update README to document how to connect an LT8900

README.md

@@ -15,14 +15,24 @@ This is a replacement for a Milight/LimitlessLED remote/gateway hosted on an ESP
 ## What you'll need
 
 1. An ESP8266. I used a NodeMCU.
-2. A NRF24L01+ module (~$3 on ebay).
+2. A NRF24L01+ module (~$3 on ebay). Alternatively, you can use a LT8900.
 3. Some way to connect the two (7 female/female dupont cables is probably easiest).
 
 ## Installing
 
-#### Connect the NRF24L01+
+#### Connect the NRF24L01+ / LT8900
 
-This module is an SPI device. [This guide](https://www.mysensors.org/build/esp8266_gateway) details how to connect it. I used GPIO 16 for CE and GPIO 15 for CSN. These can be configured later.
+This project is compatible with both NRF24L01 and LT8900 radios. LT8900 is the same model used in the official MiLight devices. NRF24s are a very common 2.4 GHz radio device, but require software emulation of the LT8900's packet structure. As such, the LT8900 is more performant.
+
+Both modules are SPI devices and should be connected to the standard SPI pins on the ESP8266.
+
+##### NRF24L01+
+
+[This guide](https://www.mysensors.org/build/esp8266_gateway) details how to connect an NRF24 to an ESP8266. I used GPIO 16 for CE and GPIO 15 for CSN. These can be configured later.
+
+##### LT8900
+
+Connect SPI pins (CS, SCK, MOSI, MISO) to appropriate SPI pins on the ESP8266. With default settings, connect RST to GPIO 0, and PKT to GPIO 16.
 
 #### Setting up the ESP
 
@@ -61,7 +71,7 @@ The HTTP endpoints (shown below) will be fully functional at this point. You sho
 1. `PUT /settings`. Patches settings (e.g., doesn't overwrite keys that aren't present). Accepts a JSON blob in the body.
 1. `GET /radio_configs`. Get a list of supported radio configs (aka `device_type`s).
 1. `GET /gateway_traffic/:device_type`. Starts an HTTP long poll. Returns any Milight traffic it hears. Useful if you need to know what your Milight gateway/remote ID is. Since protocols for RGBW/CCT are different, specify one of `rgbw`, `cct`, or `rgb_cct` as `:device_type. Accepts a JSON blob.
-1. `PUT /gateways/:device_id/:device_type/:group_id`. Controls or sends commands to `:group_id` from `:device_id`. 
+1. `PUT /gateways/:device_id/:device_type/:group_id`. Controls or sends commands to `:group_id` from `:device_id`.
 1. `POST /raw_commands/:device_type`. Sends a raw RF packet with radio configs associated with `:device_type`. Example body:
     ```
     {"packet": "01 02 03 04 05 06 07 08 09", "num_repeats": 10}
@@ -83,13 +93,13 @@ Route (5) supports these commands. Note that each bulb type has support for a di
    * `unpair`. Emulates the unpairing process. Send as you connect a paired bulb to have it disassociate with the device ID being used.
    * `next_mode`. Cycles to the next "disco mode".
    * `previous_mode`. Cycles to the previous disco mode.
-   * `mode_speed_up`. 
+   * `mode_speed_up`.
    * `mode_speed_down`.
    * `level_down`. Turns down the brightness. Not all dimmable bulbs support this command.
    * `level_up`. Turns down the brightness. Not all dimmable bulbs support this command.
    * `temperature_down`. Turns down the white temperature. Not all bulbs with adjustable white temperature support this command.
    * `temperature_up`. Turns up the white temperature. Not all bulbs with adjustable white temperature support this command.
-   
+
 If you'd like to control bulbs in all groups paired with a particular device ID, set `:group_id` to 0.
 
 #### Examples