If your design contains Microchip’s MCP79XXX series RTC chips and you are running into troubles using them, this technical brief is intended to resolve several of the commonly-asked questions regarding developing stand-alone serial interface real-time clock/ calendar devices with MCP79XXX. Similarly, there’s also another application note from Microchip which provides detail assistance and guidance in using these RTC devices.
Q&A concerning Microchip’s MCP79XXX RTC chips - [Link]
This Instructable describes building of a fun and very simple LED clock using Arduino that displays the time to the nearest half hour using LEDs.
Arduino LED clock - [Link]
Whether it´s necessary to operate a device in gloves, or you only wish the given push-button was sufficiently big and well visible, new series of round and square caps for series Multimec 5G will solve it.
Well known Dutch producer of top quality switches – company MEC, comes with novelties in a form of relatively big caps for a universal series of push buttons Multimec 5G (lifetime of 10 million cycles).
Series 5G is exceptional by the fact, that it can by equipped by a huge amount of caps of various sizes, shapes and colors. In result, you might even not say, that beneath so different push-buttons” (caps), still the same push-button switch is used.
The latest addition to the family of caps for the 5G push buttons is:
● 10R/10RF/10RM – round 30mm caps. 10R has a slightly curved surface, 10RF has a flat surface and sharp edges, and the 10RM has a metal plate with an illuminated legend.
● 10Q/10QM – square 22mm caps. 10Q has a flat surface, 10QM has a metal plate with a illuminated legend.
Multimec 5G push-buttons operate with these caps reliably – independently on the place of pressing the button (in the middle/ on the edge). Both series have optional accessory – sealing enabling to reach IP67 and a plastic spacer. Need for a spacer depends on the front panel thickness (into which a push-button is built-in) and on the overall design of a device. Overall building height is only 11mm and they´re intended to be placed in almost one level with a front panel, resulting in a very elegant look.
Homogenous illumination (backlight) of these big caps can be easily reached by means of 4 small LEDs placed on a PCB around a push-button. This also gives a possibility to freely use various LED according to your choice and to use their color combinations – for example for indication of a device status. As a standard, 7 solid colors are available and 1 transparent “frost ice” white for illumination.
Recently, we also added many other caps and push buttons from company MEC into our offer. All new additions can be found below this article.
New MEC switches can be seen even from afar - [Link]
This DIY digital clock plus thermometer is designed by Joe Farr and is based on PIC18F25K22 microcontroller. The complete construction details of this project including circuit diagrams, PCB layouts and PIC firmware are posted in his website. He developed his firmware using Proton PIC BASIC compiler, which is available for download for free for this particular PIC microcontroller. He uses DS1302 RTC for timekeeping and DS18B20 for temperature measurement. The temperature and time are displayed on four 2″ seven segment LED displays.
Another PIC-based digital thermometer and clock - [Link]
Project is based on Holteks IC HT7610A, which is a CMOS LSI chip designed for use in automatic PIR lamp, flash or buzzer control. It can operate in 3-wire configuration for relay applications. In our project we have used relay instead of Traic to connect any kind of load in output, HT7610B IC is suitable for traic and HT7610A for Relay application. The chip is equipped with operational amplifiers, a comparator, timer, a zero crossing detector, control circuit, a voltage regulator, a system oscillator, and an output timing oscillator.
Its PIR sensor detects infrared power variations induced by the motion of a human body and transforms it to a voltage variation. If the PIR output voltage variation conforms to the criteria (refer to the functional description), the lamp is turned on with an adjustable duration. The circuit doesnt required step down transformer and can work directly by applying 110V AC or 220V AC (Capacitor C7 needs to change for 220V AC (0.33uF/275V) and 110V AC (0.68uF/275V)
PIR Sensor - [Link]
Here’s a pool cleaner robot built on ATmega by Davide Gironi:
My replacement electronics it is based on ATmega8 micros.
The project is divided into two parts:
The timer contains the 220 AC to low voltage DC current, and it is out of water, his purpose is to start and stop the cleaning pool robot, which of course is inside the swimming pool.
ATmega based pool cleaner robot - [Link]
Elia wrote an article detailing his binary wrist watch project:
I have just finished my binary wrist watch project (well, the new revision anyway). I was surprised at how small I was able to make it compared to last time.
I chose to go with the “super-yellow” color LEDs as they fit the purple OSHpark PCB very nicely. The biggest challenge was actually making a good looking wrist band for the watch. I originally intended to use a design like this but it turned out that due to lack of enough para cord I had left, I went with a simpler design that I had done once before.
DIY binary wrist watch - [Link]
Freescale have introduced a new range of 3-axis accelerometers offering high sensitivity at low power consumption. According to Freescale the FXLN83xxQ family is capable of detecting acceleration information often missed by less accurate sensors commonly used in consumer products such as smartphones and exercise activity monitors. In conjunction with appropriate software algorithms its improved sensitivity allows the new sensor to be used for equipment fault prognostication (for predictive maintenance), condition monitoring and medical tamper detection applications.
High sensitivity Accelerometer Family - [Link]
Rupert Hirst writes:
A long awaited refresh, to my previous “Anti Thump” headphone output delay circuit, designed back in 2011.
The Idea behind the circuit is to introduce a small delay, during initial power up, to electrically isolate and protect equipment connected directly to an amplifier. Often, during power up, amplifiers can produce an audible thump, through speakers or headphones. This can lead to damage of the connected equipment over time.
Thumps and clicks will occur when the supply rails voltages are too low to allow the amplifier to control its output voltage.
As the circuit has an immediate disconnect when powered off, most instances of turn off thump are also dealt with, such as output capacitor discharges.
Audio: Headphone “Anti thump” delayed output rev 1.1 - [Link]
Trevor Slaton and Dawn Xiang, students from Cornell University, designed this autonomous fire extinguisher that is capable of detecting fires through photo sensors and aiming a water nozzle along two axes to extinguish the fires. Their prototype can detect and extinguish candle fires from about 1 ft. away. Their system uses two servo motors to control the vertical and horizontal position of the water nozzle and a water pump to send out a burst of water from the nozzle. The ATmega1284p microcontroller is used to control the pump as well as the servos.
Autonomous fire extinguisher - [Link]