Enable storing LED brightness in EEPROM

firmware/config.c

@@ -0,0 +1,41 @@
+#include "config.h"
+
+struct CFG ram_cfg;
+struct CFG eem_cfg EEMEM;
+const struct CFG pgm_cfg PROGMEM = {
+  LED_BRIGHTNESS
+};
+
+void map_eem2ram(void)
+{
+  eeprom_read_block(&ram_cfg, &eem_cfg, sizeof(ram_cfg));
+}
+
+void map_pgm2ram(void)
+{
+  memcpy_P(&ram_cfg, &pgm_cfg, sizeof(ram_cfg));
+}
+
+void dump_ram2eem(void)
+{
+  eeprom_write_block(&ram_cfg, &eem_cfg, sizeof(ram_cfg));
+}
+
+void load_defaults(void)
+{
+  map_pgm2ram();
+  dump_ram2eem();
+}
+
+void cfg_init(void)
+{
+  uint8_t i;
+  uint8_t len = sizeof(ram_cfg);
+  uint8_t* ram_cfg_byte = (uint8_t*) &ram_cfg;
+
+  map_eem2ram();
+
+  for(i=0; i<len; ++i) if(*ram_cfg_byte++ != 0xFF) break;
+  
+  if(i == len) load_defaults();
+}

firmware/config.h

@@ -0,0 +1,24 @@
+#ifndef __CONFIG_H__
+#define __CONFIG_H__
+
+#include <avr/eeprom.h>
+#include <avr/pgmspace.h>
+
+#define LED_BRIGHTNESS 127
+
+struct CFG
+{
+  uint8_t led_brightness;
+};
+
+extern struct CFG ram_cfg;
+extern struct CFG eem_cfg EEMEM;
+extern const struct CFG pgm_cfg PROGMEM;
+
+void map_eem2ram(void);
+void map_pgm2ram(void);
+void dump_ram2eem(void);
+void load_defaults(void);
+void cfg_init(void);
+
+#endif

firmware/keyboard.c

@@ -1,4 +1,5 @@
 #include <avr/io.h>
+#include "config.h"
 #include "keyboard.h"
 #include "debounce.h"
 #include "rtc.h"
@@ -26,8 +27,9 @@ void inc_second(void)
 
 void inc_brightness(void)
 {
-  led_brightness <<= 1;
-  if(!led_brightness) led_brightness = 1;
+  ram_cfg.led_brightness <<= 1;
+  if(!ram_cfg.led_brightness) ram_cfg.led_brightness = 1;
+  dump_ram2eem();
 }
 
 void keyboard_init(void)

firmware/led.c

@@ -1,8 +1,8 @@
 #include <avr/io.h>
 #include <avr/interrupt.h>
+#include "config.h"
 #include "led.h"
 
-volatile uint8_t led_brightness = 1;
 volatile uint8_t led_hour;
 volatile uint8_t led_minute;
 volatile uint8_t led_second;
@@ -32,15 +32,15 @@ ISR(TIMER0_OVF_vect)
     {
       case 1: 
         LED_PORT = ~led_hour;   
-        ANODES_PORT = led_brightness >= pwm_counter ? ~HOUR_ANODE : 0xFF;
+        ANODES_PORT = ram_cfg.led_brightness >= pwm_counter ? ~HOUR_ANODE : 0xFF;
         break;
       case 2: 
         LED_PORT = ~led_minute;   
-        ANODES_PORT = led_brightness >= pwm_counter ? ~MINUTE_ANODE : 0xFF;  
+        ANODES_PORT = ram_cfg.led_brightness >= pwm_counter ? ~MINUTE_ANODE : 0xFF;  
         break;
       case 4: 
         LED_PORT = ~led_second;
-        ANODES_PORT = led_brightness >= pwm_counter ? ~SECOND_ANODE : 0xFF; 
+        ANODES_PORT = ram_cfg.led_brightness >= pwm_counter ? ~SECOND_ANODE : 0xFF; 
         break;
     }
 

firmware/led.h

@@ -10,7 +10,6 @@
 #define MINUTE_ANODE (1<<PD6)
 #define SECOND_ANODE (1<<PD7)
 
-extern volatile uint8_t led_brightness;
 extern volatile uint8_t led_hour;
 extern volatile uint8_t led_minute;
 extern volatile uint8_t led_second;

firmware/main.c

@@ -1,5 +1,6 @@
 #include <avr/io.h>
 #include <avr/interrupt.h>
+#include "config.h"
 #include "keyboard.h"
 #include "ptimer.h"
 #include "i2c.h"
@@ -10,6 +11,7 @@
 
 int main() 
 {
+  cfg_init();
   keyboard_init();
   ptimer_init();
   i2c_init(I2C_BITRATE);