main(void)
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{
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xosc_set_clk_ref();
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i2c_release_reset();
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i2c_init();
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lcd_init();
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uart_puts("LCD 1602 driver initialized at I2C addr 0x27\r\n");
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lcd_set_cursor(0, 0);
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lcd_puts("Reverse Eng.");
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uint32_t count = 0;
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while (1) {
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char buf[17];
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_format_counter(count, buf);
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lcd_set_cursor(1, 0);
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lcd_puts(buf);
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uart_puts(buf);
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uart_puts("\r\n");
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count++;
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delay_ms(COUNT_DELAY_MS);
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}
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}
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