The next issue of Circuit Cellar is due out next week! Here’s your sneak peek at what’s inside the July issue. New DFM features for PCB design tools, COVID test drone project, displays for embedded, drill position project, embedded PCs, battery monitor project and more! This 84-page magazine mixes you a refreshing cocktail of embedded technology articles for your reading pleasure.
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Here’s a sneak preview of July 2021 Circuit Cellar:
SOLUTIONS IN FOR EMBEDDED DESIGN ENGINEERS

Advances in PCB Design Tools
By Jeff Child
PCB design tools and methods continue to evolve as they race to keep pace with faster, highly integrated electronics. Along the way, the design-for-manufacturing (DFM) capabilities of today’s PCB design suites are getting more sophisticated, leveraging cloud-based collaboration and more. Circuit Cellar Chief Editor Jeff Child looks at the latest PCB design tools and technologies.
Build Your Own IoT Platform (Part 2): Connecting to Devices
By Dhairya Parikh
Dhairya continues is article series on how to build your own IoT platform. Here, in Part 2, he explains how to use MQTT and Node RED features of the platform backend you set up in Part 1 to build your first IoT project that controls relays through a Node Red dashboard.
Datasheet: Embedded PCs
By Jeff Child
Box-level embedded computers, also known as Embedded PCs, have emerged as a key technology for a variety of embedded systems markets. By using a complete, turn-key system-level solution, system developers no longer have to spend time on integrating computing sub-systems and instead can focus on their application and end-user software. This Datasheet section updates readers on these trends and provides a product album of representative of embedded PC systems.
Graphics and Displays for Embedded Systems
By Jeff Child
Displays designed for use in embedded systems keep evolving. Today’s crop of display products feature tiny form factors, sunlight-readable capabilities and embedded-friendly interfacing. Circuit Cellar Chief Editor Jeff Child delves into the latest technology trends and product developments in displays for embedded systems.
Power Analysis of ECC Hardware Implementations
By Colin O’Flynn,
Power analysis can recover cryptographickeys from implemented algorithms. In thisarticle, Colin works through such an attack on an ECC hardware implementation,showing how you can identify leakage of key material that makes an attack possible.
PROJECT ARTICLES FOR HEALTH AND ACCESSIBILITY
Building a COVID Test Drone (Part 1)
By Andrei Florian
In this two-part article series, Andrei details his CovidTestDrone project—a drone delivery system that allows individuals to receive a self-administered lower nasal swab COVID-19 test at home via a drone and then return the sample to the lab via the same drone after administering the swab. In Part 1, he describes the components, the connectivity and assisting applications for the project.
Device Duo Aids Speech for People with Disabilities
By Matthew OppenheimIn this project article, Matthew shares how he designed two devices that enable people with cerebral palsy to more easily access communication software to create speech. The units are based on the BBC micro:bit, a microcontroller development board.
MORE PROJECT ARTICES WITH ALL THE DETAILS
A Digital Amplifier for TVs: Using a Teensy 4.1
By Brian Millier
Using the same store-bought speaker system for both TV audio and playing music means dealing with unwelcome trade-offs. With that in mind, in this project article Brian taps a Teensy 4.1 to build a home-brew digital amplifier for his TV that optimized for both TV watching and playing music.
Build a Drill Position Indicator: Using Arduino Nano
By Anuj Justus Rajappa and Vairamani Kanagavel
There are times when you want to drill a hole that needs to be at a precise spot or angle. With that in mind, these authors built a position indicator to helps users position their handheld power drill so that the drill hole is oriented as required. The prototype for this battery-operated portable device was crafted using an Arduino Nano development board.
Build Your Own Battery Monitor: Counting Coulombs
By Jeff BachiochiIf you think of battery charge as “fuel” for your electronic system, “coulombs” are the “gas.” In this article, Jeff discusses the math, history and science behind Coulombs Law. He then shares the details of his project to build a battery monitor based on ADI’s LTC4150 “coulomb counter” device.