esp8266: Add APA102 serial individually controllable LEDs support.
APA102 is a new "smart LED", similar to WS2812 aka "Neopixel".
diff --git a/esp8266/espapa102.c b/esp8266/espapa102.c
new file mode 100644
index 0000000..e5f3024
--- /dev/null
+++ b/esp8266/espapa102.c
@@ -0,0 +1,110 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Robert Foss, Daniel Busch
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include "c_types.h"
+#include "eagle_soc.h"
+#include "user_interface.h"
+#include "espapa102.h"
+
+#define NOP asm volatile(" nop \n\t")
+
+static inline void _esp_apa102_send_byte(uint32_t clockPinMask, uint32_t dataPinMask, uint8_t byte) {
+ for (uint32_t i = 0; i < 8; i++) {
+ if (byte & 0x80) {
+ // set data pin high
+ GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, dataPinMask);
+ } else {
+ // set data pin low
+ GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, dataPinMask);
+ }
+
+ // set clock pin high
+ GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, clockPinMask);
+ byte <<= 1;
+ NOP;
+ NOP;
+
+ // set clock pin low
+ GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, clockPinMask);
+ NOP;
+ NOP;
+ }
+}
+
+static inline void _esp_apa102_send_colors(uint32_t clockPinMask, uint32_t dataPinMask, uint8_t *pixels, uint32_t numBytes) {
+ for (uint32_t i = 0; i < numBytes / 4; i++) {
+ _esp_apa102_send_byte(clockPinMask, dataPinMask, pixels[i * 4 + 3] | 0xE0);
+ _esp_apa102_send_byte(clockPinMask, dataPinMask, pixels[i * 4 + 2]);
+ _esp_apa102_send_byte(clockPinMask, dataPinMask, pixels[i * 4 + 1]);
+ _esp_apa102_send_byte(clockPinMask, dataPinMask, pixels[i * 4]);
+ }
+}
+
+static inline void _esp_apa102_start_frame(uint32_t clockPinMask, uint32_t dataPinMask) {
+ for (uint32_t i = 0; i < 4; i++) {
+ _esp_apa102_send_byte(clockPinMask, dataPinMask, 0x00);
+ }
+}
+
+static inline void _esp_apa102_append_additionial_cycles(uint32_t clockPinMask, uint32_t dataPinMask, uint32_t numBytes) {
+ GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, dataPinMask);
+
+ // we need to write some more clock cycles, because each led
+ // delays the data by one edge after inverting the clock
+ for (uint32_t i = 0; i < numBytes / 8 + ((numBytes / 4) % 2); i++) {
+ GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, clockPinMask);
+ NOP;
+ NOP;
+
+ GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, clockPinMask);
+ NOP;
+ NOP;
+ }
+}
+
+static inline void _esp_apa102_end_frame(uint32_t clockPinMask, uint32_t dataPinMask) {
+ for (uint32_t i = 0; i < 4; i++) {
+ _esp_apa102_send_byte(clockPinMask, dataPinMask, 0xFF);
+ }
+}
+
+void esp_apa102_write(uint8_t clockPin, uint8_t dataPin, uint8_t *pixels, uint32_t numBytes) {
+ uint32_t clockPinMask, dataPinMask;
+
+ clockPinMask = 1 << clockPin;
+ dataPinMask = 1 << dataPin;
+
+ // start the frame
+ _esp_apa102_start_frame(clockPinMask, dataPinMask);
+
+ // write pixels
+ _esp_apa102_send_colors(clockPinMask, dataPinMask, pixels, numBytes);
+
+ // end the frame
+ _esp_apa102_append_additionial_cycles(clockPinMask, dataPinMask, numBytes);
+ _esp_apa102_end_frame(clockPinMask, dataPinMask);
+}