finalise basic functionality

Signed-off-by: Devnol <[email protected]>

Author: Devnol

CMakeLists.txt

@@ -15,11 +15,12 @@ pico_sdk_init()
 add_subdirectory(TOTP-MCU)
 
 add_executable(main
-        main.c
+        main.c 
+        lcd.c
         )
 
 # Pull in our pico_stdlib which aggregates commonly used features
-target_link_libraries(main pico_stdlib hardware_rtc TOTP-MCU)
+target_link_libraries(main pico_stdlib hardware_rtc hardware_i2c TOTP-MCU)
 
 # enable usb output, disable uart output
 pico_enable_stdio_usb(main 1)

lcd.c

@@ -0,0 +1,113 @@
+static int addr = 0x3f; //port i2c port in which the LCD adapter is mapped to. For more info check out pico-examples/i2c/bus_scan
+
+//----------- DO NOT EDIT BELOW THIS LINE (unless you know what you're doing) ------------
+//Code from https://github.com/raspberrypi/pico-examples i2c/lcd_1602_i2c.c
+
+#include "pico/stdlib.h"
+#include "hardware/i2c.h"
+// commands
+const int LCD_CLEARDISPLAY = 0x01;
+const int LCD_RETURNHOME = 0x02;
+const int LCD_ENTRYMODESET = 0x04;
+const int LCD_DISPLAYCONTROL = 0x08;
+const int LCD_CURSORSHIFT = 0x10;
+const int LCD_FUNCTIONSET = 0x20;
+const int LCD_SETCGRAMADDR = 0x40;
+const int LCD_SETDDRAMADDR = 0x80;
+
+// flags for display entry mode
+const int LCD_ENTRYSHIFTINCREMENT = 0x01;
+const int LCD_ENTRYLEFT = 0x02;
+
+// flags for display and cursor control
+const int LCD_BLINKON = 0x01;
+const int LCD_CURSORON = 0x02;
+const int LCD_DISPLAYON = 0x04;
+
+// flags for display and cursor shift
+const int LCD_MOVERIGHT = 0x04;
+const int LCD_DISPLAYMOVE = 0x08;
+
+// flags for function set
+const int LCD_5x10DOTS = 0x04;
+const int LCD_2LINE = 0x08;
+const int LCD_8BITMODE = 0x10;
+
+// flag for backlight control
+const int LCD_BACKLIGHT = 0x08;
+
+const int LCD_ENABLE_BIT = 0x04;
+
+// Modes for lcd_send_byte
+#define LCD_CHARACTER  1
+#define LCD_COMMAND    0
+
+/* Quick helper function for single byte transfers */
+void i2c_write_byte(uint8_t val) {
+#ifdef i2c_default
+    i2c_write_blocking(i2c_default, addr, &val, 1, false);
+#endif
+}
+
+void lcd_toggle_enable(uint8_t val) {
+    // Toggle enable pin on LCD display
+    // We cannot do this too quickly or things don't work
+#define DELAY_US 600
+    sleep_us(DELAY_US);
+    i2c_write_byte(val | LCD_ENABLE_BIT);
+    sleep_us(DELAY_US);
+    i2c_write_byte(val & ~LCD_ENABLE_BIT);
+    sleep_us(DELAY_US);
+}
+
+// The display is sent a byte as two separate nibble transfers
+void lcd_send_byte(uint8_t val, int mode) {
+    uint8_t high = mode | (val & 0xF0) | LCD_BACKLIGHT;
+    uint8_t low = mode | ((val << 4) & 0xF0) | LCD_BACKLIGHT;
+
+    i2c_write_byte(high);
+    lcd_toggle_enable(high);
+    i2c_write_byte(low);
+    lcd_toggle_enable(low);
+}
+
+void lcd_clear(void) {
+    lcd_send_byte(LCD_CLEARDISPLAY, LCD_COMMAND);
+}
+
+
+// go to location on LCD
+void lcd_set_cursor(int line, int position) {
+    int val = (line == 0) ? 0x80 + position : 0xC0 + position;
+    lcd_send_byte(val, LCD_COMMAND);
+}
+
+static void inline lcd_char(char val) {
+    lcd_send_byte(val, LCD_CHARACTER);
+}
+
+void lcd_string(const char *s) {
+    while (*s) {
+        lcd_char(*s++);
+    }
+}
+
+//carriage return + clear of line
+void lcd_cr(int line, int line_length) {
+    lcd_set_cursor(line, 0);
+    for (size_t i = 0; i < line_length; i++) lcd_char(0x20); //fill line with whitespaces
+    lcd_set_cursor(line, 0);
+    
+}
+
+void lcd_init() {
+    lcd_send_byte(0x03, LCD_COMMAND);
+    lcd_send_byte(0x03, LCD_COMMAND);
+    lcd_send_byte(0x03, LCD_COMMAND);
+    lcd_send_byte(0x02, LCD_COMMAND);
+
+    lcd_send_byte(LCD_ENTRYMODESET | LCD_ENTRYLEFT, LCD_COMMAND);
+    lcd_send_byte(LCD_FUNCTIONSET | LCD_2LINE, LCD_COMMAND);
+    lcd_send_byte(LCD_DISPLAYCONTROL | LCD_DISPLAYON, LCD_COMMAND);
+    lcd_clear();
+}

lcd.h

@@ -0,0 +1,11 @@
+#include <inttypes.h>
+
+void i2c_write_byte(uint8_t val);
+void lcd_toggle_enable(uint8_t val);
+void lcd_send_byte(uint8_t val, int mode);
+void lcd_clear(void);
+void lcd_cr(int line, int line_length);
+void lcd_set_cursor(int line, int position);
+static void inline lcd_char(char val);
+void lcd_string(const char *s);
+void lcd_init();

main.c

@@ -1,40 +1,64 @@
 #include <stdio.h>
 #include <time.h>
+#include <string.h>
 #include "token.h"
+#include "lcd.h"
 #include "TOTP-MCU/TOTP.h"
 #include "pico/stdlib.h"
 #include "pico/util/datetime.h"
 #include "hardware/gpio.h"
+#include "hardware/i2c.h"
 #include "hardware/rtc.h"
 
 //----------- DO NOT EDIT ABOVE THIS LINE (unless you know what you're doing)
 
 #define BUTTON_L_PIN 15 // GPIO number for left button
 #define BUTTON_SEL_PIN 14 //GPIO number for select button
 #define BUTTON_R_PIN 13 //GPIO number for right button
+#define MAX_LINES 2 //Rows of LCD
+#define MAX_CHARS 16 //Columns of LCD
 #define TZ_OFFSET 3 //time zone offset, modify to your needs
-#define OTP_INTERVAL 30 //interval between new codes in seconds, usually 30
 
 //----------- DO NOT EDIT BELOW THIS LINE (unless you know what you're doing) ------------
 
+char lcd_content[MAX_CHARS]; //variable for holding LCD text to be printed
+
 int get_number(int min, int def, int max, char label[6]){ //used to ask for time settings on startup
     int curr_num = def;
-    printf("\n");
+    lcd_clear();
+    lcd_set_cursor(0,0);
+    sprintf(lcd_content, "%s:", label);
+    lcd_string(lcd_content);
+    lcd_set_cursor(1,0);
+    sprintf(lcd_content, "%d", curr_num);
+    lcd_string(lcd_content);
     while (gpio_get(BUTTON_SEL_PIN) == 1) { //inverted because it's pulled up internally
-        printf("\r");
-        printf("%s: %d", label, curr_num);
         if (gpio_get(BUTTON_L_PIN) == 0) curr_num--; //inverted because it's pulled up internally
         else if (gpio_get(BUTTON_R_PIN) == 0) curr_num++; //inverted because it's pulled up internally
-        
         if (curr_num < min) curr_num = max;
-        if (curr_num > max) curr_num = min;
+        if (curr_num > max) curr_num = min; 
+
+        if ((gpio_get(BUTTON_L_PIN) == 0) || (gpio_get(BUTTON_R_PIN) == 0)) {
+            lcd_cr(1, MAX_CHARS);
+            sprintf(lcd_content, "%d", curr_num);
+            lcd_string(lcd_content);
+        }
+        
         sleep_ms(150); 
     } return curr_num;
 }
 
 int main() {
+    //init IO
+
     stdio_init_all();
-    //init buttons
+    i2c_init(i2c_default, 100 * 1000);
+    //use pins 4 and 5 for SDA and SCL
+    gpio_set_function(PICO_DEFAULT_I2C_SDA_PIN, GPIO_FUNC_I2C); 
+    gpio_set_function(PICO_DEFAULT_I2C_SCL_PIN, GPIO_FUNC_I2C);
+    gpio_pull_up(PICO_DEFAULT_I2C_SDA_PIN);
+    gpio_pull_up(PICO_DEFAULT_I2C_SCL_PIN);
+
     gpio_init(BUTTON_L_PIN);
     gpio_init(BUTTON_R_PIN);
     gpio_init(BUTTON_SEL_PIN);
@@ -45,7 +69,15 @@ int main() {
     gpio_set_dir(BUTTON_R_PIN, GPIO_IN);
     gpio_set_dir(BUTTON_SEL_PIN, GPIO_IN);
 
-    ////obtain date and time
+    lcd_init();
+    lcd_set_cursor(0, 0);
+    lcd_string("TOTP Token");
+    lcd_set_cursor(1,0);
+    lcd_string("By Devnol");
+    sleep_ms(1000);
+    
+
+    //obtain date and time
 
         int year = get_number(0, 2021, 4095, "Year");
         sleep_ms(400);
@@ -104,7 +136,8 @@ int main() {
 
     //instantiate TOTP library
     TOTP(hmacKey, HMAC_KEY_LENGTH, OTP_INTERVAL);
-
+    lcd_clear();
+    lcd_set_cursor(0,0);
     //main Token generation loop
     while (true) {
         rtc_get_datetime(&t);
@@ -114,8 +147,10 @@ int main() {
         }
         strptime(datetime_str, "%A %d %b %H:%M:%S %Y", &tm);
         uint32_t newCode = getCodeFromTimestamp(epoch);
-        printf("Token: %d\n", newCode);
-        sleep_ms(1000);
+        lcd_cr(0, MAX_CHARS);    
+        sprintf(lcd_content, "Token: %d", newCode);
+        lcd_string(lcd_content);
+        sleep_ms(5000);
     }
     return 0;    
 }