Component Shelf Life: How To Use All That Old Junk

April 23, 2019 by 31 Comments

There are two types of Hackaday readers: those that have a huge stock of parts they’ve collected over the years (in other words, an enormous pile of junk) and those that will have one a couple of decades from now. It’s easy to end up with a lot of stuff, especially items that you’re likely to use in more than one design; the price breakpoints at quantities of 10 or 100 of something can be pretty tempting, and having a personal stock definitely speeds the hacking process now that local parts shops have gone the way of the dinosaur. This isn’t a perfect solution, though, because some components do have shelf-lives, and will degrade in some way or another over time.

If your stash includes older electronic components, you may find that they haven’t aged well, but sometimes this can be fixed. Let’s have a look at shelf life of common parts, how it can be extended, and what you can do if they need a bit of rejuvenation.

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The Embroidered Computer

January 16, 2019 by 5 Comments

By now we’ve all seen ways to manufacture your own PCBs. There are board shops who will do small orders for one-off projects, or you can try something like the toner transfer method if you want to get really adventurous. One thing we haven’t seen is a circuit board that’s stitched together, but that’s exactly what a group of people at a Vienna arts exhibition have done.

The circuit is stitched together on a sheet of fabric using traditional gold embroidery methods for the threads, which function as the circuit’s wires. The relays are made out of magnetic beads, and the entire circuit functions as a fully programmable, although relatively rudimentary, computer. Logic operations are possible, and a functional schematic of the circuit is also provided. Visitors to the expo can program the circuit and see it in operation in real-time.

While this circuit gives new meaning to the term “wearables”, it wasn’t intended to be worn although we can’t see why something like this couldn’t be made into a functional piece of clothing. The main goal was to explore some historic techniques of this type of embroidery, and explore the relationship we have with the technology that’s all around us. To that end, there have been plenty of other pieces of functional technology used as art recently as well, but of course this isn’t the first textile computing element to grace these pages.

Thanks to [Thinkerer] for the tip!

 

LED “Candle” Gets The 555 Treatment

September 5, 2018 by 29 Comments

Regular readers may recall we recently covered a neat Arduino trick that allowed you to “blow out” an LED as if it was a candle. The idea was that the LED itself could be used as a rudimentary temperature sensor, and the Arduino code would turn the LED on and off when a change was detected in its forward voltage drop. You need to oversample the Arduino’s ADC to detect the few millivolt change reliably, but overall it’s pretty simple once you understand the principle.

But [Andrzej Laczewski], like many of our beloved readers, feels the Arduino and other microcontrollers can be a crutch if used exclusively. So he set out to replicate this hack with that most cherished of ICs, the 555 timer. In the video after the break, he demonstrates his “old-school” LED candle for anyone who thinks the only way to control an LED is with digitalWrite.

Not to say it’s easy to replicate the original Arduino project with a 555, or that it’s even practical. [Andrzej] simply wanted to show it was possible, which is something we always respect around these parts. He goes into great detail on how he developed and tested the circuit, even including oscilloscope screenshots showing how the different components work together in real-time. But the short version is that a MOSFET is used to turn the LED on and off, a comparator detects change in the LED’s voltage drop, and the 555 is used to control how long the LED stays off for.

Ever the traditionalist, [Andrzej] wrapped up this build by etching his own PCB using a variation of the classic laser toner transfer method. If this all looks a bit too much like Black Magic to you, there’s no shame in sticking with the Arduino version. At 1/20th of the parts count, and with no calibration required, who’s to say which version is “simpler”.

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Making An Arduino Shield PCB With Fritzing

November 26, 2017 by 15 Comments

[Allan Schwartz] decided to document his experience using Fritzing to design, fabricate, and test a custom Arduino shield PCB, and his step-by-step documentation makes the workflow very clear. Anyone who is curious or has been looking for an opportunity to get started will find [Allan]’s process useful to follow. The PCB in question has two shift registers, eight LEDs, eight buttons, and fits onto an Arduino; it’s just complex enough to demonstrate useful design features and methods while remaining accessible.

[Allan] starts with a basic breadboard design, draws a schematic, prototypes the circuit, then designs the PCB and orders it online, followed by assembly and testing. [Allan] had previously taught himself to use Eagle and etched his own PCBs via the toner transfer method, but decided to use Fritzing instead this time around and found it helpful and easy to use.

About a year ago we saw Fritzing put through its paces for PCB design, and at the time found that it didn’t impress much from an engineering perspective. Regardless, as a hobbyist [Allan] found real value in using Fritzing for his project from beginning to end; he documented both the process and his observations in order to help others, and that’s wonderful.

Wearable Foxhunt Transmitter For Conventions

August 31, 2017 by 13 Comments

Amateur radio operator [KE4FOX] wanted to build his own 2M fox hunt transmitter for use at conventions. It would be contained in a 1020 Pelican micro case and attached to a person who would walk around transmitting a signal, leaving the hams to track down the fox. The project uses a DRA818 VHF/UHF transceiver plugged into a low-pass filter combined with a hardware DTMF decoder, all controlled by an ATmega328P and powered by a 11.2 mAh battery.

[KE4FOX] also etched his own PCB, using the PCB toner transfer method, folding a sheet of transfer paper around the board to align both layers. Then he etched the board using cupric chloride. When assembling the board he realized he had made a terrible error, assuming the transceiver module’s pins went in the top layer when in fact they should have gone in the bottom layer. He solved this by soldering in the module in upside down.

He dropped the project into the 1020 and installed an SMA antenna. After he assembled the project he found out that the level shifter he used on the Arduino’s 5 V data didn’t work as expected and it was stuck at a single frequency. Something to work on for V2!

We publish a large number of amateur radio posts here on Hackaday, including fox hunting with Raspberry Pi and how to make a TDOA directional antenna.

[thanks, that Kat!]

Hackaday Prize Entry: PCBs On Demand With Etchr

July 11, 2017 by 44 Comments

The ambitious etchr – the PCB Printer is just a concept at the moment, but it’s not often we see someone trying to tackle desktop PCB production in a new way. Creator [Jonathan Beri] is keenly aware that when it comes to creating electronics, the bottleneck for most workflows is the PCB itself. Services like OSH Park make professionally fabricated PCBs accessible at a low cost, but part of the bargain is that turnaround times are often measured in weeks.

[Jonathan]’s concept for etchr is a small system that automates not only etching a copper-clad board with all the attendant flooding and draining of chemicals, but applying a solder mask and silkscreen layer labeling as well. The only thing left to do would be to drill any required holes.

The idea behind etchr is to first take a copper-clad board with photoresistive film or spray applied to it, and fix it into a frame. A UV projector takes care of putting the traces pattern onto the board (and also handles a UV-curable solder mask in a later step) and the deep frame doubles as a receptacle for any chemical treatments such as the etching and cleaning. It’s an ambitious project, but the processes behind each step are well-understood and bringing them all together in a single machine is an intriguing approach.

Desktop production of PCBs can be done in a few ways, including etching via the toner transfer method (whose results our own Elliot Williams clearly explained how to take from good to great). An alternative is to mill the PCBs out directly, a job a tool like the Othermill is designed specifically to do. It’s interesting to see an approach that includes applying a solder mask.

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From Zero To Nano

February 22, 2017 by 20 Comments

Have you ever wanted to build your own Arduino from scratch? [Pratik Makwana] shares the entire process of designing, building and flashing an Arduino Nano clone. This is not an entry-level project and requires some knowledge of soldering to succeed with such small components, but it is highly rewarding to make. Although it’s a cheap build, it’s probably cheaper to just buy a Nano. That’s not the point.

The goal here and the interesting part of the project is that you can follow the entire process of making the board. You can use the knowledge to design your own board, your own variant or even a completely different project.

from-zero-to-nano-thumb[Pratik Makwana] starts by showing how to design the circuit schematic diagram in an EDA tool (Eagle) and the corresponding PCB layout design. He then uses the toner transfer method and a laminator to imprint the circuit into the copper board for later etching and drilling. The challenging soldering process is not detailed, if you need some help soldering SMD sized components we covered some different processes before, from a toaster oven to a drag soldering process with Kapton tape.

Last but not least, the bootloader firmware. This was done using an Arduino UNO working as master and the newly created the Arduino Nano clone as target. After that you’re set to go. To run an actual sketch, just use your standard USB to UART converter to burn it and proceed as usual.

Voilá, from zero to Nano:

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