Review power supply timeout.

- Move the variable from dda.c to pinio.c.

- Reset the timeout on each power on, to guarantee a minimum PSU on time.

clock.c

@@ -25,14 +25,14 @@
 void clock_250ms() {
 	#ifndef	NO_AUTO_IDLE
 	if (temp_all_zero())	{
-		if (steptimeout > (30 * 4)) {
+		if (psu_timeout > (30 * 4)) {
 			power_off();
 		}
 		else {
 			uint8_t save_reg = SREG;
 			cli();
 			CLI_SEI_BUG_MEMORY_BARRIER();
-			steptimeout++;
+			psu_timeout++;
 			MEMORY_BARRIER();
 			SREG = save_reg;
 		}

dda.c

@@ -28,9 +28,6 @@
 #error STEPS_PER_MM_Y is gone, review your config.h and use STEPS_PER_M_Y
 #endif
 
-/// step timeout
-volatile uint8_t	steptimeout = 0;
-
 /*
 	position tracking
 */
@@ -275,7 +272,6 @@ void dda_create(DDA *dda, TARGET *target) {
 	}
 	else {
 		// get steppers ready to go
-		steptimeout = 0;
 		power_on();
 		stepper_enable();
 		x_enable();
@@ -483,7 +479,7 @@ void dda_start(DDA *dda) {
 	// called from interrupt context: keep it simple!
 	if ( ! dda->nullmove) {
 		// get ready to go
-		steptimeout = 0;
+		psu_timeout = 0;
 		if (dda->z_delta)
 			z_enable();
 
@@ -823,7 +819,7 @@ void dda_step(DDA *dda) {
 		z_disable();
 	}
 	else
-		steptimeout = 0;
+		psu_timeout = 0;
 
 	#ifdef ACCELERATION_RAMPING
 		// we don't hit maximum speed exactly with acceleration calculation, so limit it here

dda.h

@@ -221,10 +221,6 @@ typedef struct {
 	variables
 */
 
-/// steptimeout is set to zero when we step, and increases over time so we can turn the motors off when they've been idle for a while
-/// It is also used inside and outside of interrupts, which is why it has been made volatile
-extern volatile uint8_t steptimeout;
-
 /// startpoint holds the endpoint of the most recently created DDA, so we know where the next one created starts. could also be called last_endpoint
 extern TARGET startpoint;
 

gcode_process.c

@@ -704,7 +704,6 @@ void process_gcode_command() {
 				y_enable();
 				z_enable();
 				e_enable();
-				steptimeout = 0;
 				break;
 
 			case 191:

pinio.c

@@ -3,6 +3,9 @@
 
 static char ps_is_on = 0;
 
+/// step/psu timeout
+volatile uint8_t	psu_timeout = 0;
+
 void power_on() {
 
 	if (ps_is_on == 0) {
@@ -13,6 +16,8 @@ void power_on() {
 		#endif
 		ps_is_on = 1;
 	}
+
+	psu_timeout = 0;
 }
 
 void power_off() {

pinio.h

@@ -11,6 +11,13 @@
 Power
 */
 
+/// psu_timeout is set to zero when we step, and increases over time so we can
+/// turn the motors off when they've been idle for a while.
+/// A second function is to guarantee a minimum on time of the PSU.
+/// Timeout counting is done in clock.c.
+/// It is used inside and outside of interrupts, which is why it has been made volatile
+extern volatile uint8_t psu_timeout;
+
 void power_on(void);
 void power_off(void);