111 lines
3.6 KiB
C
111 lines
3.6 KiB
C
#include "quantum.h"
|
|
#include "ws2812.h"
|
|
#include <ch.h>
|
|
#include <hal.h>
|
|
|
|
/* Adapted from https://github.com/bigjosh/SimpleNeoPixelDemo/ */
|
|
|
|
#ifndef NOP_FUDGE
|
|
# if defined(STM32F0XX) || defined(STM32F1XX) || defined(STM32F3XX) || defined(STM32F4XX) || defined(STM32L0XX)
|
|
# define NOP_FUDGE 0.4
|
|
# else
|
|
# error("NOP_FUDGE configuration required")
|
|
# define NOP_FUDGE 1 // this just pleases the compile so the above error is easier to spot
|
|
# endif
|
|
#endif
|
|
|
|
// Push Pull or Open Drain Configuration
|
|
// Default Push Pull
|
|
#ifndef WS2812_EXTERNAL_PULLUP
|
|
# define WS2812_OUTPUT_MODE PAL_MODE_OUTPUT_PUSHPULL
|
|
#else
|
|
# define WS2812_OUTPUT_MODE PAL_MODE_OUTPUT_OPENDRAIN
|
|
#endif
|
|
|
|
#define NUMBER_NOPS 6
|
|
#define CYCLES_PER_SEC (STM32_SYSCLK / NUMBER_NOPS * NOP_FUDGE)
|
|
#define NS_PER_SEC (1000000000L) // Note that this has to be SIGNED since we want to be able to check for negative values of derivatives
|
|
#define NS_PER_CYCLE (NS_PER_SEC / CYCLES_PER_SEC)
|
|
#define NS_TO_CYCLES(n) ((n) / NS_PER_CYCLE)
|
|
|
|
#define wait_ns(x) \
|
|
do { \
|
|
for (int i = 0; i < NS_TO_CYCLES(x); i++) { \
|
|
__asm__ volatile("nop\n\t" \
|
|
"nop\n\t" \
|
|
"nop\n\t" \
|
|
"nop\n\t" \
|
|
"nop\n\t" \
|
|
"nop\n\t"); \
|
|
} \
|
|
} while (0)
|
|
|
|
// These are the timing constraints taken mostly from the WS2812 datasheets
|
|
// These are chosen to be conservative and avoid problems rather than for maximum throughput
|
|
|
|
#define T1H 900 // Width of a 1 bit in ns
|
|
#define T1L (1250 - T1H) // Width of a 1 bit in ns
|
|
|
|
#define T0H 350 // Width of a 0 bit in ns
|
|
#define T0L (1250 - T0H) // Width of a 0 bit in ns
|
|
|
|
// The reset gap can be 6000 ns, but depending on the LED strip it may have to be increased
|
|
// to values like 600000 ns. If it is too small, the pixels will show nothing most of the time.
|
|
#define RES (1000 * WS2812_TRST_US) // Width of the low gap between bits to cause a frame to latch
|
|
|
|
void sendByte(uint8_t byte) {
|
|
// WS2812 protocol wants most significant bits first
|
|
for (unsigned char bit = 0; bit < 8; bit++) {
|
|
bool is_one = byte & (1 << (7 - bit));
|
|
// using something like wait_ns(is_one ? T1L : T0L) here throws off timings
|
|
if (is_one) {
|
|
// 1
|
|
writePinHigh(RGB_DI_PIN);
|
|
wait_ns(T1H);
|
|
writePinLow(RGB_DI_PIN);
|
|
wait_ns(T1L);
|
|
} else {
|
|
// 0
|
|
writePinHigh(RGB_DI_PIN);
|
|
wait_ns(T0H);
|
|
writePinLow(RGB_DI_PIN);
|
|
wait_ns(T0L);
|
|
}
|
|
}
|
|
}
|
|
|
|
void ws2812_init(void) { palSetLineMode(RGB_DI_PIN, WS2812_OUTPUT_MODE); }
|
|
|
|
// Setleds for standard RGB
|
|
void ws2812_setleds(LED_TYPE *ledarray, uint16_t leds) {
|
|
static bool s_init = false;
|
|
if (!s_init) {
|
|
ws2812_init();
|
|
s_init = true;
|
|
}
|
|
|
|
// this code is very time dependent, so we need to disable interrupts
|
|
chSysLock();
|
|
|
|
for (uint8_t i = 0; i < leds; i++) {
|
|
// WS2812 protocol dictates grb order
|
|
#if (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_GRB)
|
|
sendByte(ledarray[i].g);
|
|
sendByte(ledarray[i].r);
|
|
sendByte(ledarray[i].b);
|
|
#elif (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_RGB)
|
|
sendByte(ledarray[i].r);
|
|
sendByte(ledarray[i].g);
|
|
sendByte(ledarray[i].b);
|
|
#endif
|
|
|
|
#ifdef RGBW
|
|
sendByte(ledarray[i].w);
|
|
#endif
|
|
}
|
|
|
|
wait_ns(RES);
|
|
|
|
chSysUnlock();
|
|
}
|