Interfacing AC power lines with PIC microcontrollers

Posted on by Leave a comment

Applications like automatic power factor correction, power measurement, and power line monitor require interfacing the high voltage AC power lines to microcontrollers. This application note from Microchip describes a simple method for measuring parameters from the AC power line by using only one external resistor, and is more reliable than using a bulky and expensive transformer. This method takes advantage of the input static protection circuitry that exists on I/O pins of a CMOS PIC16C5X. These protection circuits are designed to short the inputs to the power supplies when a large overvoltage is applied, thus protecting the chip from static

Read more

MAXIM’s DeepCover MAXQ1050 Secure Microcontroller to protect your embedded systems from Malware

Posted on by Leave a comment

Malware injection has become a critical threat to embedded systems. Implementing an asymmetric cryptography-based secure boot is the best protection against this class of attacks. This application note from MAXIM describes the key principles of such a secure boot and explains how to implement it with the DeepCover® MAXQ1050 secure microcontroller. Embedded systems security is a growing concern. There are new attacks on embedded systems every day, including on systems involved with health or safety. One type of attack is malware injection, the insertion of malicious code into a webpage. Once an attacker has succeeded in making a device run a

Read more

Desk panic button to get rid of annoying coworkers

Posted on by Leave a comment

Workplace is a jumble of many different personalities and we all find some difficult people to deal with. If you are often annoyed by your coworkers who just walk over to your desk and rope you into long conversations that never end when you’re on deadline, Randy Sarafon’s (from Instruclables) desk panic button will help you get rid of them without hurting their feelings. Unlike other panic buttons, this one does not summon for help in emergency. The idea is when it is pressed it calls your own phone so that you can tell your coworker that you need to answer

Read more

Chirp: An open source plant watering alarm using Attiny44A

Posted on by 3 comments

Your favorite plants need plenty of water to grow. If you keep forgetting to water your house plants you might be interested in this plant watering alarm device called Chirp. Chirp uses capacitive humidity sensing technique to measure the moisture level in the soil and alerts the user through short chirps when it is time to water the plant. Based on the amount of ambient light detected by the on-board light sensor, Chirp detects day and night condition. It is very considerate and remains silent during the night time. The project uses ATtiny44A and is licensed under CERN Open Hardware

Read more

Proper PCB grounding for mixed-signal designs

Posted on by 2 comments

Circuit board designers have always concerns about the proper way to handle grounding for integrated circuits (ICs), which have separate analog and digital grounds. This tutorial from MAXIM integrated discusses proper printed-circuit board (PCB) grounding for mixed-signal designs. For most applications a simple method without cuts in the ground plane allows for successful PCB layouts with this kind of IC. Next, we learn how to place components and route signal traces to minimize problems with crosstalk. Finally we move on to consider power supply-currents and end by discussing how to extend what we have learned to circuits with multiple mixed-signal

Read more
« Older Entries Recent Entries »