Restructure code a bit

9 files changed, 298 insertions, 136 deletions

diff --git a/.gitignore b/.gitignore
index 6769eb2..39274f6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,11 @@
 *.o
-*.flash
-*.eeprom
-*.map
+*.elf
+*.eep
+*.lss
+*.lst
 *.orig
+*.hex
+*.sym
+*.map
 *.?#?
+/.dep
diff --git a/Makefile b/Makefile
index 4adeef6..e7d7a19 100644
--- a/Makefile
+++ b/Makefile
@@ -73,7 +73,7 @@ FORMAT = ihex
 
 
 # Target file name (without extension).
-TARGET = ferment
+TARGET = main
 
 
 # Object files directory
diff --git a/bridge.c b/bridge.c
new file mode 100644
index 0000000..5f1806b
--- /dev/null
+++ b/bridge.c
@@ -0,0 +1,72 @@
+#include <avr/io.h>
+#include <util/delay.h>
+
+#include "bridge.h"
+
+/* port D
+ *
+ *  4 1- (NMOS, inverted) 
+ *  5 1+ (PMOS)
+ *  6 2- (NMOS, inverted)
+ *  7 2+ (PMOS)
+ *
+ */
+
+#define D_1_MINUS	(1 << 4)
+#define D_1_PLUS	(1 << 5)
+#define D_2_MINUS	(1 << 6)
+#define D_2_PLUS	(1 << 7)
+
+enum bridge_state {
+	BRIDGE_OFF,
+	BRIDGE_HEATING,
+	BRIDGE_COOLING
+};
+
+static enum bridge_state bridge_state;
+
+/* Turns the H-bridge off, putting the output
+ * into high impedance mode. */
+void bridge_off(void)
+{
+	if (bridge_state == BRIDGE_OFF)
+		return;
+
+	PORTD |= D_1_MINUS | D_2_MINUS;
+	PORTD &= ~(D_1_PLUS | D_2_PLUS);
+	_delay_ms(100);
+	bridge_state = BRIDGE_OFF;
+}
+
+/* Turns the H-bridge on, setting 1+ 2- */
+void bridge_on_heat(void)
+{
+	if (bridge_state == BRIDGE_HEATING)
+		return;
+
+	bridge_off();
+	bridge_state = BRIDGE_HEATING;
+	PORTD |= D_1_PLUS;
+	PORTD &= ~D_2_MINUS;
+}
+
+/* Turns the H-bridge on, setting 1- 2+ */
+void bridge_on_cool(void)
+{
+	if (bridge_state == BRIDGE_COOLING)
+		return;
+
+	bridge_off();
+	bridge_state = BRIDGE_COOLING;
+	PORTD |= D_2_PLUS;
+	PORTD &= ~D_1_MINUS;
+}
+
+/* Initializes the output port needed for the H-bridge */
+void bridge_init(void)
+{
+	PORTD |= D_1_MINUS | D_2_MINUS;
+	PORTD &= ~(D_1_PLUS | D_2_PLUS);
+	DDRD |= D_1_PLUS | D_1_MINUS | D_2_PLUS | D_2_MINUS;
+	bridge_state = BRIDGE_OFF;
+}
diff --git a/bridge.h b/bridge.h
new file mode 100644
index 0000000..21bbfc3
--- /dev/null
+++ b/bridge.h
@@ -0,0 +1,9 @@
+#ifndef BRIDGE_H
+#define BRIDGE_H
+
+void bridge_off(void);
+void bridge_on_heat(void);
+void bridge_on_cool(void);
+void bridge_init(void);
+
+#endif
diff --git a/command.c b/command.c
index 41472c7..7d8c515 100644
--- a/command.c
+++ b/command.c
@@ -1,10 +1,88 @@
 #include <avr/io.h>
 #include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
+#include "controller.h"
 #include "serial.h"
 
-uint16_t serial_rx_cb(char *buffer, uint16_t len)
+static void handle_set(char *buffer, uint16_t len)
 {
-	return 1;
+	const char *error_msg = "ERR Invalid number for temperature\r\n";
+	const char *error_msg2 = "ERR Temperature out of range.\r\n";
+	const char *success_msg = "OK Temperature set.\r\n";
+	const char *input;
+	char *endptr;
+	long temperature;
+
+	if (len < 2) {
+		serial_send(error_msg, strlen(error_msg), 0);
+		return;
+	}
+
+	input = buffer + 1;
+	temperature = strtol(input, &endptr, 10);
+	if (input[0] == '\r' || input[0] == '\n' ||
+			(endptr[0] != '\r' && endptr[0] != '\n')) {
+		serial_send(error_msg, strlen(error_msg), 0);
+		return;
+	}
+
+	if (controller_set(temperature)) {
+		serial_send(error_msg2, strlen(error_msg2), 0);
+		return;
+	}
+
+	serial_send(success_msg, strlen(success_msg), 0);
 }
 
+static void handle_off(char *buffer, uint16_t len)
+{
+	const char *success_msg = "OK Powered down.\r\n";
+	
+	controller_off();
+	serial_send(success_msg, strlen(success_msg), 0);
+}
+
+static void handle_get(char *buffer, uint16_t len)
+{
+	char response[128];
+
+	snprintf(response, sizeof(response), "OK t=%ld\r\n", controller_get());
+	serial_send(response, strlen(response), 0);
+}
+
+uint16_t serial_rx_cb(char *buffer, uint16_t len)
+{
+	const char *error_msg = "ERR Unknown command\r\n";
+	switch(buffer[len-1]) {
+	case '\r':
+	case '\n':
+		serial_send("\r\n", 2, 0);
+		break;
+	default:
+		/* If we didn't get a line break, just echo and return */
+		serial_send(&buffer[len-1], 1, 0);
+		return 0;
+	}
+
+	switch(buffer[0]) {
+	case 's':
+	case 'S':
+		handle_set(buffer, len);
+		break;
+	case 'g':
+	case 'G':
+		handle_get(buffer, len);
+		break;
+	case 'o':
+	case 'O':
+		handle_off(buffer, len);
+		break;
+	default:
+		serial_send(error_msg, strlen(error_msg), 0);
+	}
+
+	return len;
+}
diff --git a/controller.c b/controller.c
new file mode 100644
index 0000000..29ac0ab
--- /dev/null
+++ b/controller.c
@@ -0,0 +1,105 @@
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+#include "controller.h"
+
+#include "bridge.h"
+
+static void adc_init(void)
+{
+	/* Configure the ADC */
+	ADMUX = (1 << REFS1) | (1 << REFS0);
+	/* select channel x (0 for now) */
+	ADMUX |= 0x0;
+	ADCSRA = (1 << ADEN) | (1 << ADIE)
+		| (1 << ADPS2) | (1 << ADPS1)
+		| (1 << ADPS0);
+}
+
+/* Initializes TIMER1 */
+static void timer_init(void)
+{
+	TCCR1B = (1 << WGM12) | (1 << CS12) | (1 << CS10);
+	OCR1A = 7200;
+	TIMSK|=(1<<OCIE1A);
+}
+
+static volatile char controller_in_init;
+static volatile char controller_active;
+static volatile long controller_target_temp;
+static volatile char controller_num_iterations;
+static volatile uint16_t controller_measured_temp;
+
+void controller_init(void)
+{
+	controller_active = 0;
+	controller_in_init = 1;
+
+	bridge_init();
+	adc_init();
+	timer_init();
+}
+
+int controller_set(long target)
+{
+	if (target < 50 || target > 974)
+		return 1;
+
+	controller_target_temp = target;
+	controller_num_iterations = 1;
+	controller_active = 1;
+	return 0;
+}
+
+long controller_get(void)
+{
+	return controller_measured_temp;
+}
+
+void controller_off(void)
+{
+	controller_active = 0;
+	bridge_off();
+}
+
+ISR(TIMER1_COMPA_vect)
+{
+	/* Start adc measurement */
+	ADCSRA |= (1<<ADSC);
+}
+
+ISR(ADC_vect) 
+{
+	if (controller_in_init) {
+		controller_measured_temp = ADCW;
+		controller_in_init = 0;
+	} else {
+		controller_measured_temp = (0.8 * controller_measured_temp)
+			                 + (0.2 * ADCW);
+	}
+
+	if (! controller_active)
+		return;
+
+	controller_num_iterations--;
+	if (controller_num_iterations)
+		return;
+
+	controller_num_iterations = 60;
+
+	if ((long)controller_measured_temp < controller_target_temp - 20) {
+		/* Cooling required */
+		bridge_on_cool();
+		return;
+	}
+
+	if ((long)controller_measured_temp > controller_target_temp + 20) {
+		/* Heating required */
+		bridge_on_heat();
+		return;
+	}
+
+	/* Temperature is roughly okay, turn bridge off until next
+	 * measurement. */
+	bridge_off();
+}
diff --git a/controller.h b/controller.h
new file mode 100644
index 0000000..0b65a73
--- /dev/null
+++ b/controller.h
@@ -0,0 +1,9 @@
+#ifndef CONTROLLER_H
+#define CONTROLLER_H
+
+void controller_init(void);
+int controller_set(long target);
+long controller_get(void);
+void controller_off(void);
+
+#endif
diff --git a/ferment.c b/ferment.c
deleted file mode 100644
index 1d282d2..0000000
--- a/ferment.c
+++ /dev/null
@@ -1,130 +0,0 @@
-//#define F_CPU 7372800UL
-#include <stdint.h>
-#include <string.h>
-#include <avr/io.h>
-#include <avr/interrupt.h>
-#include <avr/sleep.h>
-#include <avr/pgmspace.h>
-#include <avr/eeprom.h>
-#include <util/delay.h>
-
-#include "serial.h"
-#include "stdio.h"
-#include "pid.h"
-
-/* port D
- *
- *  4 1- (NMOS, inverted) 
- *  5 1+ (PMOS)
- *  6 2- (NMOS, inverted)
- *  7 2+ (PMOS)
- *
- */
-
-#define D_1_MINUS	(1 << 4)
-#define D_1_PLUS	(1 << 5)
-#define D_2_MINUS	(1 << 6)
-#define D_2_PLUS	(1 << 7)
-
-const int target_temp = 30;
-volatile uint16_t adc_res;
-volatile uint8_t adc_new;
-
-struct PID_DATA pid_data;
-
-/* Turns the H-bridge off, putting the output
- * into high impedance mode. */
-static void bridge_off(void)
-{
-	PORTD |= D_1_MINUS | D_2_MINUS;
-	PORTD &= ~(D_1_PLUS | D_2_PLUS);
-}
-
-/* Turns the H-bridge on, setting 1+ 2- */
-static void bridge_on_heat(void)
-{
-	bridge_off();
-	_delay_ms(100);
-	PORTD |= D_1_PLUS;
-	PORTD &= ~D_2_MINUS;
-}
-
-/* Turns the H-bridge on, setting 1- 2+ */
-static void bridge_on_cool(void)
-{
-	bridge_off();
-	_delay_ms(100);
-	PORTD |= D_2_PLUS;
-	PORTD &= ~D_1_MINUS;
-}
-
-/* Initializes the output port needed for the H-bridge */
-static void bridge_init(void)
-{
-	bridge_off();
-	DDRD |= D_1_PLUS | D_1_MINUS | D_2_PLUS | D_2_MINUS;
-}
-
-/* initializes ADC */
-static void adc_init(void)
-{
-	adc_new = 0;
-	ADMUX = (1 << REFS1) | (1 << REFS0);
-	/* select channel x (0 for now) */
-	ADMUX |= 0x0;
-	ADCSRA = (1 << ADEN) | (1 << ADIE) | (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);
-}
-
-/* reads ADC */
-static void start_temp_conv(void) 
-{
-	ADCSRA |= (1<<ADSC);
-}
-
-/* ADC completion interrupt */
-ISR(ADC_vect) 
-{
-	adc_res = ADCW;
-	adc_new = 1;
-}
-
-/* ADC results to temperature conversion routine */
-int adc_to_centigrade(uint16_t adc_val) {
-	return 0;
-}
-
-/* Initializes TIMER1 */
-static void timer_init(void)
-{
-	TCCR1B = (1 << WGM12) | (1 << CS12) | (1 << CS10);
-	OCR1A = 7200;
-	TIMSK|=(1<<OCIE1A);
-}
-
-ISR(TIMER1_COMPA_vect)
-{
-	serial_send("*\r\n", 3, 1);
-	start_temp_conv();
-}
-
-int main(void)
-{
-	char params[12];
-
-	serial_init();
-	adc_init();
-	timer_init();
-	bridge_init();
-
-	sei();
-
-	bridge_on_cool();
-	while (1) {
-		if (adc_new) {
-			sprintf(params, "%u\r\n", adc_res);
-			serial_send(params, strlen(params), 1);
-			adc_new = 0;
-		}
-		_delay_ms(100);
-	}
-}
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..a78e585
--- /dev/null
+++ b/main.c
@@ -0,0 +1,14 @@
+#include <avr/interrupt.h>
+
+#include "serial.h"
+#include "controller.h"
+
+int main(void)
+{
+	serial_init();
+	serial_toggle_verbose();
+	controller_init();
+
+	sei();
+	for (;;) ;
+}