1 files changed, 134 insertions, 0 deletions
diff --git a/lock/bend.c b/lock/bend.c
new file mode 100644
index 0000000..0b1061d
--- /dev/null
+++ b/lock/bend.c
@@ -0,0 +1,134 @@
+/* Lock back, connected to the servo */
+
+#include <stdint.h>
+#include <string.h>
+
+#include <avr/interrupt.h>
+#include <avr/wdt.h>
+#include <util/delay.h>
+
+#include "nrfm.h"
+#include "uart.h"
+#include "util.h"
+
+#define PWM_MIN      500
+#define PWM_MID      1500
+#define PWM_MAX      2500
+#define PWM_TOP      20000
+
+#define SERVO_PIN    PB1
+#define LOCK_BTN     PD6
+#define UNLOCK_BTN   PD7
+
+#define RX_PIN       PD7
+#define RX_DDR       DDRD
+#define RX_PORT      PORTD
+#define RX_PCIE      PCIE2
+#define RX_PCINT     PCINT23
+#define RX_PCMSK     PCMSK2
+#define RX_PCINTVEC  PCINT2_vect
+
+static char tab[] = {
+	'0', '8', '3', '6', 'a', 'Z', '$', '4', 'v', 'R', '@',
+	'E', '1', 'o', '#', ')', '2', '5', 'q', ';', '.', 'I',
+	'c', '7', '9', '*', 'L', 'V', '&', 'k', 'K', '!', 'm',
+	'N', '(', 'O', 'Q', 'A', '>', 'T', 't', '?', 'S', 'h',
+	'w', '/', 'n', 'W', 'l', 'M', 'e', 'H', 'j', 'g', '[',
+	'P', 'f', ':', 'B', ']', 'Y', '^', 'F', '%', 'C', 'x'
+};
+
+static uint8_t syn = 0;
+static volatile uint8_t rxdr = 0;
+static uint16_t tablen = sizeof(tab) / sizeof(tab[0]);
+
+static inline void keygen(char *buf, uint8_t n)
+{
+	int i, imax;
+	uint8_t sreg;
+	uint16_t seed; 
+	
+	sreg = SREG;
+	cli();
+	seed = TCNT1; 
+	SREG = sreg;
+
+	for (i = 0, imax = n - 1; i < imax; i++, seed++)
+		buf[i] = tab[(seed % tablen)];
+	buf[imax] = '\0';
+}
+
+static inline void keydel(char *buf, uint8_t n)
+{
+	int i;
+
+	for (i = 0; i < n; i++)
+		buf[i] = 0;
+}
+
+static inline void servo_init(void)
+{
+	DDRB |= (1 << SERVO_PIN);
+
+	TCCR1A |= (1 << WGM11) | (1 << COM1A1);
+	TCCR1B |= (1 << WGM13) | (1 << CS11);
+	ICR1 = PWM_TOP;
+
+	DDRD &= ~((1 << LOCK_BTN) | (1 << UNLOCK_BTN));
+	PORTD |= (1 << LOCK_BTN) | (1 << UNLOCK_BTN);
+}
+
+int main(void)
+{
+	uint8_t n;
+	uint8_t rxaddr[ADDRLEN] = { 194, 178, 83 };
+	uint8_t txaddr[ADDRLEN] = { 194, 178, 82 };
+
+	char buf[WDLEN + 1], key[WDLEN + 1], msg[WDLEN + 1];
+
+	RX_DDR &= ~(1 << RX_PIN);
+	RX_PORT |= (1 << RX_PIN); 
+	PCICR |= (1 << RX_PCIE);
+	RX_PCMSK |= (1 << RX_PCINT);
+
+	uart_init();
+	servo_init();
+	radio_init(rxaddr);
+	radio_print_config();
+
+	sei();
+	radio_listen();
+
+	for (;;) {
+		if (rxdr) {
+			rxdr = 0;
+			n = radio_recv(buf, WDLEN);
+			buf[n] = '\0';	
+			if (!syn) {
+				xor(KEY, buf, msg, WDLEN);
+				if (strncmp(msg, SYN, WDLEN) == 0) {
+					keygen(key, WDLEN + 1);
+					xor(KEY, key, buf, WDLEN);
+					radio_sendto(txaddr, buf, WDLEN);
+					syn = 1;
+				}
+			} else {
+				syn = 0;
+				xor(key, buf, msg, WDLEN);
+				if (strncmp(msg, LOCK, WDLEN) == 0) {
+					// todo: lock
+				} else if (strncmp(msg, UNLOCK, WDLEN) == 0) {
+					// todo: unlock
+				}
+				keydel(buf, WDLEN);
+			}
+		} else {
+			// todo: sleep
+		}
+	}
+	return 0;
+}
+
+ISR(RX_PCINTVEC)
+{
+	rxdr = 1;
+}