555

Fighting Machine Tool Chatter with a 555 Timer

October 6, 2017 by 32 Comments

Vibration is a fact of life in almost every machining operation. Whether you’re milling, drilling, turning, or grinding, vibration can result in chatter that can ruin a part. Fighting chatter has generally been a matter of adding more mass to the machine, but if you’re clever about things, chatter reduction can be accomplished electronically, too. (YouTube, embedded below.)

When you know a little something about resonance, machine vibration and chatter start to make sense. [AvE] spends quite a bit of time explaining and demonstrating resonance in the video — fair warning about his usual salty shop language. His goal with the demo is to show that chatter comes from continued excitation of a flexible beam, which in this case is a piece of stock in the lathe chuck with no tailstock support. The idea is that by rapidly varying the speed of the lathe slightly, the system never spends very long at the resonant frequency. His method relies on a variable-frequency drive (VFD) with programmable IO pins. A simple 555 timer board drives a relay to toggle the IO pins on and off, cycling the VFD up and down by a couple of hertz. The resulting 100 RPM change in spindle speed as the timer cycles reduces the amount of time spent at the resonant frequency. The results don’t look too bad — not perfect, but a definite improvement.

It’s an interesting technique to keep in mind, and a big step up from the usual technique of more mass.

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The Art of Blinky Business Cards

October 4, 2017 by 34 Comments

Business cards are stuck somewhere between antiquity and convenience. On one hand, we have very convenient paperless solutions for contact swapping including Bluetooth, NFC, and just saying, “Hey, put your number into my phone, please.” On the other hand, holding something from another person is a more personal and memorable exchange. I would liken this to the difference between an eBook and a paperback. One is supremely convenient while the other is tactile. There’s a reason business cards have survived longer than the Rolodex.

Protocols and culture surrounding the exchange of cards are meant to make yourself memorable and a card which is easy to associate with you can work long after you’ve given your card away. This may seem moot if you are assigned cards when you start a new job, but personal business cards are invaluable for meeting people outside of work and you are the one to decide how wild or creative to make them.

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This Synth Is Okay

October 3, 2017 by 18 Comments

While this 3D printed synthesizer might just be okay, we’re going to say it’s better than that. Why? [oskitone] did something with a 555 timer.

The Okay synth from [oskitone] uses a completely 3D printed enclosure. Even the keys are printed. Underneath these keys is a small PCB loaded up with tact switches and small potentiometers. This board runs to another board loaded up with a 555 timer and a CD4040 frequency divider. This, in turn, goes into an LM386 amplifier. It’s more or less the simplest synth you can make.

If this synth looks familiar, you’re right. A few months ago, [oskitone] released the Hello F0 synth, a simple wooden box with 3D printed keys, a few switches, and a single 4046 PLL oscillator. It’s the simplest synth you can build, but it is something that can be extended into a real, proper synthesizer with different waveforms, LFOs, and envelope generators.

The sound of this chip is a very hard square wave with none of the subtleties of A,S,D, or R. Turn down the octave knob and it makes a great bass synth, or turn the octave knob to the middle for some great chiptune tones. All the 3D models for this synth are available on Thingiverse, so if you’d like to print your own, have at it.

You can check out the demo of the Okay synth below.

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Someone Finally Did It With A 555

August 22, 2017 by 73 Comments

[Jarunzel] needed a device that would automatically click the left button on a mouse at a pre-set interval. For regular Hackaday readers, this is an easy challenge. You could do it with an ATtiny85 using the VUSB library, a few resistors and diodes, and a bit of code that emulates a USB device that constantly sends mouse clicks over USB every few seconds. You could also do it with a Raspberry Pi Zero, using the USB gadget protocol. Now, this mouse-clicking gadget would be connected to the Internet (!), programmable with Node or whatever the kids are using these days, and would have some major blog cred. If you’re feeling adventurous, this mouse clicker gadget could be built with an STM32, Cypress PSoC, or whatever microcontroller you have in your magical bag of hacker tricks.

Then again, you could also do it with a 555 timer.

The reason [Jarunzel] couldn’t use any of the fancy hackertools for this build is because the system wouldn’t accept two mouse devices. No matter, because Maplin has a neat kit with a 555 timer and a relay. The relay is wired up across the microswitch in the mouse, and setting the values correctly makes the mouse click about once per second, with a click duration of about 100ms. Good enough.

With the kit built, wired into the mouse, a small app built to test the device, and a nice project box constructed, [Jarunzel] had exactly what he needed. There’s even a video of this mouse clicker in action. You can check out that riveting footage below.

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You Know You Can Do That with a 555

August 10, 2017 by 34 Comments

Hardly a week goes by that we don’t post a project where at least one commenter will lament that the hacker could have just used a 555. [Peter Monta] clearly gets that point of view. For a 555 design contest, he created both digital logic gates and an op amp, all using 555 chips. We can’t quite imagine the post apocalyptic world where the only surviving electronic components are 555 chips, but if that day were to come, [Peter] is your guy.

Using the internal structure of the 555, [Peter] formed a basic logic gate, an inverter, latches, and more. He also composed things like counters and seven-segment decoders. He had a very simple 4-bit CPU design in Verilog that he was going to attempt until he realized it would map into almost 400 chips (half of that if you’d use a dual 555, but still). If you built this successfully, we would probably post it, by the way.  You can see a video of the digital logic counter, below.

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Quick Hack Cleans Data from Sump Pump

July 28, 2017 by 11 Comments

Nobody likes to monitor things as much as a hacker, even mundane things like sump pumps. And hackers love clean data too, so when [Felix]’s sump pump water level data was made useless by a new pump controller, he just knew he had to hack the controller to clean up his data.

Monitoring a sump pump might seem extreme, but as a system that often protects against catastrophic damage, the responsible homeowner strives to take care of it. [Felix] goes a bit further than the average homeowner, though, with an ultrasonic sensor to continually measure the water level in the sump and alert him to pending catastrophes. Being a belt and suspenders kind of guy, he also added a float switch to control the pump, but found that the rapid cycle time made his measurements useless. Luckily the unit used a 555 timer to control the pump’s run time after triggering, so a simple calculation of the right RC values and a little solder job let him increase the on time of the pump. The result: a dry basement and clean data.

We recently discussed the evolution of home automation if you want to know more about the systems that sensors and actuators like these can be part of. Or for a more nuts and bolts guide to networking things together, our primer on MQTT might help.

Push Button, Receive Beverage!

July 21, 2017 by 9 Comments

Here’s a rec-room ready hack: an automatic drink dispenser.

[truebassB]’s dispenser operates around a 555 timer, adjusted by a potentiometer. Push a button and a cup pours in a few seconds, or hold the other button to dispense as much as you want.

The dispenser is made from MDF and particle board glued together, with some LEDs and paper prints to spruce it up. Just don’t forget a small spill sink for any miscalculated pours. You needn’t fret over the internals either, as the parts are easily acquired: a pair of momentary switches, a 12V micro air pump, a brass nozzle, food-safe pvc tube,  a custom 555 timing circuit — otherwise readily available online — a toggle switch, a power supply plug plus adapter and a 12V battery.

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