# ESP32 Basic

***
## ESP32 pinout

## GPIO
### define the GPIO pin

#define LED1 13 // GPIO Pin 13
#define BTN1 12 // GPIO Pin 12

### Set-up the GPIO Pin Mode
* `pinMode(pin, mode)`
* mode
* `OUTPUT`
* `INPUT`
* `INPUT_PULLUP`

#### Example

void setup(){ 
    // set pin 13 as output
    pinMode(LED1, OUTPUT); // usually inside setup()
    // set pin 12 as input
    pinMode(LED1, INPUT); // usually inside setup()
}

### Read from the pin
* `digitalRead(pin);`
* Example
* `digitalRead(BTN1);`

### Write to the pin
* `digitalWrite(pin, state);`
* state:
* `HIGH`
* `LOW`
* Example
* `digitalWrite(LED1, HIGH);`
***
## PWM
* `analogWrite(pin, value);`
* value is between 0 to 255
* No need to set/modify the pre-scaler and counter values

## UART
* Breifly talk about what is UART
* Require 2 pins for Input and Output
* TX , Transmit
* RX , Receive
* Connection
* TX -> RX
* RX -> TX
* Output bit-stream
* usually encoded as a byte
* `unsigned char`
* `uint8_t`
* Asychronized Communciation
* Object `Serial` is existed
### Set-up the UART with baudrate

Serial.begin(115200);
// Serial1 be uart1

#### Example

Serial.printf("Hello World");

***

# Reference :
https://lastminuteengineers.com/esp32-pinout-reference/