esp32: Add support for WS2812 and APA106 RGB LEDs.

tyggerjai · dpgeorge · commit f3913bfdfb3b · 2017-03-14T13:32:50.000+11:00
diff --git a/esp32/Makefile b/esp32/Makefile
@@ -127,6 +127,7 @@ SRC_C = \
 	modnetwork.c \
 	modsocket.c \
 	modesp.c \
+	espneopixel.c \
 	$(SRC_MOD)
 
 STM_SRC_C = $(addprefix stmhal/,\
diff --git a/esp32/espneopixel.c b/esp32/espneopixel.c
@@ -0,0 +1,53 @@
+// 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"
+#include "py/mphal.h"
+#include "modesp.h"
+
+void IRAM_ATTR esp_neopixel_write(uint8_t pin, uint8_t *pixels, uint32_t numBytes, uint8_t timing) {
+    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 = ets_get_cpu_frequency() * 1000000;
+
+    if (timing == 1) {
+        // 800 KHz
+        time0 = (fcpu * 0.35) / 1000000; // 0.35us
+        time1 = (fcpu * 0.8) / 1000000; // 0.8us
+        period = (fcpu * 1.25) / 1000000; // 1.25us per bit
+    } else {
+        // 400 KHz
+        time0 = (fcpu * 0.5) / 1000000; // 0.35us
+        time1 = (fcpu * 1.2) / 1000000; // 0.8us
+        period = (fcpu * 2.5) / 1000000; // 1.25us per bit
+    }
+
+    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_REG, 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_REG, 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);
+}
diff --git a/esp32/modesp.c b/esp32/modesp.c
@@ -33,7 +33,9 @@
 
 #include "py/runtime.h"
 #include "py/mperrno.h"
+#include "py/mphal.h"
 #include "drivers/dht/dht.h"
+#include "modesp.h"
 
 STATIC mp_obj_t esp_flash_read(mp_obj_t offset_in, mp_obj_t buf_in) {
     mp_int_t offset = mp_obj_get_int(offset_in);
@@ -79,6 +81,15 @@ STATIC mp_obj_t esp_flash_user_start(void) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_0(esp_flash_user_start_obj, esp_flash_user_start);
 
+STATIC mp_obj_t esp_neopixel_write_(mp_obj_t pin, mp_obj_t buf, mp_obj_t timing) {
+    mp_buffer_info_t bufinfo;
+    mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_READ);
+    esp_neopixel_write(mp_hal_get_pin_obj(pin),
+        (uint8_t*)bufinfo.buf, bufinfo.len, mp_obj_get_int(timing));
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_3(esp_neopixel_write_obj, esp_neopixel_write_);
+
 STATIC const mp_rom_map_elem_t esp_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_esp) },
 
@@ -88,6 +99,7 @@ STATIC const mp_rom_map_elem_t esp_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_flash_size), MP_ROM_PTR(&esp_flash_size_obj) },
     { MP_ROM_QSTR(MP_QSTR_flash_user_start), MP_ROM_PTR(&esp_flash_user_start_obj) },
 
+    { MP_ROM_QSTR(MP_QSTR_neopixel_write), MP_ROM_PTR(&esp_neopixel_write_obj) },
     { MP_ROM_QSTR(MP_QSTR_dht_readinto), MP_ROM_PTR(&dht_readinto_obj) },
 };
 
@@ -97,3 +109,4 @@ const mp_obj_module_t esp_module = {
     .base = { &mp_type_module },
     .globals = (mp_obj_dict_t*)&esp_module_globals,
 };
+
diff --git a/esp32/modesp.h b/esp32/modesp.h
@@ -0,0 +1 @@
+void esp_neopixel_write(uint8_t pin, uint8_t *pixels, uint32_t numBytes, uint8_t timing);
diff --git a/esp32/modules/apa106.py b/esp32/modules/apa106.py
@@ -0,0 +1,8 @@
+# APA106driver for MicroPython on ESP32
+# MIT license; Copyright (c) 2016 Damien P. George
+
+from neopixel import NeoPixel
+
+
+class APA106(NeoPixel):
+    ORDER = (0, 1, 2, 3)
diff --git a/esp32/modules/neopixel.py b/esp32/modules/neopixel.py
@@ -0,0 +1,33 @@
+# NeoPixel driver for MicroPython on ESP32
+# MIT license; Copyright (c) 2016 Damien P. George
+
+from esp import neopixel_write
+
+
+class NeoPixel:
+    ORDER = (1, 0, 2, 3)
+    
+    def __init__(self, pin, n, bpp=3, timing=0):
+        self.pin = pin
+        self.n = n
+        self.bpp = bpp
+        self.buf = bytearray(n * bpp)
+        self.pin.init(pin.OUT)
+        self.timing = timing
+
+    def __setitem__(self, index, val):
+        offset = index * self.bpp
+        for i in range(self.bpp):
+            self.buf[offset + self.ORDER[i]] = val[i]
+
+    def __getitem__(self, index):
+        offset = index * self.bpp
+        return tuple(self.buf[offset + self.ORDER[i]]
+                     for i in range(self.bpp))
+
+    def fill(self, color):
+        for i in range(self.n):
+            self[i] = color
+
+    def write(self):
+        neopixel_write(self.pin, self.buf, self.timing)

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+void esp_neopixel_write(uint8_t pin, uint8_t *pixels, uint32_t numBytes, uint8_t timing);`