A part of a bigger project needed control circuits for up to 16 DC solenoids. Instead of wiring up a one-off prototype, I decided to design and manufacture a PCB to do the job in a scalable manner, and with a minimum of Arduino pins, so that the same circuits could be used for future high power on/off control tasks.Continue reading “Solenoid Driver PCB”
In the first part we explored the functions of this MAX7219 and how the SPI link is the key to making the device work for us.
In this part we’ll develop code to efficiently display numeric data using 7-segment and LED matrix displays.Continue reading “Using the MAX7219 in your Projects – Part 2”
The MAX7219 is a common and inexpensive IC used for controlling up to eight 7-segment LED displays (or 64 individual LEDs).
Beginners are often intimidated by how to use this versatile component with a microcontroller, turning to libraries to help them solve the problem. In most simple cases, it is more efficient to run the IC directly. Here’s what you need to know to get the job done.Continue reading “Using the MAX7219 in your Projects – Part 1”
The MPS020N0040D pressure sensor is a cheap component readily available for purchase on sites like eBay.
I recently needed to create a blow activated switch and, as I already had a few of these at hand, decided to design a minimal circuit that would provide a digital output when a threshold pressure was detected by the sensor.Continue reading “MPS020N0040D Sensor as a Pressure Activated Switch”
The LM3x series of sensors are precision, easily-calibrated, integrated circuit temperature sensors. These are ideal as a beginner sensor, only to disappoint when code is copied from somewhere, run on the MCU and the temperature readings seem to be wildly varying and incorrect. Why is this happening and what can be done about it? Read on.
Once I started using rotary encoders to provide a ‘modern’ user input experience, the elimination of panel mounted potentiometers for circuit settings and other adjustments was the next logical step. Panel mounted pots have a very different feel from the clicks of a rotary encoder, and potentiometers cannot easily be controlled by a microcontroller.
Digital Potentiometers perform the same functions as mechanical pots but can be automated. So how do they work?
I was exploring ways to make a future robot project more appealing and came across a number of articles about animated robotic eyes created to convey expression or mood. This looked like a bit of fun and quite achievable using the LED matrix modules that I have been playing with for a while. Here’s the result.
In Part 1 I described the hardware components and the functionality of the LED clock. This this part, I’ll explore the software required to implement the functionality and seamlessly manage the different user interfaces.
I wanted a create a simple project to test a few ideas and still be useful in its own right. Walking through my local IKEA store, I saw a really inexpensive analog clock (Rusch) and decided that it would provide the right vehicle for what I had in mind.
A logic analyzer is an electronic instrument that captures and displays multiple signals from a digital system or circuit on a common time base. It is a really useful tool for debugging circuits and communications links. However, the cost of brand-name logic analyzers runs into hundreds of dollars and can be really hard to justify for hobby use.
Fortunately, there is a low cost alternative using open source software and inexpensive hardware.