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-rw-r--r--examples/vga-scope.cpp212
1 files changed, 78 insertions, 134 deletions
diff --git a/examples/vga-scope.cpp b/examples/vga-scope.cpp
index 9c6dca5..0265f9c 100644
--- a/examples/vga-scope.cpp
+++ b/examples/vga-scope.cpp
@@ -1,90 +1,34 @@
-/*
- VGA Oscilloscope demo.
-
- Connect a microphone or something like it to ANALOG_PIN (0V -- 3.3V
- only; 0.2V -- 3.1V will probably look nicer); an attached VGA
- monitor will display the signal roughly in real-time.
-
- The thick blue line corresponds roughly to 0V.
-
- This is a fairy crude hack, but it's fun to watch/toy around with.
-
- SerialUSB and SysTick are disabled to get rid of the most frequently
- occurring interrupts (which mess with timing). This means that you
- have to use perpetual bootloader mode or the reset button to flash
- new programs.
-
- How to wire this to a VGA port:
- D6 via ~200ohms to VGA Red (1)
- D7 via ~200ohms to VGA Green (2)
- D8 via ~200ohms to VGA Blue (3)
- D11 to VGA VSync (14) (swapped?)
- D12 to VGA HSync (13) (swapped?)
- GND to VGA Ground (5)
- GND to VGA Sync Ground (10)
-
- See also:
- - http://pinouts.ru/Video/VGA15_pinout.shtml
- - http://www.epanorama.net/documents/pc/vga_timing.html
-
- This code is released into the public domain.
- */
+// Low-level, non-wirish demonstration of VGA
+//
+// Connect a microphone or something less to ANALOG_PIN
#include "wirish.h"
-#include "systick.h"
-
-// FIXME generalize for Native and Mini
-#define LED_PIN BOARD_LED_PIN
+#define LED_PIN 13
#define ANALOG_PIN 18
-
-// Pinouts -- you also must change the GPIO macros below if you change
-// these
-#define VGA_R 6 // STM32: A8
-#define VGA_G 7 // STM32: A9
-#define VGA_B 8 // STM32: A10
-#define VGA_V 11 // STM32: A6
-#define VGA_H 12 // STM32: A7
-
-// These low level (and STM32 specific) macros make GPIO writes much
-// faster
-#define ABSRR ((volatile uint32*)0x40010810)
-#define ABRR ((volatile uint32*)0x40010814)
-
-#define RBIT 8 // (see pinouts)
-#define GBIT 9
-#define BBIT 10
-
-#define VGA_R_HIGH *ABSRR = BIT(RBIT)
-#define VGA_R_LOW *ABRR = BIT(RBIT)
-#define VGA_G_HIGH *ABSRR = BIT(GBIT)
-#define VGA_G_LOW *ABRR = BIT(GBIT)
-#define VGA_B_HIGH *ABSRR = BIT(BBIT)
-#define VGA_B_LOW *ABRR = BIT(BBIT)
-
-#define COLOR_WHITE (BIT(RBIT) | BIT(GBIT) | BIT(BBIT))
-#define COLOR_BLACK 0
-#define COLOR_RED BIT(RBIT)
-#define COLOR_GREEN BIT(GBIT)
-#define COLOR_BLUE BIT(BBIT)
-
-#define BORDER_COLOR COLOR_BLUE
-
-// set has priority, so clear every bit and set some given bits:
-#define VGA_COLOR(c) (*ABSRR = c | \
- BIT(RBIT+16) | BIT(GBIT+16) | BIT(BBIT+16))
-
-#define VGA_V_HIGH *ABSRR = BIT(6)
-#define VGA_V_LOW *ABRR = BIT(6)
-#define VGA_H_HIGH *ABSRR = BIT(7)
-#define VGA_H_LOW *ABRR = BIT(7)
+#define VGA_R 5 // B6
+#define VGA_G 6 // A8
+#define VGA_B 7 // A9
+#define VGA_V 11 // A6
+#define VGA_H 12 // A7
+#define VGA_R_HIGH (GPIOB_BASE)->BSRR = BIT(6)
+#define VGA_R_LOW (GPIOB_BASE)->BRR = BIT(6)
+#define VGA_G_HIGH (GPIOA_BASE)->BSRR = BIT(8)
+#define VGA_G_LOW (GPIOA_BASE)->BRR = BIT(8)
+#define VGA_B_HIGH (GPIOA_BASE)->BSRR = BIT(9)
+#define VGA_B_LOW (GPIOA_BASE)->BRR = BIT(9)
+#define VGA_V_HIGH (GPIOA_BASE)->BSRR = BIT(6)
+#define VGA_V_LOW (GPIOA_BASE)->BRR = BIT(6)
+#define VGA_H_HIGH (GPIOA_BASE)->BSRR = BIT(7)
+#define VGA_H_LOW (GPIOA_BASE)->BRR = BIT(7)
void isr_porch(void);
void isr_start(void);
void isr_stop(void);
void isr_update(void);
-void setup() {
+void setup()
+{
pinMode(LED_PIN, OUTPUT);
pinMode(ANALOG_PIN, INPUT_ANALOG);
digitalWrite(LED_PIN, 1);
@@ -94,104 +38,104 @@ void setup() {
pinMode(VGA_V, OUTPUT);
pinMode(VGA_H, OUTPUT);
- // Send a message out USART2
+ /* Send a message out USART2 */
Serial2.begin(9600);
- Serial2.println("Time to kill the radio star...");
+ Serial2.println("Video time...");
// This gets rid of the majority of the interrupt artifacts;
- // there's still a glitch for low values of y, but let's not worry
- // about that. (Probably due to the hackish way vsync is done).
+ // a SysTick.end() is required as well
SerialUSB.end();
- systick_disable();
-
+
digitalWrite(VGA_R, 0);
digitalWrite(VGA_G, 0);
digitalWrite(VGA_B, 0);
- digitalWrite(VGA_H, 1);
- digitalWrite(VGA_V, 1);
-
- timer_pause(TIMER4);
- timer_set_prescaler(TIMER4, 0);
- timer_set_mode(TIMER4, 1, TIMER_OUTPUTCOMPARE);
- timer_set_mode(TIMER4, 2, TIMER_OUTPUTCOMPARE);
- timer_set_mode(TIMER4, 3, TIMER_OUTPUTCOMPARE);
- timer_set_mode(TIMER4, 4, TIMER_OUTPUTCOMPARE);
- timer_set_reload(TIMER4, 2287);
- timer_set_compare_value(TIMER4, 1, 200);
- timer_set_compare_value(TIMER4, 2, 250);
- timer_set_compare_value(TIMER4, 3, 2170); // 2219 max...
- timer_set_compare_value(TIMER4, 4, 1);
- timer_attach_interrupt(TIMER4, 1, isr_porch);
- timer_attach_interrupt(TIMER4, 2, isr_start);
- timer_attach_interrupt(TIMER4, 3, isr_stop);
- timer_attach_interrupt(TIMER4, 4, isr_update);
-
- timer_set_count(TIMER4, 0);
- timer_resume(TIMER4);
+ digitalWrite(VGA_H,1);
+ digitalWrite(VGA_V,1);
+
+ timer_set_prescaler(4,0);
+ timer_set_mode(4, 1, TIMER_OUTPUTCOMPARE);
+ timer_set_mode(4, 2, TIMER_OUTPUTCOMPARE);
+ timer_set_mode(4, 3, TIMER_OUTPUTCOMPARE);
+ timer_set_mode(4, 4, TIMER_OUTPUTCOMPARE);
+ timer_set_reload(4, 2287);
+ timer_set_compare_value(4,1,200);
+ timer_set_compare_value(4,2,300);
+ timer_set_compare_value(4,3,2170); // 2219 max...
+ timer_set_compare_value(4,4,1);
+ timer_attach_interrupt(4,1,isr_porch);
+ timer_attach_interrupt(4,2,isr_start);
+ timer_attach_interrupt(4,3,isr_stop);
+ timer_attach_interrupt(4,4,isr_update);
+
+ timer_set_count(4,0);
}
+int toggle = 0;
+uint16 x = 0;
uint16 y = 0;
uint16 val = 0;
-bool v_active = true;
-const uint16 x_max = 60; // empirically (and lazily) determined
+uint8 v_active = 1;
+GPIO_Port *portb = GPIOB_BASE;
void isr_porch(void) {
VGA_H_HIGH;
y++;
- val = map(analogRead(ANALOG_PIN), 0, 4095, 0, x_max);
- if(y >= 523) {
- y = 1;
- v_active = true;
+ if(y>=523) {
+ y=1;
+ v_active = 1;
return;
}
- if(y >= 492) {
+ if(y>=492) {
VGA_V_HIGH;
return;
}
- if(y >= 490) {
+ if(y>=490) {
VGA_V_LOW;
return;
}
- if(y >= 479) {
- v_active = false;
+ if(y>=479) { // 479
+ v_active = 0;
return;
}
}
void isr_start(void) {
- if (!v_active) {
- return;
- }
- VGA_COLOR(BORDER_COLOR);
- for (int x = 0; x < val; x++) {
- VGA_COLOR(COLOR_BLACK);
- }
- VGA_COLOR(COLOR_WHITE);
- VGA_COLOR(COLOR_BLACK);
-}
+ if(!v_active) { return; }
+ VGA_R_HIGH;
+ VGA_R_HIGH;
+ VGA_R_HIGH;
+ VGA_R_LOW;
+ //delayMicroseconds(2);
+ //gpio_write_bit(GPIOA_BASE, 8, 1); // VGA_G
+ for(x=0; x<(val>>6); x++) {
+ }
+ VGA_B_HIGH;
+ VGA_G_HIGH;
+ VGA_G_LOW;
+ VGA_B_LOW;
+ //VGA_R_HIGH;
+ //val = (val + analogRead(ANALOG_PIN))/2;
+ val = analogRead(ANALOG_PIN);
+}
void isr_stop(void) {
- if (!v_active) {
- return;
- }
- VGA_COLOR(COLOR_BLACK);
+ if(!v_active) { return; }
+ VGA_R_LOW;
+ VGA_G_LOW;
+ VGA_B_LOW;
}
-
void isr_update(void) {
VGA_H_LOW;
}
void loop() {
- toggleLED();
- delay(100);
+ //val = analogRead(ANALOG_PIN);
}
-__attribute__((constructor)) void premain() {
- init();
-}
int main(void) {
+ init();
setup();
while (1) {
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