add FastLED YAML option for data rate (#1338)

* fix: FastLED SPI_DATA_RATE being truncated to 8 bits

FastLED expects SPI_DATA_RATE as an uint32_t, but we had it as uint8_t.
Fix that to avoid the data rate being truncated.

* fastled: allow specifying data rate

Previously, we've just taken the default data rate from FastLED.
However, that does not always work properly. In my case, I had a
slow level shifter that couldn't keep up with the 1 MHz data
rate default for WS2801. Long cabling might also be a reason why
one might want to reduce the data rate.

This will add a new optional "data_rate" config option where one
may specify the desired data rate as a frequency:

  light:
    - platform: fastled_spi
      chipset: WS2801
      data_pin: GPIO23
      clock_pin: GPIO22
      data_rate: 500kHz
      num_leds: 178

esphome/components/fastled_base/fastled_light.h

@@ -38,7 +38,7 @@ class FastLEDLightOutput : public light::AddressableLight {
     return *this->controller_;
   }
 
-  template<ESPIChipsets CHIPSET, uint8_t DATA_PIN, uint8_t CLOCK_PIN, EOrder RGB_ORDER, uint8_t SPI_DATA_RATE>
+  template<ESPIChipsets CHIPSET, uint8_t DATA_PIN, uint8_t CLOCK_PIN, EOrder RGB_ORDER, uint32_t SPI_DATA_RATE>
   CLEDController &add_leds(int num_leds) {
     switch (CHIPSET) {
       case LPD8806: {

esphome/components/fastled_spi/light.py

@@ -2,7 +2,8 @@ import esphome.codegen as cg
 import esphome.config_validation as cv
 from esphome import pins
 from esphome.components import fastled_base
-from esphome.const import CONF_CHIPSET, CONF_CLOCK_PIN, CONF_DATA_PIN, CONF_NUM_LEDS, CONF_RGB_ORDER
+from esphome.const import CONF_CHIPSET, CONF_CLOCK_PIN, CONF_DATA_PIN, CONF_DATA_RATE, \
+        CONF_NUM_LEDS, CONF_RGB_ORDER
 
 AUTO_LOAD = ['fastled_base']
 
@@ -21,15 +22,24 @@ CONFIG_SCHEMA = fastled_base.BASE_SCHEMA.extend({
     cv.Required(CONF_CHIPSET): cv.one_of(*CHIPSETS, upper=True),
     cv.Required(CONF_DATA_PIN): pins.output_pin,
     cv.Required(CONF_CLOCK_PIN): pins.output_pin,
+    cv.Optional(CONF_DATA_RATE): cv.frequency,
 })
 
 
 def to_code(config):
     var = yield fastled_base.new_fastled_light(config)
 
-    rgb_order = None
+    rgb_order = cg.RawExpression(config[CONF_RGB_ORDER] if CONF_RGB_ORDER in config else "RGB")
-    if CONF_RGB_ORDER in config:
+    data_rate = None
-        rgb_order = cg.RawExpression(config[CONF_RGB_ORDER])
+
+    if CONF_DATA_RATE in config:
+        data_rate_khz = int(config[CONF_DATA_RATE] / 1000)
+        if data_rate_khz < 1000:
+            data_rate = cg.RawExpression(f"DATA_RATE_KHZ({data_rate_khz})")
+        else:
+            data_rate_mhz = int(data_rate_khz / 1000)
+            data_rate = cg.RawExpression(f"DATA_RATE_MHZ({data_rate_mhz})")
     template_args = cg.TemplateArguments(cg.RawExpression(config[CONF_CHIPSET]),
-                                         config[CONF_DATA_PIN], config[CONF_CLOCK_PIN], rgb_order)
+                                         config[CONF_DATA_PIN], config[CONF_CLOCK_PIN], rgb_order,
+                                         data_rate)
     cg.add(var.add_leds(template_args, config[CONF_NUM_LEDS]))

esphome/const.py

@@ -136,6 +136,7 @@ CONF_DALLAS_ID = 'dallas_id'
 CONF_DATA = 'data'
 CONF_DATA_PIN = 'data_pin'
 CONF_DATA_PINS = 'data_pins'
+CONF_DATA_RATE = 'data_rate'
 CONF_DATA_TEMPLATE = 'data_template'
 CONF_DAYS_OF_MONTH = 'days_of_month'
 CONF_DAYS_OF_WEEK = 'days_of_week'

tests/test1.yaml

@@ -1230,6 +1230,7 @@ light:
     chipset: WS2801
     data_pin: GPIO23
     clock_pin: GPIO22
+    data_rate: 2MHz
     num_leds: 60
     rgb_order: BRG
     name: "FastLED SPI Light"