Hacklet #4 — PCB Tools and Wristwatches

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The Hackaday Prize is heating up! When we set up the prize, we expected to see some incredible entries, and you guys haven’t let us down. Projects like SatNOGS, which aims to create a global network of satellite ground stations, or OpenMV, a low-cost Python powered vision module, are seriously blowing us away.

We’re starting to give away some prizes through community voting and there’s still plenty of time for you to enter. Check out The Hackaday Prize page for the full details.

Low Cost Printed Circuit Board Tools

Pick and Place

We’ve seen mills, lathes, CNC machines and 3D printers, but if there is any device that gets a hardware hacker’s attention, it’s a pick and place machine. In the PCB industry these machines pick up thousands of parts every hour, perfectly placing them on printed circuit boards. The downside is they’re incredibly expensive. The cheapest Chinese machines without vision start in the $4000 USD price range.

[Neil] aims to break down those price barriers with a $300 Pick and Place Machine that doubles as a 3D printer. He’s using delta 3D printer hardware to do it, and he’s throwing in everything! OpenCV based vision, multiple tool heads, reel and tray pick up, [Neil] has covered all the major points. He can’t do it alone though, so he’s looking for help. Check it out, and give him a hand (or a skull)!
pcbMill

A low-cost pick and place machine will need printed circuit boards to work on. Not to worry, [shlonkin] has you covered with his PCB mill for under $10. Built from recycled printers, an Arduino, and host software written in processing, [shlonkin] has already posted impressive photos of boards his machine has milled. The main problem [shlonkin] has run into is longevity with plastic parts. In his most recent update, he’s looking for ideas. Can you help him?

Digital Watches

Anyone will tell you that digital watches are a pretty neat idea. With the era of smartwatches upon us, more than one hacker has delved into building their own timepiece. We’re happy to report that most of them even tell time.

walltech[Walltech] has gone all out to create the ultimate watch. His OLED Smart Watch 6.0 is the culmination of years of work. The watch features a 1.5” OLED display, an SD card slot, and a vibrator motor. It has Bluetooth 4.0 to connect to the world, and an Atmel ATmega32u4 as its brain. A 500mAh battery will power the watch for 18-24 hours per charge.

[Walltech] plans to make it do everything from SMS and email notifications to music streaming. Don’t see a feature you want? Add it! Smart Watch 6.0 Is completely open source, so you can hop into the code and hack away!

tilttouchtime2On the other side of the spectrum is [askoog89’s] Tilt Touch Time, which utilizes  those awesome bubble LED displays some of us remember from the 70’s. The retro look is only 3D printed skin deep though, as [askoog89] is using an ATtiny2313 processor. Atmel’s Qtouch is providing the capacitive touch sensing, while a tilt sensor helps Tilt Touch Time live up to its name. [Askoog89] has submitted his watch to The Hackaday Prize, so he’s trying to figure out a way to use the touch sensor to sync time with a PC. If that doesn’t work out, we bet those bubble LEDs would make great light sensors for some monitor-blink-sync action.

Fallout fans have seen plenty of PIP boys here on Hackaday, but have you seen [jara’s] PIP Watch? This Personal Information Panel is going big on size but low on power with a 3 inch e-ink display. [Jara] is using an STM32F101 ARM Cortex-M3 CPU, so he’s got plenty of processing power at his disposal. He’s connecting to the world through a Bluetooth serial link. All he needs is a Geiger counter, and he’s good to go!

pipWatch

That’s it for this week’s Hacklet, stay tuned for next week when we bring you more of what’s happening at Hackaday.io!

Simple transistor tester makes sorting easy

simple_transistor_sorter

Hacker [Dino Segovis] is back with yet another installment of his Hack a Week series, and it’s looking like he isn’t too worse for wear after hunkering down to face hurricane Irene.

This week, it seems that [Dino] is having some problems separating his PNP transistors from his NPNs. After Albert Einstein proves to be less than useful when it comes to sorting electronic components, [Dino] decided to build a simple transistor tester to help him tell his PNPs and NPNs apart without having to resort to looking up product data sheets.

The tester itself is relatively simple to build. As you can see in the video below, it consists of a power supply, an LED, a few resistors, a pair of known transistors, and not much else. When everything is hooked together, the NPN/PNP pair causes the LED to light up, but the circuit is broken whenever one of the transistors is removed. Inserting a new transistor into the empty spot on the breadboard immediately lets you know which sort of transistor you have inserted.

Sure you can tell transistors apart with a multimeter, but if you have a whole drawer full of loose components, this is a far more efficient option.

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A quick and dirty VU meter for your next party

If you want an easy project to spice up your next party, chances are you already have parts on hand to throw together [Mikerbot’s] quick and dirty VU-meter lights. The circuit he designed uses the audio input to trigger the base of a PNP transistor, toggling power through a string of LEDs. He’s using four lights for each of the stereo output signals, making them pulse with the music as seen in the video after the break. The circuit is built on a breadboard, and housed in a picture frame with a less-than-impressive diffuser (we think that’s always the hardest part… check out the Heavy Frost used in this project if you want something that works really well).

There are some VU meter chips out there that will really augment this concept. But one improvement might be to throw in an amplifier chip like the LM386 and a couple of potentiometers so that you can dial-in the sensitivity.

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2-bit full adder using just thirty six 555 timers

This 2-bit adder was a lot of work to build. It uses a total of thirty-six 555 timers and it does have the option of adding or subtracting numbers. It’s a rather unorthodox use of the part, depending more on the chip as an inverter and taking advantage of the fact that there’s an NPN transistor built into it. [cpu86] did use some PNP transistors to give him the ability to turn off some of the 555’s to get everything working correctly.

He explains the use of two’s complement in the subtracting feature but the process is just touched on very quickly. Luckily there’s a huge eagle schematic available with his project writeup so that you can follow along and really grasp how this thing works. We’ve generated a PNG and embedded it after the break for your convenience. You’ll find it just after the two videos of the device in action.

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Gutting an air freshener for the parts

[Doug Paradis] took a good look inside the Air Wick Freshmatic Compact i-Motion and then stole all the parts for other projects. We’ve looked at adding a manual spray button or making air fresheners Internet enabled before. Those models didn’t have parts that were all that interesting, but this one has a passive infrared motion sensor. You’ll also gain three switches, a PNP transistor, and an LED.

Price seems to be all over the map for this model, but [Doug] says you can find it for $8 or less. After showing how to make a tool to bypass the triangular security screws, he explains how to access the PIR sensor. But if you want to be all you can be with the hardware, he details the modifications needed to patch into the analog and digital circuitry on the rest of the board too.

Replacing the driver board in an old-school door chime

[Dan Kouba’s] parents replaced their doorbell button with one that lights up and found that the chime wouldn’t stop sounding after the button was pushed. These lighted buttons use an incandescent bulb in parallel with the button (a piece of hardware we’ve hacked in the past). It draws a small amount of current which isn’t enough to trigger the chime, but it is just enough that the chime unit reacts as if the button press never stopped. His parents asked what he could do about this and after some investigation he build a replacement board for the chime unit based around an ATtiny26L. The board monitors the voltage drop across a resistor in the doorbell circuit. When the comparator on the AVR detects a rise in the voltage drop across the resistor it rings the chimes, actuating the solenoids with a set of PNP transistors. [Dan] sent us all of the details which you can check out after the break.

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