GPIO 21 is used by PCM to provide a data output signal to an external audio device such as a DAC chip.

Oct 9, 2017 · I suggest using raspi-gpio (sudo apt-get install raspi-gpio) to confirm at each step that the code is doing what it should: Code: Select all raspi-gpio get 20; raspi-gpio get 21

This GPIO Pinout is an interactive reference to the Raspberry Pi GPIO pins, and a guide to the Raspberry Pi's GPIO interfaces. Pinout also includes hundreds of pinouts for Raspberry Pi add-on boards, HATs and pHATs .

There are many questions on how to use the ESP32 GPIOs. What pins should you use? What pins should you avoid using in your projects? This post aims to be a simple and easy-to-follow reference guide for the ESP32 GPIOs. The figure below illustrates the ESP-WROOM-32 pinout.

The Raspberry Pi has 4 hardware PWM pins: GPIO 12, GPIO 13, GPIO 18, GPIO 19. You can have software PWM on all pins. Learn how to generate PWM signals with the Raspberry Pi:

The GPIO pins allow adding extensions to your Raspberry Pi, whether with HATs or to create circuits. The easiest way to use the GPIO pins is to create Python scripts, but Scratch or other software are also good options to consider.

Known as the four-wire serial bus, SPI lets you attach multiple compatible devices to a single set of pins by assigning them different chip-select pins. To talk to an SPI device, you assert its corresponding chip-select pin. By default the Pi allows you to use SPI0 with chip select pins on CE0 on GPIO 8 and CE1 on GPIO 7.

Sep 28, 2023 · My project's key element is a knob display which is built around an ESP32-C3, but unfortunately just one single GPIO is available for use (GPIO3). The problem is that I actually need 2 GPIO ports, one for input (GPIO3 is perfect) and one for output.

Oct 10, 2018 · Take a look at this pin diagram created by the Raspberry Pi Foundation which tells you firstly, which pins are programmable GPIO pins, in yellow, but also highlights some information about the other pins too. This diagram assumes …

May 30, 2017 · Assuming your button is connected between GPIO 21 and GND (ground), the code is nice and easy. You can download it from the Git repo as shutdown-press-simple.py. This code creates a button on GPIO 21, waits for it to be pressed, then executes the system command to power down the Raspberry Pi.