Big Timer

BigTimers

Dr. Scott M. Baker has a nice write-up about a powerful timing node for Node-Red, the Big timer:

Big Timer is (probably) the best-ever timing node for Node-Red, providing a general purpose timer as well as  handling summer/winter correctly as well as (importantly) lighting up time (for which you should provide longitude and latitude). After all you probably don’t turn the outside lights on at 6pm!! You turn them on when it gets DARK.

Project info on Scargill’s Tech blog.

Tutorial: Using the Arduino’s internal EEprom to store calibration data and LCD screen fonts

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Edward Mallon writes:

This is a follow-up to our post about using Nokia 5110 screens on three unused analog lines with shift-out. That saved me from messing with the hardware SPI bus which we reserve for the SD cards. A secondary benefit is that the code is really lean, on the order of about 250 bytes for the default font after the compile if you already have EEprom.h in the build anyway. The font, however takes up about 500 bytes, and I wanted the smallest possible footprint so that we could add live data output to loggers that are already compile near the memory limits. As it turns out, stuffing those fonts into the internal EEprom was pretty easy to do:
Using the Arduino’s Internal EEprom to Store Calibration Data & LCD Screen Fonts

More details on Underwater Arduino Data Loggers blog.

Via the comments.

Tutorial, experiment and teardown of a 24GHz Doppler radar module

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Shahriar posted a detailed analysis of a CDM324 24GHz Doppler radar module from IC Station:

Opening the module reveals a series of microwave PCB components and several active devices. A complete analysis of the module is presented. The unit is then measured and the impact of antenna impedance and power supply voltage on the output frequency is measured. The phase noise of the output signal is also measured. Using a series of servo motors, the radiation pattern of the antenna array in both azimuth and elevation is also presented.

More details on The Signal Path blog.

Check out the video after the break.

App note: Designing applications with Lithium-Ion batteries

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More Li-ion battery applications from Richtek. Link here (PDF)

Lithium-Ion batteries have several advantages when compared with other battery types: They are light weight, and energy density of lithium-ion is typically twice that of the standard nickel-cadmium. Li-Ion batteries have no memory effect, and the self-discharge is 6 ~ 8 times less compared to nickel-cadmium. The high cell voltage of 3.6 volts is often sufficient to power applications from a single cell. These properties make Li-Ion batteries very popular in modern portable electronic applications.

App note: Switching battery chargers

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App note from Richtek about several aspects of switching chargers for single cell Li-Ion batteries. Link here (PDF)

Longer battery life and shorter charging times are some of the challenges in battery management in modern hand-held applications like Smart-Phones, Tablet PCs, POS and other portable equipment.

Devices with powerful processors are more power hungry and require larger capacity batteries to guarantee battery life. To quickly charge large capacity batteries, powerful high current chargers are needed. Linear chargers have too limited charge current capability for this purpose, so switching charger topology has to be adopted.

Grbl_ESP32 CNC development board

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Bart Dring has designed a development board for using CNC on Grbl ESP32:

This is a Grbl_ESP32 CNC Development board. This is a quick and easy way to use and test CNC on the ESP32 controller.
Grbl is a great CNC firmware that has been around for nearly a decade. It was originally designed for the Arduino UNO and basic 3 axis CNC routers, but it has been ported to other CPUs and was the basis for many other CNC and 3D printer firmwares.

Project info at Buildlog.Net Blog. It’s also up on Tindie.

Building an Atari Punk console

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Øyvind shows you how to easily make a DIY Atari Punk console:

Do you want a fun and easy-to-build circuit? Here’s the simple, but fun Atari Punk Console – with schematics and parts list. It’s a quick build, so you can easily build it during an evening.
It takes its name from the old Atari computers of the 80s because it makes similar sounds.

More details on Build Electronic Circuits homepage.

Check out the video after the break.

App note: AC ripple current calculations solid tantalum capacitors

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Application note from Vishay on power and voltage limitations of solid tantalum capacitors for both low and high frequency applications. Link here (PDF)

Solid tantalum capacitors are preferred for filtering applications in small power supplies and DC/DC converters in a broad range of military, industrial and commercial systems including computers, telecommunications, instruments and controls and automotive equipment. Solid tantalum capacitors are preferred for their high reliability, long life, extended shelf life, exceptional stability with temperature and their small size. Their voltage range is 4 to 50 volts for the most common types. Tantalum chip capacitors for surface mount applications are manufactured in very small sizes and are compatible with standard pick-and-place equipment.

App note: Electrolytic capacitor lifetime estimation

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Lifetime estimation methods for elcap app note from Jianghai. Link here (PDF)

Aluminum Electrolytic Capacitors (“alu-elcaps”, “elcaps”) are essential for the function of many electronic devices. Ever increasing for enhanced efficiency, the expanding utilization of renewable energy and the continuous growth of electronic content in automotive applications have driven the usage of these components.

In many applications, the lifetime of electronic devices is directly linked to the lifetime of the elcaps inside. To ensure reliable operation of electronic devices for a defined period, a thorough knowledge of the vital properties of elcaps is mandatory.

The present article outlines the construction of elcaps and explains related terms like ESR, ripple current, self-heating, chemical stability, and lifetime. Two estimation tools for obtaining elcap lifetime approximations in an application are introduced and illustrated by an example.

Open source RISC – Eclipse with RISC-V on the SiFive HiFive1 board

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Erich Styger writes:

Open Source software has been around for decades. But open source on hardware especially microcontroller is not much a reality these days. But there is something which might change this: RISC-V is a free and open RISC instruction set architecture and for me it has the potential to replace some of the proprietary architectures currently used. RISC-V is not new, but it gets more and more traction in Academia (no surprise). Not only because it is open: Think about all the recent security issues with proprietary architectures: Spectre, Meltdown, and Foreshadow just be the most recent one.
I wanted to play with RISC-V for over a year, but finally a week ago I did one of these “hey, let’s buy that board” thing again. Sometimes these boards get on a pile to wait a few weeks or longer to get used, but that one I had to try out immediately :-).

More details on MCU on Eclipse site.