Style fixes and added some comments

README.md

@@ -0,0 +1,41 @@
+# I237 Hardware Programming
+
+This here is my repository for hardware programming course at
+Estonian IT College that is based around a
+[Arduino Mega 2560](https://www.arduino.cc/en/Main/ArduinoBoardMega2560).
+
+This code us usualy updated once every two weeks when a new excersice is put up
+by Silver Kits.
+
+# How to install
+
+Currently to test this code you have to clone the repository
+
+```bash
+git clone https://git.wut.ee/arti/i237.git hardware
+cd hardware
+```
+
+And export a enviroment variable that points to a Arduino Mega board. The
+real path will depend on the OS and Computer that you are using. For me it is
+usualy `/dev/ttyACM0`.
+
+```bash
+export ARDUINO=/dev/ttyACM0
+```
+
+After that you can `make` the project.
+
+```bash
+make clean
+make
+make install
+```
+
+You can also chekcout previous labs using `git checkout <lab name>`. For example
+
+```bash
+git checkout lab02
+```
+
+Don't forget to `make clean` after each checkout!

doc/arduino-mega-lcd1602-keypad-shield-wiring.markdown

@@ -10,9 +10,21 @@ This shield consists of three logical parts:
 
 <div class=pagebreak></div>
 
+## Connection to Arduino Mega
+
+Following illustration shows how shield is connected to Arduino mega board.
+
+![arduino-mega-lcd1602-keypad-shield-placement.png](arduino-mega-lcd1602-keypad-shield-placement.png)
+
+Image source: [sainsmart.com](http://www.sainsmart.com/media/catalog/product/2/_/2_16_6.jpg)
+
+Additional installation details and tutorials can be found with help of keywords [Arduino 1602 lcd keypad shield tutorial](https://www.google.ee/webhp?q=Arduino+1602+lcd+keypad+shield+tutorial).
+
+<div class=pagebreak></div>
+
 ## Wiring illustration
 
-![Arduino Mega LCD1602 Keypad shield wiring LCD part.png](Arduino-Mega-LCD1602-keypad-shield-wiring.png)
+![arduino-mega-lcd1602-keypad-shield-wiring.png](arduino-mega-lcd1602-keypad-shield-wiring.png)
 
 Author: [Lauri Võsandi](http://lauri.võsandi.com/arduino/lcd1602-key-shield.html#hd44780)
 

doc/arduino-mega-usb-uart-wiring.markdown

@@ -6,12 +6,12 @@ This wiring schema uses only Tx from Arduino and is suitable to be used as stand
 
 ## Wiring illustration
 
-![Arduino Mega USB UART wiring.png](Arduino-Mega-USB-UART-wiring.png)
+![arduino-mega-usb-uart-wiring.png](arduino-mega-usb-uart-wiring.png)
 
 ## Wiring table
 
 | Signal | ATMega2560 port and pin | Arduino Mega 2560 pin | USB UART converter pin |
 | --- | --- | --- | --- |
 | Ground (GND) | GND | GND | GND |
-| Transmit data  from Arduino (TxD) | PORTJ pin 1 (TXD3) | Digital pin 14 (TX3) | TxD |
+| Transmit data  from Arduino (TxD) | PORTJ pin 1 (TXD3) | Digital pin 14 (TX3) | RxD |
 

src/hmi_msg.h

@@ -0,0 +1,19 @@
+#include <avr/pgmspace.h>
+#ifndef _HMI_MSG_H_
+#define _HMI_MSG_H_
+
+#define PROG_VERSION "Version: %S built on: %S %S"
+#define LIBC_VERSION "avr-libc version: %S"
+#define STUD_NAME "Arti Zirk"
+#define GET_MONTH_MSG "Enter Month name first letter >"
+#define UPTIME_MSG "Uptime: %lu s"
+
+const char m1[] PROGMEM = "January";
+const char m2[] PROGMEM = "February";
+const char m3[] PROGMEM = "March";
+const char m4[] PROGMEM = "April";
+const char m5[] PROGMEM = "May";
+const char m6[] PROGMEM = "June";
+
+PGM_P const months[] PROGMEM = {m1,m2,m3,m4,m5,m6};
+#endif /* _HMI_MSG_H_ */

src/main.c

@@ -0,0 +1,128 @@
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <avr/pgmspace.h>
+#include <util/delay.h>
+#include "hmi_msg.h"
+#include "../lib/andygock_avr-uart/uart.h"
+#include "uart_wrap.h"
+#include "print_helper.h"
+#include "../lib/hd44780_111/hd44780.h"
+
+#define BAUDRATE 9600
+
+// For configuring arduino mega pin 25
+#define LED_INIT DDRA |= _BV(DDA3);
+#define LED_TOGGLE PORTA ^= _BV(PORTA3)
+
+static inline void init_system_clock(void)
+{
+    TCCR5A = 0; // Clear control register A
+    TCCR5B = 0; // Clear control register B
+    TCCR5B |= _BV(WGM52) | _BV(CS52); // CTC and fCPU/256
+    OCR5A = 62549; // 1 s
+    TIMSK5 |= _BV(OCIE5A); // Output Compare A Match Interrupt Enable
+}
+
+static inline void init_hw (void)
+{
+    // IO init
+    /// Set arduino pin 25 as output
+    LED_INIT;
+
+    // System clock
+    init_system_clock();
+
+    // UART init
+    uart0_init(UART_BAUD_SELECT(BAUDRATE, F_CPU));
+    uart3_init(UART_BAUD_SELECT(BAUDRATE, F_CPU));
+    stdout = stdin = &uart0_io;
+    stderr = &uart3_out;
+
+    // LCD init
+    lcd_init();
+    lcd_clrscr();
+
+    // Enable interupts
+    sei();
+}
+
+static inline void start_ui (void)
+{
+    // Print program and libc versions
+    fprintf_P(stderr, PSTR(PROG_VERSION "\n"),
+              PSTR(GIT_DESCR), PSTR(__DATE__), PSTR(__TIME__));
+    fprintf_P(stderr, PSTR(LIBC_VERSION "\n"), PSTR(__AVR_LIBC_VERSION_STRING__));
+
+    // print student name
+    fprintf_P(stdout, PSTR(STUD_NAME));
+    fputc('\n', stdout); // Add a new line to the uart printout
+    lcd_puts_P(PSTR(STUD_NAME));
+
+    // ASCII table print
+    print_ascii_tbl(stdout);
+    unsigned char ascii[128];
+    for (unsigned char i = 0; i < sizeof(ascii); i++) {
+        ascii[i] = i;
+    }
+    print_for_human(stdout, ascii, sizeof(ascii));
+
+    // Bootstrap search_month message
+    fprintf_P(stdout, PSTR(GET_MONTH_MSG));
+}
+
+static inline void search_month (void)
+{
+    char letter;
+
+    fscanf(stdin, "%c", &letter);
+    fprintf(stdout, "%c\n", letter);
+    lcd_goto(0x40); // Got to the beginning of the next line
+    for (int i = 0; i < 6; i++) {
+        if (!strncmp_P(&letter, (PGM_P)pgm_read_word(&months[i]), 1)) {
+            fprintf_P(stdout, (PGM_P)pgm_read_word(&months[i]));
+            fputc('\n', stdout);
+            lcd_puts_P((PGM_P)pgm_read_word(&months[i]));
+            lcd_putc(' ');
+        }
+    }
+
+    // this is fine because even when the hd44780 address counter goes over 0xf4
+    // we still have quite a few addresses left until address counter overflow
+    // and we also dont care about the data that is at the end of the ddram
+    lcd_puts_P(PSTR("                ")); // Clear the end of the line
+    fprintf_P(stdout, PSTR(GET_MONTH_MSG));
+}
+
+static inline void heartbeat (void)
+{
+    static time_t time_prev;
+    time_t time_cur = time(NULL);
+    if (time_cur <= time_prev) {
+        return;
+    }
+    time_prev = time_cur;
+    fprintf_P(stderr, PSTR(UPTIME_MSG "\n"), time_cur);
+    LED_TOGGLE;
+}
+
+int main (void)
+{
+    init_hw();
+    start_ui();
+
+    while (1) {
+        heartbeat();
+        if (uart0_available()) {
+            search_month();
+        }
+    }
+}
+
+// System clock
+ISR(TIMER5_COMPA_vect)
+{
+    system_tick();
+}

src/print_helper.c

@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <avr/pgmspace.h>
+#include "print_helper.h"
+
+int print_ascii_tbl (FILE *stream)
+{
+    for (char c = ' '; c <= '~'; c++) {
+        if (!fprintf(stream, "%c ", c)) {
+            return 0;
+        }
+    }
+
+    return fprintf(stream, "\n");
+}
+
+
+int print_for_human (FILE *stream, const unsigned char *array, const int len)
+{
+    for (int i = 0; i < len; i++) {
+        unsigned char c = array[i];
+        if (c >= ' ' && c <= '~') {
+            if (!fprintf(stream, "%c", c)) {
+                return 0;
+            }
+        } else {
+            if (!fprintf(stream, "\"0x%02x\"", c)) {
+                return 0;
+            }
+        }
+    }
+
+    return fprintf(stream, "\n");
+}

src/print_helper.h

@@ -0,0 +1,7 @@
+#ifndef _PRINT_HELPER_H_
+#define _PRINT_HELPER_H_
+
+int print_ascii_tbl (FILE *stream);
+int print_for_human (FILE *stream, const unsigned char *array, const int len);
+
+#endif /* _PRINT_HELPER_H_ */

src/uart_wrap.c

@@ -0,0 +1,37 @@
+#include <avr/io.h>
+#include <stdio.h>
+#include "../lib/andygock_avr-uart/uart.h"
+
+int uart0_putc_wrap(char c, FILE *stream)
+{
+    (void) stream;
+
+    if (c == '\n') {
+        uart0_putc_wrap('\r', stream);
+    }
+
+    uart0_putc(c);
+    return 0;
+}
+
+int uart0_getc_wrap(FILE *stream)
+{
+    (void) stream;
+    // Probabbly should add some error checking in here but because
+    // this function is only called out when there is at least one character
+    // available in the input buffer (see main.c line 114) then error checking
+    // is not currently necessary.
+    return (char)uart0_getc();
+}
+
+int uart3_putc_wrap(char c, FILE *stream)
+{
+    (void) stream;
+
+    if (c == '\n') {
+        uart3_putc_wrap('\r', stream);
+    }
+
+    uart3_putc(c);
+    return 0;
+}

src/uart_wrap.h

@@ -0,0 +1,15 @@
+#ifndef _UART_WRAP_H_
+#define _UART_WRAP_H_
+
+int uart0_putc_wrap(char c, FILE *stream);
+int uart0_getc_wrap(FILE *stream);
+
+int uart3_putc_wrap(char c, FILE *stream);
+
+
+/* http://www.ermicro.com/blog/?p=325 */
+
+FILE uart0_io = FDEV_SETUP_STREAM(uart0_putc_wrap, uart0_getc_wrap, _FDEV_SETUP_RW);
+FILE uart3_out = FDEV_SETUP_STREAM(uart3_putc_wrap, NULL, _FDEV_SETUP_WRITE);
+
+#endif /* _UART_WRAP_H_ */

tooling/format-code.sh

@@ -18,10 +18,8 @@ for FILE in "$@"
 do
     RESULT="$(astyle    --style=1tbs \
                         --indent-col1-comments \
-                        --break-blocks \
                         --pad-oper \
                         --pad-header \
-                        --delete-empty-lines \
                         --add-brackets \
                         --convert-tabs \
                         --max-code-length=80 \