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How many GPIO pins does the ESP8266 have?
Usable pins. The ESP8266 has 17 GPIO pins (0-16), however, you can only use 11 of them, because 6 pins (GPIO 6 – 11) are used to connect the flash memory chip.
What kind of voltage does the ESP8266 microcontroller use?
The ESP8266 is a 3.3V microcontroller, so its I/O operates at 3.3V as well. The pins are not 5V tolerant, applying more than 3.6V on any pin will kill the chip.
What’s the maximum voltage of a GPIO pin?
That GPIO is called ADC0 and it is usually marked on the silkscreen as A0. The maximum input voltage of the ADC0 pin is 0 to 1V if you’re using the ESP8266 bare chip. If you’re using a development board like the ESP8266 12-E NodeMCU kit, the voltage input range is 0 to 3.3V because these boards contain an internal voltage divider.
What happens when the ESP8266 is pulled low?
The ESP8266 can be prevented from booting if some pins are pulled LOW or HIGH. The following list shows the state of the following pins on BOOT: GPIO2: pin is high on BOOT, boot failure if pulled LOW GPIO1: pin is high at BOOT, boot failure if pulled LOW There are certain pins that output a 3.3V signal when the ESP8266 boots.
ESP8266 has 17 GPIO pins (0-16), however, you can only use 11 of them, because 6 pins (GPIO 6 – 11) are used to connect the flash memory chip. This is the small 8-pin IC right next to the ESP8266. If you try to use one of these pins, you might crash your program.
Why is my ESP8266 not booting properly?
The ESP8266 can be prevented from booting if some pins are pulled LOW or HIGH. The following list shows the state of the following pins on BOOT: There are certain pins that output a 3.3V signal when the ESP8266 boots.
Where to place a capacitor on the ESP8266?
Place a 10µF capacitor between pin 2 (V out) and ground. Watch the polarity! Place a 10µF capacitor between pin 3 (V in) and ground. Connect pin 2 to the 3.3V or V CC of the ESP8266. Connect pin 3 to a 5V power source, a USB port, for example.
How to change the frequency of the ESP8266?
The frequency can be changed by using analogWriteFreq (new_frequency);. new_frequency should be between 100 and 1000Hz. Just like on an Arduino, you can use analogRead (A0) to get the analog voltage on the analog input. (0 = 0V, 1023 = 1.0V).
What are the GPIO pins used for in SPI?
Pin12: MTCK is an input/output pin labeled as GPIO13 and it is used in SPI as Master-Out Slave-In pin (SPI_MOSI) as well as used in UART as Clear To Send pin (UART_CTS). Pin13: MTDO is an input/output pin labeled as GPIO15 and it is used in SPI as Chip Select pin (SPI_CS) as well as used in UART as Request To Send pin (UART_RTS).
What kind of peripherals do ESP8266 peripherals use?
ESP8266 12E NodeMCU Development Board pinout NodeMCU development board has a total 30 pins in which 14 pins are active, uses ESP-12 module, onboard reset and flash button, 3.3 voltage regulator, Micro USB, USB to UART Bridge and some other components. ESP8266 Peripherals The ESP8266 have the following peripherals: