From e0cd617537512cf3da20e99133b2bc6219067020 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Sat, 2 Aug 2014 23:50:05 -0700
Subject: [PATCH] add functionnality: memory is erased when holding button for
 5s

---
 pic/MDR/MDR.c | 39 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/pic/MDR/MDR.c b/pic/MDR/MDR.c
index 3f3898b..0b648e4 100644
--- a/pic/MDR/MDR.c
+++ b/pic/MDR/MDR.c
@@ -51,6 +51,7 @@ static uint8_t switches; /* save the last switch state */
 #define START 208 /* starting timer 0 value to wait up to 12ms in start_timer*/
 static uint8_t code[3] = {0xf1, 0x11, 0x11}; /* the received code (24 bits) */
 static uint8_t new = 0; /* has a new code been detected (clear using button) */
+static uint8_t hold = 0; /* how long has the button been held, in 250ms steps */
 
 /* configuration bits */
 uint16_t __at(_CONFIG1) __CONFIG1 = _FCMEN_ON & /* enable fail-safe clock monitor */
@@ -80,7 +81,7 @@ void init (void) {
 	LATA &= ~(RELAY1|RELAY2); /* switch relays off */
 	TRISB |= SWITCH1|SWITCH2; /* switches are inputs (with external pull-ups) */
 	TRISB &= ~(LED); /* LED is an output (used a sink) */
-	led_off(); /* starting state */
+	LATB |= LED; /* switch LED off */
 
 	/* configure switches input */
 	IOCIE = 1; /* enable interrupt on individual GPIO (typo in the lib) */
@@ -100,7 +101,7 @@ void init (void) {
 	TMR0IF = 0; /* clear timer 0 interrupt */
 
 	/* use timer 2 to measure pulse durations (max 16.384ms) */
-	TMR2ON = 1; /* stop timer 2 */
+	TMR2ON = 0; /* stop timer 2 */
 	T2CKPS0 = 1; /* use prescaler of 64 */
 	T2CKPS1 = 1; /* use prescaler of 64 */
 	T2OUTPS0 = 0; /* use postscale of 1 */
@@ -111,7 +112,19 @@ void init (void) {
 	TMR2IE = 1; /* enable timer 2 interrupt */
 	TMR2IF = 0; /* clear timer 2 interrupt */
 
-	/* the MDR originally uses a PIC16C54A
+	/* use timer 4 to measure button hold (250ms per interrupt) */
+	TMR4ON = 0; /* stop timer 4 */
+	T4CKPS0 = 1; /* use prescaler of 64 */
+	T4CKPS1 = 1; /* use prescaler of 64 */
+	T4OUTPS0 = 1; /* use postscale of 16 */
+	T4OUTPS1 = 1; /* use postscale of 16 */
+	T4OUTPS2 = 1; /* use postscale of 16 */
+	T4OUTPS3 = 1; /* use postscale of 16 */
+	PR4 = 244; /* set interrupt on overflow on this value to get 250ms */
+	TMR4IE = 1; /* enable timer 4 interrupt */
+	TMR4IF = 0; /* clear timer 4 interrupt */
+
+	/* the MDR originally uses a PIC16C54A (PDIP for MDR/MDR2, SOIC for MDR-U)
 	 * this does does not provide hardware I2C function
 	 * they implement I2C in software (it's even a bit buggy)
 	 * it even does not used open collectors (with pull-ups), but drives the signals
@@ -317,8 +330,11 @@ static void interrupt(void) __interrupt 0
 				if (PORTB&SWITCH1) { /* switch 1 released */
 					led_off(); /* reset LED */
 					new = 0; /* clear new code status */
+					TMR4ON = 0; /* stop counting how long the button is held */
 				} else { /* switch 1 pressed */
 					led_on(); /* test LED */
+					hold = 0; /* reset counter how long the button is held */
+					TMR4ON = 1; /* start counting how long the button is held */
 				}
 			}
 			if (switches&SWITCH2) { /* switch 2 changed */
@@ -338,6 +354,23 @@ static void interrupt(void) __interrupt 0
 		TMR2 = 0xff; /* set timer 2 count to maximum */
 		TMR2IF = 0; /* clear timer 2 interrupt */
 	}
+	if (TMR4IF) { /* timer 4 overflow, 250ms passed during button press */
+		hold++; /* increment 250ms counter */
+		/* toggle LED */
+		if (hold%2) {
+			led_off();
+		} else {
+			led_on();
+		}
+		/* pressed for 5s, clear memory */
+		if (hold==20) {
+			led_on();
+			clear_memory();
+			led_off();
+			TMR4ON = 0;
+		}
+		TMR4IF = 0; /* clear timer 4 interrupt */
+	}
 }
 
 void main (void)