Adding cutoff (ESTOP) support

firmware/src/Motherboard/EepromMap.hh

@@ -49,6 +49,14 @@ const static uint16_t MACHINE_NAME				= 0x0020;
 /// Default locations for the axis: 5 x 32 bit = 20 bytes
 const static uint16_t AXIS_HOME_POSITIONS		= 0x0060;
 
+// Estop configuration byte: 1 byte.
+const static uint16_t ESTOP_CONFIGURATION = 0x0074;
+
+enum {
+	ESTOP_CONF_NONE = 0x0,
+	ESTOP_CONF_ACTIVE_HIGH = 0x1,
+	ESTOP_CONF_ACTIVE_LOW = 0x2
+};
 
 /// Reset all data in the EEPROM to a default.
 void setDefaults();

firmware/src/Motherboard/Errors.hh

@@ -29,7 +29,7 @@
 #define ERR_HOST_PACKET_TIMEOUT         4
 #define ERR_HOST_PACKET_MISC            5
 #define ERR_WDT_TIMEOUT                 6
-
+#define ERR_ESTOP			7
 #define ERR_HOST_TRUNCATED_CMD          8
 
 #endif /* ERRORS_HH_ */

firmware/src/Motherboard/Main.cc

@@ -28,6 +28,7 @@
 #include "SDCard.hh"
 #include "Eeprom.hh"
 #include "EepromMap.hh"
+#include "Errors.hh"
 
 void reset(bool hard_reset) {
 	ATOMIC_BLOCK(ATOMIC_FORCEON) {
@@ -37,6 +38,16 @@ void reset(bool hard_reset) {
 		command::reset();
 		eeprom::init();
 		board.reset();
+#if HAS_ESTOP
+	const uint8_t estop_conf = eeprom::getEeprom8(eeprom::ESTOP_CONFIGURATION, 0);
+	if (estop_conf == eeprom::ESTOP_CONF_ACTIVE_HIGH) {
+		ESTOP_ENABLE_RISING_INT;
+	} else if (estop_conf == eeprom::ESTOP_CONF_ACTIVE_LOW) {
+		ESTOP_ENABLE_FALLING_INT;
+	}
+#endif
+
+
 		sei();
 		// If we've just come from a hard reset, wait for 2.5 seconds before
 		// trying to ping an extruder.  This gives the extruder time to boot
@@ -72,3 +83,16 @@ int main() {
 	}
 	return 0;
 }
+
+ISR(ESTOP_vect, ISR_NOBLOCK) {
+	// Emergency stop triggered; reset everything and kill the interface to RepG
+	INTERFACE_BAR_PIN.setValue(true);
+	INTERFACE_BAR_PIN.setDirection(true);
+	tool::reset();
+	steppers::abort();
+	command::reset();
+	UART::getHostUART().enable(false);
+	Motherboard::getBoard().indicateError(ERR_ESTOP);
+
+}
+

firmware/src/Motherboard/boards/mb24/Configuration.hh

@@ -73,6 +73,10 @@
 #define HAS_ESTOP               1
 // The pin connected to the emergency stop
 #define ESTOP_PIN               Pin(PortE,4)
+// Macros for enabling interrupts on the the pin. In this case, INT4.
+#define ESTOP_ENABLE_RISING_INT { EICRB = 0x03; EIMSK |= 0x10; }
+#define ESTOP_ENABLE_FALLING_INT { EICRB = 0x02; EIMSK |= 0x10; }
+#define ESTOP_vect INT4_vect
 
 
 // --- Axis configuration ---

firmware/src/Motherboard/boards/mb24/Motherboard.cc

@@ -132,6 +132,12 @@ void Motherboard::reset() {
 	// Configure the debug pin.
 	DEBUG_PIN.setDirection(true);
 
+#if HAS_ESTOP
+	// Configure the estop pin direction.
+	ESTOP_PIN.setDirection(false);
+#endif
+
+
 	// Check if the interface board is attached
         hasInterfaceBoard = interface::isConnected();