work on the display, brightness adjust, ...

CMakeLists.txt

@@ -10,12 +10,14 @@ set(SOURCE_FILES
         lib/calc.h
         lib/iopins.c
         lib/iopins.h
+        lib/adc.c
+        lib/adc.h
         lib/nsdelay.h
         lib/spi.c
         lib/spi.h
         lib/usart.c
         lib/usart.h
-        )
+        pinout.h)
 
 include_directories(lib
         /usr/avr/include/)

Makefile

@@ -29,6 +29,7 @@ OBJS  = $(BINARY).o
 OBJS += lib/usart.o
 OBJS += lib/iopins.o
 OBJS += lib/spi.o
+OBJS += lib/adc.o
 
 # Dirs with header files
 INCL_DIRS = . lib/

lib/adc.c

@@ -0,0 +1,49 @@
+#include <avr/io.h>
+#include <stdint.h>
+
+#include "calc.h"
+#include "adc.h"
+
+/** Initialize the ADC */
+void adc_init(enum ADC_Prescaller presc)
+{
+	ADCSRA |= presc;  // 128 prescaler -> 125 kHz
+	ADMUX  |= _BV(REFS0);  // Voltage reference
+	sbi(ADCSRA, ADEN);  // Enable ADC
+}
+
+/** Disable ADC */
+void adc_disable(void)
+{
+	cbi(ADCSRA, ADEN);
+}
+
+/** Enable ADC */
+void adc_enable(void)
+{
+	sbi(ADCSRA, ADEN);
+}
+
+static void adc_convert(uint8_t channel)
+{
+	set_low_nibble(ADMUX, channel);  // Select channel to sample
+	sbi(ADMUX, ADLAR);  // Align result to left
+	sbi(ADCSRA, ADSC);  // Start conversion
+
+	while (bit_is_high(ADCSRA, ADSC)); // Wait for it...
+}
+
+/** Sample analog pin with 8-bit precision */
+uint8_t adc_read_byte(uint8_t channel)
+{
+	adc_convert(channel);
+	return ADCH;  // The upper 8 bits of ADC result
+}
+
+
+/** Sample analog pin with 10-bit precision */
+uint16_t adc_read_word(uint8_t channel)
+{
+	adc_convert(channel);
+	return ADCW;  // The whole ADC word (10 bits)
+}

lib/adc.h

@@ -0,0 +1,32 @@
+#pragma once
+
+//
+// Utilities for build-in A/D converter
+//
+
+#include <stdint.h>
+
+enum ADC_Prescaller {
+	ADC_PRESC_2 = 1,
+	ADC_PRESC_4 = 2,
+	ADC_PRESC_8 = 3,
+	ADC_PRESC_16 = 4,
+	ADC_PRESC_32 = 5,
+	ADC_PRESC_64 = 6,
+	ADC_PRESC_128 = 7,
+};
+
+/** Initialize the ADC and enable it */
+void adc_init(enum ADC_Prescaller presc);
+
+/** Disable ADC (for power saving) */
+void adc_disable(void);
+
+/** Enable (already initialized) ADC */
+void adc_enable(void);
+
+/** Sample analog pin with 8-bit precision */
+uint8_t adc_read_byte(uint8_t channel);
+
+/** Sample analog pin with 10-bit precision */
+uint16_t adc_read_word(uint8_t channel);

main.c

@@ -9,37 +9,79 @@
 // Include stuff from the library
 #include "lib/iopins.h"
 #include "lib/usart.h"
+#include "lib/spi.h"
+#include "lib/adc.h"
 
+#include "pinout.h"
 
-// Pins
-#define LED 13
+void setup_io(void)
+{
+	as_output(PIN_DISP_CP);
+	as_output(PIN_DISP_D);
+	as_output(PIN_DISP_STR);
 
+	as_input(PIN_KEY_1);
+	as_input(PIN_KEY_2);
+	as_input(PIN_KEY_3);
+	as_input(PIN_KEY_4);
 
-// UART receive handler
-ISR(USART_RX_vect)
-{
-	// "ECHO" function:
-	uint8_t b = usart_rx();
-	usart_tx(b); // send back
+	as_output(PIN_NEOPIXEL);
+	as_output(PIN_DISP_OE);
+
+	as_input(PIN_PWR_KEY);
+	as_output(PIN_PWR_HOLD);
+
+	// PIN_LIGHT_SENSE is ADC exclusive, needs no config
 }
 
+// --- LED display brightness control ---
+#define DISP_BRIGHTNESS OCR2B
+void setup_pwm(void)
+{
+	// PWM for LED display dimming
+	TCCR2A |= (1 << WGM20) | (1 << WGM21) | (1 << COM2B1);
+	TCCR2B |= (1 << CS20);
+
+	DISP_BRIGHTNESS = 0x7F;
+}
 
 void main()
 {
 	usart_init(BAUD_115200);
 	usart_isr_rx_enable(true); // enable RX interrupt handler
 
-	// configure pins
-	as_output(LED);
+	setup_io();
+	setup_pwm();
+	adc_init(ADC_PRESC_128);
+
+	// SPI conf
+	spi_init_master(SPI_LSB_FIRST,
+					CPOL_1, CPHA_0,
+					SPI_DIV_2);
 
-	// globally enable interrupts (for the USART_RX handler)
+	// globally enable interrupts
 	sei();
 
+	uint8_t cnt = 0;
+
 	while (1) {
-		usart_puts("Hello World!\r\n");
+		pin_down(PIN_DISP_STR);
+		spi_send(cnt);
+		spi_send(cnt);
+		pin_up(PIN_DISP_STR);
+		cnt++;
 
-		pin_toggle(13); // blink the LED
+		_delay_ms(100);
 
-		_delay_ms(500);
+		// Brightness directly proportional to light level
+		DISP_BRIGHTNESS = 255 - adc_read_byte(6);
 	}
 }
+
+// UART receive handler
+ISR(USART_RX_vect)
+{
+	// "ECHO" function:
+	uint8_t b = usart_rx();
+	usart_tx(b); // send back
+}

pinout.h

@@ -0,0 +1,36 @@
+//
+// Created by MightyPork on 2017/06/07.
+//
+
+#ifndef FIRMWARE_PINOUT_H
+#define FIRMWARE_PINOUT_H
+
+// Pinout defs
+#include "lib/iopins.h"
+
+// 74HC4094 chain interface for dual 7seg
+#define PIN_DISP_D   D11 // MOSI
+#define PIN_DISP_CP  D13 // SCK
+#define PIN_DISP_STR D10 // NSS, unused for SPI
+#define PIN_DISP_OE  D3  // SCK
+
+// Touch keys
+#define PIN_KEY_1 A0
+#define PIN_KEY_2 A1
+#define PIN_KEY_3 A2
+#define PIN_KEY_4 A3
+
+// We have a conflict with SPI SCK :(
+//#define PIN_LED D13
+
+// NeoPixel data
+#define PIN_NEOPIXEL D2
+
+// Power
+#define PIN_PWR_KEY A4 // Direct input from the power key, used for power-off
+#define PIN_PWR_HOLD A5 // Hold the buck enabled. Set 0 for shutdown
+
+// Ambient light sensor (Vdd -> 10k -> * -> phototransistor -> GND)
+#define PIN_LIGHT_SENSE A6 // ADC exclusive pin
+
+#endif //FIRMWARE_PINOUT_H