Check out the project page for ongoing development for emonPi Raspberry Pi Energy Monitoring Shield, on OpenEnergyMonitor. (Also follow the posts on the project blog here.)
For a while now I have been working on developing a Raspberry Pi energy monitoring shield. Here is a preview of the first prototype design.
The emonPi is not designed to totally replace the emonTx V3, but rather to complement it. I see the emonPi fulfilling two applications:
As a low cost Raspberry Pi add-on shield to make all-in-one home energy monitoring unit based on the Raspberry Pi. We will produce a version of the emonPi board on it’s own (without enclosure, HDD and LCD), maybe even with just SMT components ready assembled (like the Arduino Lenoardo) to being the cost down further.
As a high quality, robust and nicely enclosed stand-alone energy monitoring unit and web-connected base station with LCD status display, built in hard-drive for local logging and backup. The emonPi has also been designed to be perfect for installers of heat-pump monitoring systems which require many temperature sensor wired up (see temperature sensing part of my forum post update) as well as power monitoring.
The emonPi has got an option for RFM12B / RFM69CW radio to enable it also to act as an emonBase, receiving date from other wireless nodes such as emonTH (room temperature and humidity node), emonTx V3 (energy monitoring node) and transmitting the current time to the emonGLCD LCD display.
Since the emonPi is an energy monitor sensing node and remote posting base station all-in-one and coupled with a status LCD this should make system setup, installation and debugging easier. The emonPi should also be great for remote administration since with the correct network config the Raspberry Pi can be accessed remotely, log files checked and even upload Arduino sketch firmware onto the emonPi’s ATmega328….
emonPi Raspberry Pi Energy Monitoring Shield - [Link]
Any experienced engineer will tell you that power supply design is not a trivial exercise and bad design often leads to poor system reliability. For more than a decade now engineers have been able to use the Texas Instruments WEBENCH design tools to streamline power supply design.
The online software allows designers to quickly create, optimize and simulate a complete design using calculation algorithms and the SPICE simulator tool provided by the WEBENCH Power Designer software. Careful PCB layout can also be critical for power supply performance. Texas Instruments have now added PCB Export to the WEBENCH suite of design tools. This allows engineers to run electrical and thermal simulations to characterize their designs, create a power supply PCB layout, and export it to Altium, Cadence Design Systems, Inc., CadSoft Computer, Mentor Graphics and RS Components CAD platforms.
According to the press release WEBENCH Power Designer together with PCB Export will help reduce PCB board design time from hours to minutes and take into account best layout practices to reduce noise and thermal issues.
WEBENCH now with PCB Export - [Link]
sameer @ sgprojects.co.in writes:
Water level indicator plays a vital role in the world of water saving technology. It indicates five different level of water in a tank mostly used in housing water tank,cooler tank etc. The circuit is based on the microcontroller AT89S52 which is brain of the whole system. A CMOS IC4049 is used as a water sensor which provides input signals for the MCU. The output of microcontroller is connected to an LCD and a buzzer. LCD shows the water level in five steps. When the tank gets full of water,an alarm sounds.
Water Level Indicator using LCD - [Link]
An all-in-one breadboard with Oscilloscope, Spectral Display, Function Generator, and Power Supply.
We are excited to bring a low-cost audio range electronics development board to classrooms, labs, small businesses, and techno-geeks everywhere. This idea has been bouncing around in our family for many years and now the technology has caught up to make it a reality at a price that schools and individuals can afford. We have paired a traditional prototype board (or breadboard) with an electronics suite so that the experimenter does not have to purchase the expensive electronics test equipment needed during development. It is everything we wish we had when we were learning about circuits on a breadboard.
Bakerboard: The Educational Breadboard with More - [Link]
This article details an AC-based continuity tester designed for frontline test and repair jobs. The circuit provides a simple GO/NO-GO test for localizing faults in multicore cables. Open circuits are more likely at connector ends. By identifying the faulty end, the AC continuity tester allows you to open and repair the correct cable end. This action avoids the risk of damaging a good connector by opening it up. This approach is also useful for testing an installed cable with ends at different locations.
The schematic illustrates a circuit for a continuity tester that injects an AC signal on one cable wire and then looks for the absence of capacitive coupling on the other wires. One end of a bad cable typically shows good AC continuity, while the other end typically has one or more connector pins with no AC continuity. Because a short in the cable appears as a good connection, the operator can easily confirm that the tester is operating correctly by simply shorting its test leads together.
The left side of the circuit uses a low-power dual comparator (MAX9022) to form a relaxation oscillator operating at approximately 155kHz. It produces a peak-to-peak output signal approximately equal to the supply voltage, which is fed to a connector of the cable under test. The right side of the circuit processes any AC signal picked up by the inter-lead capacitance. That AC signal is first rectified by a pair of silicon diodes, and then integrated on storage capacitor C5. The bleed resistor (R5) provides some noise immunity and helps to reset the capacitor between tests.
The output resistor (R4) and input capacitor (C4) provide limited circuit protection. The circuit indicates OPEN for any test-cable capacitance below 100pF. (Thus, a standard 2m IEC mains test lead, whose typical lead-to-lead capacitance is 200pF, would test OK.) The circuit is also immune to false triggers caused by the 60Hz pickup from power lines.
Because the typical current draw of this low-power circuit is less than 40μA most of the time, the circuit can be powered by three AA or AAA 1.5V pencil batteries.
Many low-cost alternatives are available for the output device (e.g., a DC-activated piezoelectric buzzer), and most alternatives feature a suitably wide operating voltage range. The 100nF capacitors are standard ceramic decoupling capacitors, and the circuit contains no critical passive components. The comparator’s high-side drive is better than its low-side drive, so it should be used to source (rather than sink) current to the indicator device. Diodes D1 through D3 are silicon diodes.
AC Continuity Tester - [Link]
Jan_Henrik @ instructables.com writes:
in this Instructable I want to show you, how you can program your Arduino with your Android device. It is very simple and cheap. Also it allows us to program our Arduino where ever we want, this is usefull for permanently installed Arduino boards, like in light controllers…
Program your Arduino with an Android device - [Link]
Have no fear… even if this project sounds complex, you’ll easily learn in this article many things about high speed electronics and PCBs. In fact, my goal here is to teach you some basics about all the new problems that arise when you’re dealing with GHz signals
Amplifying nanosecond pulses for quantum physics experiments - [Link]
Summer offer of company Wago brings us a price-gainful set of favorite clamps together with a quality replica of official ball of incoming championship – Brazuca.
Opportunity to gain a souvenir of a great sport event usually lasts only some time. DVD, poster, mascot and other “gift items” are usually valued and required things. But perhaps the most precious is something, what we can use ourselves. In this case it is a quality replica of the ball Brazuca, which is as known an official ball of world football championship Brasil 2014.
How to gain it? All that is necessary is that you also need well-known and well-proven installation terminal blocks series 2273. At purchase of a special Wago set 887-119 you´ll gain 400 pcs 2273-203, 400 pcs 2273-205, high-quality replica of the ball Brazuca and a practical pump with a needle valve usable also for other balls.
For the price of 89 Eur you´ll gain 800 pcs of installation terminal blocks and a valuable present usable to keep yourself fit :).
Take use of a special offer to have your own “Brazuca” - [Link]
Scheme-It is an online schematic and diagramming tool that allows anyone to design and share electronic circuit diagrams. Walk through how to create your own diagrams with the electronic symbol library and how to export and share your drawings.
Scheme-It – Online schematic and diagramming tool - [Link]