Category

Using libgpiod to detect input events

2021-05-17 hardware gpio

One of the most fundamental requirements for GPIO is the ability to execute user defined code when an external event has happened. This is typically ... Read More

GPIO Input with libgpiod

2021-05-10 hardware raspberry-pi

We can use the libgpiod library to configure a GPIO line as input and read it’s value. We’ll create a switch circuit so we can test the ... Read More

Blinking and LED with libgpiod

2021-05-03 hardware raspberry-pi

In the previous post we introduced libgpiod. In this post we’ll use the command line tools to blink and LED. Finally, we’ll write some C ... Read More

The new GPIO Interface on the Rasberry PI: libgpiod

2021-05-02 hardware gpio

The GPIO Sysfs Interface is deprecated. The deprecated Sysfs would interact with GPIO using the /sys/class/gpio pseudo-filesytem. The Application ... Read More

Raspberry Pi SPI Explained

2021-04-21 hardware raspberry-pi

This post attempts to provide some finer details when using SPI on Raspberry Pi as it pertains to using the Chip Select pins and multiple SPI ... Read More

Implementing a Timeout for a read in C

2021-04-12 c

Need to wait a specified amount of time for a read call to return before giving up and continuing on? In Unix when we read from a file we can have a ... Read More

Audio Clip Capture by Threshold

2021-04-10 hardware raspberry-pi alsa

Here is a command line tool to capture audio clips based on a threshold. The setup is a microphone attached to a Raspberry Pi. I used multiple ... Read More

Movement in Emacs

2021-04-06 emacs

A little cheat sheet for movement in emacs. Tried to capture all the ways you can move up, down, left and right in a buffer. Moving by Character and ... Read More

BPSK Receiver Theory

2021-02-17 dsp psk

Let’s look at some BPSK Receiver Theory. This is the 3rd post in the PSK Series. We’ll cover the theory before we go into the ... Read More

BPSK Transmitter Implementation

2021-01-24 dsp psk

In the previous post we discussed BPSK Transmit Theory. This post will discuss the implementation of it. This implementation will be in the C ... Read More