ESP32 Alarm Clock Doesn’t Skimp On The Features

April 11, 2019 by 11 Comments

The ESP family of microcontrollers is absolutely on fire right now, with a decent chunk of the projects that come our way now based on one of the impossibly cheap WiFi-enabled boards. In fact, they are so cheap and popular that we’ve started to see a somewhat unexpected trend; people have a tendency to use them as drop-in replacements, despite the more modern boards being considerably more powerful than required. The end result is a bunch of projects in which the ESP is simply underutilized. It’s not a big deal, but somewhat disappointing to see.

But we can assure you this ESP32 alarm clock created by [Pangodream] is absolutely not one of them. He’s packed an impressive number of features into this unassuming little timepiece, and it’s really an excellent example of how much these boards are capable of without breaking a sweat. From DIY touch sensors to the Android application used to configure the clock over the network, this project is overflowing with neat hardware and software tricks worth taking a closer look at.

Inside the 3D printed case, the clock features a BH150 light sensor, the very popular DHT-11 for detecting temperature and humidity, as well as a ILI9341 2.8 inch LCD for the display. In a particularly clever touch (get it?), [Pangodream] used three coins connected to the digital pins of the ESP32 as capacitive sensors. These allow him to interact with the click just by tapping the top of the case, and saved him the trouble of adding traditional switches or buttons. We might have put some indentations in the top case to make identifying which of the three “buttons” you’re pushing, but we suppose the invisible interface does make things look a little more futuristic.

But if even that is too much physical touching for you, then [Pangodream] has come up with a fairly robust system for controlling and interacting with the clock over the network. It’s not just a convenient way of setting the time, a good number of the clock’s functions can be polled and configured in this manner; everything from the sensitivity of the touch sensors to how many times it will beep when the alarm goes off. To make things easier, he’s even wrapped it all up in a handy Android application for on the go configuration.

If this clock doesn’t offer you the level of over-engineering you require, check out this build that uses no less than five ESP32s to get the job done. Or maybe this one that hooks into NASA’s Deep Space Network.

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This Bike Pump Now Sucks

April 11, 2019 by 18 Comments

Pulling a vacuum is something every proud maker must do once in a while. Whether you’re degassing epoxy or vacuum forming parts, you’ll need a reliable pump to get the job done. [drcrash] has just the guide to help – on how to convert a regular handpump to vacuum duty. (Video embedded after the break.)

[drcrash] recommends starting with a Slime brand 2060-A pump or similar. It’s a basic hand pump, with no pressure gauges or other frills to get in the way. It’s also got a strong steel shaft that can hold up to repeated use. You’ll also need some tubing and a check valve to get the job done.

The basic concept is to reconfigure the pump to suck air out of things rather than blowing it into them. By removing the original check valve and installing one in the opposite direction, and reversing the pump’s piston, it’s possible to pull good vacuum without breaking a sweat. [drcrash] reports that it’s possible to go up to 11 psi below atmospheric with this setup, which is plenty for a wide range of applications. If you need to go further, you can try building your own turbomolecular pump instead.

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The $50 Ham: Checking Out The Local Repeater Scene

April 11, 2019 by 24 Comments

So far in this series, we’ve covered the absolute basics of getting on the air as a radio amateur – getting licensed, and getting a transceiver. Both have been very low-cost exercises, at least in terms of wallet impact. Passing the test is only a matter of spending the time to study and perhaps shelling out a nominal fee, and a handy-talkie transceiver for the 2-meter and 70-centimeter ham bands can be had for well under $50. If you’re playing along at home, you haven’t really invested much yet.

The total won’t go up much this week, if at all. This time we’re going to talk about what to actually do with your new privileges. The first step for most Technician-class amateur radio operators is checking out the local repeaters, most of which are set up exactly for the bands that Techs have access to. We’ll cover what exactly repeaters are, what they’re used for, and how to go about keying up for the first time to talk to your fellow hams.

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Implementing Qi Inductive Charging Yourself

April 11, 2019 by 21 Comments

Inductive charging is a technology that has promised a lot, but hasn’t quite delivered on the promise of never needing to plug in your phone again. The technology behind it is surprisingly simple though, and [Vinod.S] takes us through it all with an ATtiny13-based example.

An inductive charger has to be clever in its operation, for if it were to operate continuously it would soon have more in common with an inductive hob and thus become a fire risk, so it has to be sure that a compatible device is resting upon it before it tries to transmit power. It achieves this by periodically sending out a pulse of power intended to wake any devices in contact with it, and the device responds with a serial data stream encoded onto the device’s field by modifying the resonance of the receiver tuned circuit. This is done by a pair of MOSFETs under the control of the ATtiny in [Vinod]’s device, resulting in a functioning inductive power receiver built on a piece of prototyping board and sporting a buck converter capable of supplying 5 volts suitable to charge a phone. You can find the code on GitHub and see it in action below the break.

This tech has made an appearance here before a few times, such as when a Qi charger was integrated into a Chromebook.

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Flip Chips And Sunken Ships: Packaging Trick For Faster, Smaller Semiconductors

April 11, 2019 by 20 Comments

You may have heard the phrase “flip-chip” before: it’s a broad term referring to several integrated circuit packaging methods, the common thread being that the semiconductor die is flipped upside down so the active surface is closest to the PCB. As opposed to the more traditional method in which the IC is face-up and connected to the packaging with bond wires, this allows for ultimate packaging efficiency and impressive performance gains. We hear a lot about advances in the integrated circuits themselves, but the packages that carry them and the issues they solve — and sometimes create — get less exposure.

Cutaway view of traditional wire-bond BGA package. Image CC-BY-SA 4.0 @TubeTimeUS

Let’s have a look at why semiconductor manufacturers decided to turn things on their head, and see how radioactive solder and ancient Roman shipwrecks fit in.

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A Bolt-On I2C Navigation Key For Your Next Project

April 11, 2019 by 10 Comments

We often talk about the advantages of modular hardware here at Hackaday; the ability to just order a few parts online, hook them up with some jumper wires, and move onto the software side of things is a monumental time saver when it comes to prototyping. So anytime we see a new module that’s going to save us time and aggravation down the road, we get a bit excited.

Today we present the very slick I2CNavKey developed by [Saimon], a turn-key interface solution for your builds that can’t quite get away with a couple toggle switches. It not only gives you a four-way directional pad with center button, but a rotary “wheel” like on the old iPods. All of which you can access easily and with a minimum of wiring thanks to the wonders of I2C.

But even that might be selling the module short. This isn’t just a couple of buttons on a breakout board, the I2CNavKey is powered by its own PIC16F18345 microcontroller and features three configurable GPIOs with PWM support (perfect for an RGB LED) plus 256 bytes of onboard EEPROM storage.

[Saimon] has released the entire project as open source hardware for your hacking pleasure, but you can also get them as ready-to-use modules on Tindie for $18 USD [Editor’s Note: Because of a typo we originally we left the 1 out of the price]. Whether you’re a paying customer or not, you get access to the project’s absolutely phenomenal documentation, including a nearly 30 page manual that contains everything you’d ever want to know about the I2CNavKey and how to integrate it into your project. If all hardware was documented with this level of dedication, the world would be a much nicer place for folks like us.

If you recognize the name, or perhaps the affinity for neat I2C-connected input devices, it’s probably because you’ve seen his very similar I2C rotary encoder on these pages previously, which was a finalist in our Open Hardware Design Challenge during the 2018 Hackaday Prize.

An Even Smaller World’s Smallest LED Blinky

April 11, 2019 by 14 Comments

Everything can be done with a 555. It’s a universal law, as all readers know. And a flashing light, you might think, will have been done before many times. But nobody has ever created a 555 flashing light as small as thie one created by [TWires], who has taken a TI LMC555 chip-scale packaged 555 and dead-bugged a working flasher on its surface using 01005 discrete components. There is a video showing it in operation that we’ve placed below the break, and it’s tiny. We probably all consider ourselves to be quite good at soldering, but this piece of work is in another class entirely.

The project was inspired by [Mike Harrison]’s previous holder of the smallest blinky prize, which used a PIC microcontroller atop a tiny surface mount supercapacitor. It uses the same capacitor for power, but we’d say it’s taken the blinky to new levels of tininess. Does this mean a new arms race is upon us in the world of tiny blinkies? We hope so, and though it’s difficult to imagine they can get much smaller we can’t wait to see what people come up with. If there’s one thing about our community it’s that saying something can’t be done is unwise: one of you will find a way if it is at all possible. Even Microchip’s MIC1555 might be a bit big though, so something inventive is called for.

For a fascinating run-down of the state of the 555 art, read this article from our own [Ted Yapo].

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