Added board hardware driver support for the Adafruit U4 breakout board.

Fixed calculation of timer register reload values derived from F_CPU; must subtract one from the division result for the compare value to be correct.

Change AVRISP-MKII rescue clock speed to 4MHz to ensure that a 125KHz ISP speed works regardless of the target's fuses (i.e. DIV8 set).

5 files changed, 8 insertions, 8 deletions

diff --git a/Projects/AVRISP-MKII/AVRISP-MKII.txt b/Projects/AVRISP-MKII/AVRISP-MKII.txt
index 534af5639..d569e7e3e 100644
--- a/Projects/AVRISP-MKII/AVRISP-MKII.txt
+++ b/Projects/AVRISP-MKII/AVRISP-MKII.txt
@@ -105,9 +105,9 @@
  *   </tr>
  *  </table>
  *
- *  In addition, the AVR's OCR1A pin will generate a .5MHz clock, to act as an external rescue device clock
- *  if the fuses have been mis-set. To use the recovery clock, connect the OCR1A pin of the USB AVR to the target
- *  AVR's XTAL1 pin, and set the ISP programming speed to 125KHz (note: other ISP speeds will not work correctly).
+ *  In addition, the AVR's OCR1A pin will generate a 4MHz clock, to act as an external rescue device clock if the
+ *  fuses have been mis-set. To use the recovery clock, connect the OCR1A pin of the USB AVR to the target AVR's
+ *  XTAL1 pin, and set the ISP programming speed to 125KHz (note: other ISP speeds will not work correctly).
  *
  *  <b><sup>1</sup></b> <i>Optional, see \ref SSec_Options section - for USB AVRs with ADC modules only</i> \n
  *  <b><sup>2</sup></b> <i>See AUX line related tokens in the \ref SSec_Options section</i>
diff --git a/Projects/AVRISP-MKII/Lib/ISP/ISPTarget.c b/Projects/AVRISP-MKII/Lib/ISP/ISPTarget.c
index fe2f50d07..f4e9e3d3a 100644
--- a/Projects/AVRISP-MKII/Lib/ISP/ISPTarget.c
+++ b/Projects/AVRISP-MKII/Lib/ISP/ISPTarget.c
@@ -196,10 +196,10 @@ void ISPTarget_ConfigureRescueClock(void)
 	DDRB |= (1 << 5);
 	#endif
 
-	/* Start Timer 1 to generate a .5MHz clock on the OCR1A pin */
+	/* Start Timer 1 to generate a 4MHz clock on the OCR1A pin */
 	TIMSK1 = 0;
 	TCNT1  = 0;
-	OCR1A  = (F_CPU / 2 / 500000UL);
+	OCR1A  = ((F_CPU / 2 / 4000000UL) - 1);
 	TCCR1A = (1 << COM1A0);
 	TCCR1B = ((1 << WGM12) | (1 << CS10));
 }
diff --git a/Projects/AVRISP-MKII/Lib/V2Protocol.c b/Projects/AVRISP-MKII/Lib/V2Protocol.c
index e2c658673..618dedb43 100644
--- a/Projects/AVRISP-MKII/Lib/V2Protocol.c
+++ b/Projects/AVRISP-MKII/Lib/V2Protocol.c
@@ -61,7 +61,7 @@ void V2Protocol_Init(void)
 	#endif
 
 	/* Timeout timer initialization (10ms period) */
-	OCR0A  = ((F_CPU / 1024) / 100);
+	OCR0A  = (((F_CPU / 1024) / 100) - 1);
 	TCCR0A = (1 << WGM01);
 	TIMSK0 = (1 << OCIE0A);
 
diff --git a/Projects/TempDataLogger/TempDataLogger.c b/Projects/TempDataLogger/TempDataLogger.c
index c572a3870..c3cfd65f9 100644
--- a/Projects/TempDataLogger/TempDataLogger.c
+++ b/Projects/TempDataLogger/TempDataLogger.c
@@ -208,7 +208,7 @@ void SetupHardware(void)
 	TWI_Init();
 
 	/* 500ms logging interval timer configuration */
-	OCR1A   = ((F_CPU / 1024) / 2);
+	OCR1A   = (((F_CPU / 1024) / 2) - 1);
 	TCCR1B  = (1 << WGM12) | (1 << CS12) | (1 << CS10);
 	TIMSK1  = (1 << OCIE1A);
 
diff --git a/Projects/Webserver/Lib/uip/clock.c b/Projects/Webserver/Lib/uip/clock.c
index 86322966e..0906e6125 100644
--- a/Projects/Webserver/Lib/uip/clock.c
+++ b/Projects/Webserver/Lib/uip/clock.c
@@ -19,7 +19,7 @@ ISR(TIMER1_COMPA_vect)
 //Initialise the clock
 void clock_init()
 {
-	OCR1A  = ((F_CPU / 1024) / 100);
+	OCR1A  = (((F_CPU / 1024) / 100) - 1);
 	TCCR1B = ((1 << WGM12) | (1 << CS12) | (1 << CS10));
 	TIMSK1 = (1 << OCIE1A);
 }