Application note from Freescale Semiconductor about microinverter solution develop together with Future Electronics. Link here (PDF)
In recent years, demand for renewable energy has increased significantly. The development of devices utilizing clean energy such as solar, wind, geothermal, and fuel cells attracts more and more attention. Solar energy harvesting is developing fast and will play a more important role as a global energy source. One of the ways to capture solar energy is via photovoltaic power generation systems, which are connected to the grid through power inverters. Therefore, many companies are focusing on development of photovoltaic grid-tie inverters. Freescale offers digital signal controllers, the MC56F8xxx family, that are well suited to ongrid solar inverter designs.
Dastels writes, “In my last post I described how I hacked a 2Mbyte SPI flash onto a Trinket M0 to give it the memory space for CircutiPython of one of the M0 Express boards. This time I supersized an M0 Express board, specifically a Feather M0 Express, although the same hack should work on a Circuit Playground Express.”
This builds on a previous lab, where orthogonal frequency division multiplexing (OFDM) is used with on/off keying to send data over the channel. This scheme achieved a data rate of about 14,000 bits per second with zero errors, resulting in a figure of merit of about 14,000. The high performance design utilizes orthogonal frequency division multiplexing (OFDM) and quadrature amplitude modulation (QAM) to achieve a figure of merit much higher than the previous lab.
The overall OFDM system block diagram is shown below (taken from Professor Wagner’s course’s Scribe notes)
The gentlemen for whom I’m developing this hardware for has requested some additional functionality. The additional functionality requested is a Pulse Oximetry measurement. Pulse Oximetry is the measurement of a person’s pulse along with how much oxygen is present within their blood. It is a common measurement made by medical practitioners to ensure their patients are in good health. I suspect for the medical device, this information will be correlated with a person’s breathing to assess how well a person’s lungs are working and how much oxygen from the air is getting into their blood.
Teardown, repair and analysis of an Agilent E4443A 3Hz – 6.7GHz PSA series Spectrum Analyzer from The Signal Path:
In this episode Shahriar repairs an Agilent PSA Series Spectrum Analyzer. The instrument generates many errors during self-alignment and produces no measurements below 3.2GHz. The block diagram of the unit is thoroughly presented and various possible failure points are considered. Based on the observation of the noise floor, the most likely cause is the second LO module. The measurement of the LO power indicates that the second LO power is fall below nominal.
One of the common issues with the ZX81 is the good old RAM pack wobble. Depending on the state of your edge connectors on your ZX81 and RAM pack, it sometimes does not take much to interrupt one or more connections and crash the ZX81.
To get around this, I have done many ZX81 internal RAM upgrades, following the procedure I described in an old blog post – ZX81 Internal 16K RAM.
I had a request to do one of these, but to do it in a reversible manner, without cutting tracks.
During the academic year of 2016-2017 at McMaster University, in conjunction with Dr. DeBruin, Christina Riczu, Thomas Phan and Emilie Corcoran, we developed a compact, battery powered, 12-lead electro-cardiogram. The project won 1st place in the biomedical category at the ECE Capstone Poster Day.
Another energy meter from Texas Instruments using MSP430AFE2xx. Link here (PDF)
This application report describes the implementation of a single-phase electronic electricity meter using the Texas Instruments MSP430AFE2xx metering processors. It includes the necessary information with regard to metrology software and hardware procedures for this single chip implementation.
A good read from Atmel on their 8-bit microcontroller single-phase energy meter design. Link here (PDF)
This application note describes a single-phase power/energy meter with tamper logic. The design measures active power, voltage, and current in a single-phase distribution environment. It differs from ordinary single-phase meters in that it uses two current transducers to measure active power in both live and neutral wires. This enables the meter to detect, signal, and continue to measure reliably even when subject to external attempts of tampering.