[*] [-] [-] [x] [A+] [a-]  
[l] at 8/22/19 5:45pm

tmpFB70-600

Peter Scargill’s Script:

Regular readers will know about the script that Aidan Ruff and I originally developed to put Node-Red and several other packages onto the Raspberry Pi for our own home control purposes. This has been developed with help from several people and in particular my friend Antonio “Mr Shark”.
WELL – here is the script which is intended to help set-up certain Raspbian, Debian or similarly-based SBCs which now includes logging and handling Raspbian Buster (tested on Raspberry Pi 2, 3, 3B+, 4 with Stretch, 3B+ and 4 with Buster). As well as it’s original purpose of setting up a Raspberry Pi, the script also runs well with several other boards. See right hand side of the above image for what the script does, given a basic operating system install. We currently suggest NOT using this with DIET PI, original Pi or the Raspberry Pi Zero as we are no longer testing either and the latter pair are just TOO SLOW.

See the full post on Scargill’s Tech Blog.

Check out the video after the break.

[Category: code, R-Pi, Node-RED, Raspberry Pi]

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[l] at 8/21/19 10:46am

tinyFINITY_DSC00057-600

tinyOSD and the tinyFINITY,  a tiny open source video transmitter with integrated graphic OSD from fishpepper.de

As I like fully integrated solutions I started to work on a new PCB design that includes a RTC6705 video transmitter and my tinyOSD into one tiny 16x16mm board called tinyFINITY. The image shows a preliminary version where I tested a surface mounted ceramic antenna instead of the usual wire or whip-antenna (which was rejected in later designs because of the poor performance)

Project info at fishpepper.de  and the GitHub repository here: tinyOSD and tinyFINITY.

Check out the video after the break.

[Category: open source, DIY, OSD]

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[l] at 8/20/19 7:56am

terrible 3 cent MCU

Tim (cpldcpu) writes:

Like many others, I was quite amazed to learn about a microcontroller sold for only 0.03 USD via the EEVblog last year. How was this possible? Many assumed this was a fire sale of an old product. Digging a bit further, it became apparent that there is an entire market segment of ultra-low-cost microcontrollers. Almost all of them are products of rather unknown companies from China or Taiwan. This write up summarizes my findings in this rather peculiar niche.

See the full post on Tim’s blog.

[Category: documentation, MCU, microcontroller]

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[l] at 8/19/19 5:37pm

PS

Kerry Wong did a teardown of an EC600-90 electrophoresis high voltage power supply:

Electrophoresis power supplies are commonly found in biology and other life sciences laboratories. These power supplies are usually capable of supplying high voltages and high currents required for gel electrophoresis–a method used for separating DNA, RNA and other protein fragments based on their size and charge. There are many used electrophoresis power supplies out there in the second hand market and can be bought quite cheaply. I am curious whether these electrophoresis power supplies are suitable for electronics lab use as a lab grade high voltage power supply can be quite expensive. So I recently picked up one from eBay to take a look.

See the full post on his blog.

Check out the video after the break.

[Category: power supply, Teardowns, teardown]

[*] [-] [-] [x] [A+] [a-]  
[l] at 8/18/19 11:00am

an_silabs_an856

Good read on this app note from Silicon Labs comparing their low power but obsolete timer. Link here (PDF)

The 555 timer is the workhorse of ICs, with close to a billion of them manufactured every year. Introduced in 1972, the 555 is still in widespread use because of its ease of use, reasonable price, and good stability. It can be found in a wide variety of applications for oscillation, timing and pulse generation. But what if you need a timer IC for ultralong life, low-frequency battery-powered/portable applications where a low supply current is a requirement? Is the CMOS555 timer your best option?

[Category: app notes, 555 timer, app note, Silicon Labs]

[*] [-] [-] [x] [A+] [a-]  
[l] at 8/18/19 7:30am

an_silabs_an857

Q-pump an alternative to inductor charge pump boost regulator for low power and sleepy microcontroller from Silicon Labs. Link here (PDF)

In the switch-mode power supply world, capacitor-based charge pumps (or Q-pumps) generally aren’t useful for heavy lifting, but work well in niche micropower applications where space is at a premium. They work best in applications where the output voltage is an integer multiple of the input voltage, which are operating points that result in peak efficiency. However, they can also shine when powered from a variable input like a battery, particularly when quiescent battery drain is more important than heavy-load efficiency. This might be the case when powering a microcontroller that spends most of its life sleeping.

[Category: app notes, app note, charge pump, Silicon Labs]

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[l] at 8/16/19 5:40pm

BP

Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week:

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • We’ll contact you via Facebook with a coupon code for the PCB drawer.
  • Limit one PCB per address per month, please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

[Category: Free PCBs, free PCB drawer]

[*] [-] [-] [x] [A+] [a-]  
[l] at 8/16/19 5:33pm

20150705_032526

Ashhar Farhan (VU2ESE) made an Arduino based sweeper for ham radio homebrewing, that is available on GitHub:

The Sweeperino a very useful Arduino based test instrument. It is the following:
*A very stable, low noise signal generator from 4 MHz to 160 MHz without any spurs
*A high precision power meter with 90 db with 0.2db resolution
*A sweeper that can be your antenna analyzer, plot your crystal or band pass filter through the PC
*It fits in your jacket
*It can be assembled in an evening
*Costs about $50 in new parts

See the full post on VU2ESE’s radio experiments blog.

[Category: Arduino, tools, DIY tools, test instrument]

[*] [-] [-] [x] [A+] [a-]  
[l] at 8/15/19 9:17am

micro24_schematic_dk7ih_outside3

Peter Rachow (DK7IH) built a 14MHz SSB QRP Micro-transceiver into a cigarette packet size case:

This article describes the “Cigarette Pack” SSB QRP transceiver” for 14MHz that I first had mentioned some months before. Recently, when taking it from the shelf, the transceiver dropped to the floor and was severely damaged. This lead to serious defects in the front panel area, the main frame, the cabinet and so on. The interior parts were, luckily, not affected by the crash. So, I had to revise the whole radio, make a new front panel and cabinet, ply the frame straightly (as far as possible) and so on. This is the full description of the rig now to complete the files here. The good news: The radio is fine again and fully operational!  And the even better news: I still have not started smoking!

See the full post on Amateur Radio Engineering Projects blog.

[Category: DIY, RF, homebrew, SSB transceiver]

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[l] at 8/14/19 4:39pm

In this video Adam 9A4QV demonstrates his 2.4 GHz homemade helical feed for the QO-100/Es’Hail-2 satellite.

Via RTL-SDR.

[Category: DIY, antenna, satellite]

[*] [+] [-] [x] [A+] [a-]  
[l] at 8/11/19 11:00am

an_microchip_TB3221

Presenting the usage of Core independent paripheral of PICs in this app note from Microchip. Link here (PDF)

It is possible to find out whether a measured signal is below or above a certain value/reference using a single comparator. But, what if the desired interval is between two values, the undervoltage and overvoltage protection?

The most convenient and fastest solution is to use two comparators and two references. The results are analyzed to decide which of the three intervals houses the measured signal. Using an Analog-to-Digital Converter (ADC) and core post-processing will yield the same result, but the process is slower and dependent on core availability.

[Category: app notes, app note, microchip, PIC]

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[l] at 8/11/19 7:05am

an_microchip_AN3018

Here’s an app note about PSRR of LDO from Microchip. Link here (PDF)

The Power Supply Rejection Ratio is the ability of a device, such as a Low Dropout Voltage regulator, to reject the various perturbations that can be found in its input supply rail by providing a greatly attenuated signal at the output. Generally, the main source of the perturbation will be the output ripple of the DC/DC converters that typically power LDOs.

High PSRR LDOs are recommended for powering line ripple sensitive devices such as: RF applications, ADCs/DACs, FPGAs, MPUs, and audio applications.

One important clarification must be made: PSRR is NOT the same with output noise. PSRR is a measure of rejection. It shows what the part will output based on the given input.

[Category: app notes, app note, LDO regulator, microchip]

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[l] at 8/8/19 5:38pm

board-built-600

Andy Brown designed and built an STM32G081 development board:

I’ve been an avid user of ST’s F0 series ever since it was launched. The 48MHz Cortex M0 is almost always the perfect MCU for every project that I tend to build and it’s so easy to program and debug that, for me, it’s the default answer to ‘which MCU should I use for this project?’ So when I noticed that ST had launched a ‘G0’ range I just had to have a closer look.

See the detailed writeup and download the Gerber files on Andy’s Workshop.

Check out the video after the break.

[Category: dev boards, development board, STM32]

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[l] at 8/6/19 5:55pm

esp8266-web-server-thumbnail-600

A detailed instructions of how to build an ESP8266 Web Server using NodeMCU firmware:

This tutorial is a step-by-step guide that shows how to build a standalone ESP8266 Web Server that controls two outputs (two LEDs). This ESP8266 NodeMCU Web Server is mobile responsive and it can be accessed with any device with a browser in your local network.

Via Random Nerd Tutorials.

Check out the video after the break.

[Category: tutorials, ESP8266, how-to, NodeMCU]

[*] [+] [-] [x] [A+] [a-]  
[l] at 8/5/19 5:48pm

dataflash

David Johnson writes:

This is a small board that plugs into one of the headers on an Arduino Uno or other board to provide 4Mbytes of non-volatile storage
It works with either 5V or 3.3V boards, and is based on the low-cost 4Mbyte Winbond W25Q32FVSIG DataFlash chip. It is ideal for applications such as data logging, playing audio samples, and storing text.
I also describe a simple DataFlash library to interface to the board.

More details on Technoblogy.

[Category: Arduino, Chips]

[*] [+] [-] [x] [A+] [a-]  
[l] at 8/4/19 11:00am

an_osram_AN040

Another application note from OSRAM on different LED circuit design failure mode. Link here (PDF)

In recent years, Light Emitting Diodes (LEDs) have become a viable alternative to conventional light sources. The overriding advantages long life, high efficiency, small size and short reaction time have lead to the displacement, in ever increasing numbers, of incandescent bulbs. One of the markets where this change has become most evident is Automotive, where LEDs are used now not only for backlighting dashboards and switches, but also for exterior illumination in Center High Mounted Stop Lights (CHMSL), Rear Combination Lamps (RCL), turn signals and puddle lighting.

Despite the long life and low failure rates of LEDs, cars can be found, on occasion, with failed LEDs in their CHMSL. Most often this is due to a flawed circuit design wherein the LEDs were allowed to be overdriven. It is with that supposition in mind that this application note is written: to identify, characterize and comment on LED behavior and failure modes in serial and matrix circuits.

[Category: app notes, app note, automotive, LEDs, OSRAM]

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[l] at 8/4/19 7:15am

an_osram_AN043

App note from OSRAM describing the behaviour of LEDs in respect to brightness by varying the current and to suggest solutions for avoiding negative influence for the application. Link here (PDF)

In the design of a driving circuit for LEDs, the dimming behaviour is an important topic to fulfill the end customer requirements. The behaviour of the LEDs in respect to brightness is investigated by varying the current and solutions for avoiding negative influence for the application are suggested.

[Category: app notes, app note, LEDs, OSRAM]

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[l] at 8/2/19 4:47pm

bt-dac-final

Sami Pietikainen has written an article detailing the build of his Bluetooth DAC using Raspberry Pi Zero W:

My car comes with a built-in Bluetooth hands-free but unfortunately it does not support audio streaming. Luckily there is an AUX input available which uses a regular 3,5 mm jack. Perfect opportunity for a DIY project. I built the Bluetooth DAC using Raspberry Pi Zero W and a DAC hat. This post depicts the details of this project.

See the full post on Page Fault Blog.

[Category: DIY, R-Pi, DAC, Raspberry Pi Zero]

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[l] at 8/1/19 9:25am

Here’s a DIY vacuum pick-up tool for SMD components:

This video describes a DIY Vacuum Pick-up tool for picking and placing parts from an SMD component tape. The basic design for this tool involves using a vacuum pump and a solenoid to control the vacuum to a handpiece under control of a foot pedal.

Via SDG Electronics.

[Category: DIY, tools, DIY tools, SMD soldering]

[*] [+] [-] [x] [A+] [a-]  
[l] at 7/31/19 5:56pm

5300-chips-600

Ken Shirriff did teardown of a 1970s PROM chip:

The MMI 5300 was a memory chip from the early 1970s, storing 1024 bits in tiny fuses.1 Unlike regular RAM chips, this was a PROM (Programmable Read-Only Memory); you programmed it once by blowing fuses and then it held that data permanently.

See the full post on his blog.

[Category: Chips, Teardowns, MMI 5300, PROM chip]

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[l] at 7/30/19 5:27pm

BP

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

[Category: Free PCBs, free PCB drawer]

As of 8/23/19 8:09am. Last new 8/21/19 11:18am.

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