// Original version from https://github.com/adafruit/Adafruit_NeoPixel // Modifications by dpgeorge to support auto-CPU-frequency detection // This is a mash-up of the Due show() code + insights from Michael Miller's // ESP8266 work for the NeoPixelBus library: github.com/Makuna/NeoPixelBus // Needs to be a separate .c file to enforce ICACHE_RAM_ATTR execution. #include "py/mpconfig.h" #if MICROPY_ESP8266_NEOPIXEL #include "c_types.h" #include "eagle_soc.h" #include "user_interface.h" #include "espneopixel.h" #include "esp_mphal.h" #define NEO_KHZ400 (1) void /*ICACHE_RAM_ATTR*/ esp_neopixel_write(uint8_t pin, uint8_t *pixels, uint32_t numBytes, bool is800KHz) { uint8_t *p, *end, pix, mask; uint32_t t, time0, time1, period, c, startTime, pinMask; pinMask = 1 << pin; p = pixels; end = p + numBytes; pix = *p++; mask = 0x80; startTime = 0; uint32_t fcpu = system_get_cpu_freq() * 1000000; #ifdef NEO_KHZ400 if(is800KHz) { #endif time0 = fcpu / 2857143; // 0.35us time1 = fcpu / 1250000; // 0.8us period = fcpu / 800000; // 1.25us per bit #ifdef NEO_KHZ400 } else { // 400 KHz bitstream time0 = fcpu / 2000000; // 0.5uS time1 = fcpu / 833333; // 1.2us period = fcpu / 400000; // 2.5us per bit } #endif uint32_t irq_state = mp_hal_quiet_timing_enter(); for(t = time0;; t = time0) { if(pix & mask) t = time1; // Bit high duration while(((c = mp_hal_ticks_cpu()) - startTime) < period); // Wait for bit start GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, pinMask); // Set high startTime = c; // Save start time while(((c = mp_hal_ticks_cpu()) - startTime) < t); // Wait high duration GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, pinMask); // Set low if(!(mask >>= 1)) { // Next bit/byte if(p >= end) break; pix = *p++; mask = 0x80; } } while((mp_hal_ticks_cpu() - startTime) < period); // Wait for last bit mp_hal_quiet_timing_exit(irq_state); } #endif // MICROPY_ESP8266_NEOPIXEL