From: Vladimir Garistov <vl_garistov@gmail.com>
Date: Fri, 5 Nov 2021 23:44:56 +0000 (+0200)
Subject: Added an example for modyfying a timer's frequency while it's running
X-Git-Url: https://kolegite.com/gitweb/?a=commitdiff_plain;h=3dcbe842e64c32674efa8deb1104c9a816b24e36;p=vmks.git

Added an example for modyfying a timer's frequency while it's running
---

diff --git a/Examples/Big_LED_strip/Big_LED_strip.ino b/Examples/Big_LED_strip/Big_LED_strip.ino
index 2a84342..60ee8ca 100644
--- a/Examples/Big_LED_strip/Big_LED_strip.ino
+++ b/Examples/Big_LED_strip/Big_LED_strip.ino
@@ -16,7 +16,7 @@
 	we must do so directly without allocating a working buffer.
 	Uncomment this to indicate that display_rgb_direct() must be used.
 */
-#define NEOPIXEL_ATE_MY_RAM
+//#define NEOPIXEL_ATE_MY_RAM
 //#define STM32
 
 #ifdef STM32
@@ -92,7 +92,7 @@ void setup()
 
 void loop()
 {
-	#ifndef NEOPIXEL_ATE_MY_RAM
+	#ifdef NEOPIXEL_ATE_MY_RAM
 	uint8_t frame_buffer[ROWS][COLS][3] = {{{0}}};
 
 	render_image(frame_buffer, big_image_data);
diff --git a/Examples/Timer_DIP_switch_frequency/Timer_DIP_switch_frequency.ino b/Examples/Timer_DIP_switch_frequency/Timer_DIP_switch_frequency.ino
new file mode 100644
index 0000000..4f1e4b7
--- /dev/null
+++ b/Examples/Timer_DIP_switch_frequency/Timer_DIP_switch_frequency.ino
@@ -0,0 +1,73 @@
+#define DIP_SW_0	8
+#define DIP_SW_1	9
+#define DIP_SW_2	10
+#define DIP_SW_3	11
+
+#define BUTTON		2
+#define LED			13
+
+void button_ISR(void);
+
+volatile bool led_flag = false;
+
+void setup()
+{
+  	pinMode(DIP_SW_0, INPUT_PULLUP);
+  	pinMode(DIP_SW_1, INPUT_PULLUP);
+  	pinMode(DIP_SW_2, INPUT_PULLUP);
+  	pinMode(DIP_SW_3, INPUT_PULLUP);
+  	pinMode(BUTTON, INPUT_PULLUP);
+  	pinMode(LED, OUTPUT);
+  	digitalWrite(LED, LOW);
+
+  	attachInterrupt(digitalPinToInterrupt(BUTTON), button_ISR, FALLING);
+
+  	// Disable interrupts during timer configuration
+  	cli();
+
+  	// Zero the control and counter registers
+  	TCCR1A = TCCR1B = TIMSK1 = 0;
+  	TCNT1 = 0;
+
+  	// Select mode 15 (Fast PWM, TOP = OCR1A)
+  	TCCR1A |= (1 << WGM10);
+  	TCCR1A |= (1 << WGM11);
+  	TCCR1B |= (1 << WGM12);
+  	TCCR1B |= (1 << WGM13);
+
+  	// Set max counter value (frequency)
+  	OCR1A = 7811;
+
+  	// Enable timer overflow interrupt
+  	TIMSK1 |= (1 << TOIE1);
+
+  	// Set prescaler to 1024
+  	TCCR1B |= (1 << CS10) | (1 << CS12);
+
+  	// Enable interrupts
+  	sei();
+
+  	Serial.begin(9600);
+}
+
+void loop()
+{
+  Serial.println(OCR1A);
+  delay(1000);
+}
+
+ISR(TIMER1_OVF_vect)
+{
+  	digitalWrite(LED, led_flag);
+  	led_flag = !led_flag;
+}
+
+void button_ISR(void)
+{
+  	uint8_t f = ~PINB & 0x0F;
+
+  	if (f)
+    {
+      	OCR1A = 16000000 / (1024 * f) - 1;
+    }
+}
diff --git a/Examples/Timer_DIP_switch_frequency/Timer_DIP_switch_frequency.png b/Examples/Timer_DIP_switch_frequency/Timer_DIP_switch_frequency.png
new file mode 100644
index 0000000..31a4373
Binary files /dev/null and b/Examples/Timer_DIP_switch_frequency/Timer_DIP_switch_frequency.png differ
diff --git a/Examples/Timer_DIP_switch_frequency/tinkercad_link.txt b/Examples/Timer_DIP_switch_frequency/tinkercad_link.txt
new file mode 100644
index 0000000..0095544
--- /dev/null
+++ b/Examples/Timer_DIP_switch_frequency/tinkercad_link.txt
@@ -0,0 +1 @@
+ https://www.tinkercad.com/things/2g5g32R3Fb7