Add ESP32 related docs

Author: sandeepmistry

API.md

@@ -21,6 +21,8 @@ Returns `1` on success, `0` on failure.
 
 ### Set pins
 
+#### MCP2515
+
 Override the default `CS` and `INT` pins used by the library. **Must** be called before `CAN.begin(...)`.
 
 ```arduino
@@ -31,8 +33,22 @@ CAN.setPins(cs, irq);
 
 This call is optional and only needs to be used if you need to change the default pins used.
 
+#### ESP32
+
+Override the default `CTX` and `CRX` pins used by the library. **Must** be called before `CAN.begin(...)`.
+
+```arduino
+CAN.setPins(rx, tx);
+```
+ * `rx` - new CRX pin to use, defaults to `4`
+ * `tx` - new CTX pin to use, defaults to `5`.
+
+This call is optional and only needs to be used if you need to change the default pins used.
+
 ### Set SPI Frequency
 
+**MCP2515 only**
+
 Override the default SPI frequency of 10 MHz used by the library. **Must** be called before `CAN.begin(...)`.
 
 ```arduino
@@ -44,6 +60,8 @@ This call is optional and only needs to be used if you need to change the defaul
 
 ### Set Clock Frequency
 
+**MCP2515 only**
+
 Override the default clock source frequency that is connected to the MCP2515. **Must** be called before `CAN.begin(...)`.
 
 ```arduino

README.md

@@ -7,6 +7,7 @@ An Arduino library for sending and receiving data using CAN bus.
 ## Compatible Hardware
 
 * [Microchip MCP2515](http://www.microchip.com/wwwproducts/en/en010406) based boards/shields
+* [Espressif ESP32](http://espressif.com/en/products/hardware/esp32/overview)'s built-in [SJA1000](https://www.nxp.com/products/analog/interfaces/in-vehicle-network/can-transceiver-and-controllers/stand-alone-can-controller:SJA1000T) compatible CAN controller with an external 3.3V CAN transceiver
 
 ### Microchip MCP2515 wiring
 
@@ -25,6 +26,19 @@ An Arduino library for sending and receiving data using CAN bus.
 
 **NOTE**: Logic level converters must be used for boards which operate at 3.3V.
 
+### Espressif ESP32 wiring
+
+Requires an external 3.3V CAN transceiver, such as a [TI SN65HVD230](http://www.ti.com/product/SN65HVD230).
+
+| CAN transceiver | ESP32 |
+| :-------------: | :---: |
+| 3V3 | 3V3 |
+| GND | GND |
+| CTX | 5 |
+| CRX | 4 |
+
+`CTX` and `CRX` pins can be changed by using `CAN.setPins(rx, tx)`.
+
 ## Installation
 
 ### Using the Arduino IDE Library Manager
@@ -51,4 +65,4 @@ See [examples](examples) folder.
 
 ## License
 
-This libary is [licensed](LICENSE) under the [MIT Licence](http://en.wikipedia.org/wiki/MIT_License).
+This library is [licensed](LICENSE) under the [MIT Licence](http://en.wikipedia.org/wiki/MIT_License).

library.properties

@@ -3,7 +3,7 @@ version=0.0.0
 author=Sandeep Mistry <[email protected]>
 maintainer=Sandeep Mistry <[email protected]>
 sentence=An Arduino library for sending and receiving data using CAN bus.
-paragraph=Supports Microchip MCP2515 based boards/shields.
+paragraph=Supports Microchip MCP2515 based boards/shields and the Espressif ESP32's built-in SJA1000 compatible CAN controller.
 category=Communication
 url=https://github.com/sandeepmistry/arduino-CAN
 architectures=*