From 02e76ec27b5737bce836a5460427b538076f01ef Mon Sep 17 00:00:00 2001 From: Marti Bolivar Date: Fri, 4 Mar 2011 20:25:26 -0500 Subject: Brought examples/ up to date; PIN_MAP bugfix for D24. --- examples/vga-scope.cpp | 212 +++++++++++++++++++++++++++++++------------------ 1 file changed, 134 insertions(+), 78 deletions(-) (limited to 'examples/vga-scope.cpp') diff --git a/examples/vga-scope.cpp b/examples/vga-scope.cpp index 0265f9c..9c6dca5 100644 --- a/examples/vga-scope.cpp +++ b/examples/vga-scope.cpp @@ -1,34 +1,90 @@ -// Low-level, non-wirish demonstration of VGA -// -// Connect a microphone or something less to ANALOG_PIN +/* + 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. + */ #include "wirish.h" +#include "systick.h" + +// FIXME generalize for Native and Mini -#define LED_PIN 13 +#define LED_PIN BOARD_LED_PIN #define ANALOG_PIN 18 -#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) + +// 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) 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); @@ -38,104 +94,104 @@ 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("Video time..."); + Serial2.println("Time to kill the radio star..."); // This gets rid of the majority of the interrupt artifacts; - // a SysTick.end() is required as well + // 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). 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_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); + 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); } -int toggle = 0; -uint16 x = 0; uint16 y = 0; uint16 val = 0; -uint8 v_active = 1; -GPIO_Port *portb = GPIOB_BASE; +bool v_active = true; +const uint16 x_max = 60; // empirically (and lazily) determined void isr_porch(void) { VGA_H_HIGH; y++; - if(y>=523) { - y=1; - v_active = 1; + val = map(analogRead(ANALOG_PIN), 0, 4095, 0, x_max); + if(y >= 523) { + y = 1; + v_active = true; return; } - if(y>=492) { + if(y >= 492) { VGA_V_HIGH; return; } - if(y>=490) { + if(y >= 490) { VGA_V_LOW; return; } - if(y>=479) { // 479 - v_active = 0; + if(y >= 479) { + v_active = false; return; } } void isr_start(void) { - 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); - + 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); } + void isr_stop(void) { - if(!v_active) { return; } - VGA_R_LOW; - VGA_G_LOW; - VGA_B_LOW; + if (!v_active) { + return; + } + VGA_COLOR(COLOR_BLACK); } + void isr_update(void) { VGA_H_LOW; } void loop() { - //val = analogRead(ANALOG_PIN); + toggleLED(); + delay(100); } +__attribute__((constructor)) void premain() { + init(); +} int main(void) { - init(); setup(); while (1) { -- cgit v1.2.3