New Part Day: ATtiny102 And 104

August 1, 2016 by Elliot Williams 89 Comments

Atmel put out some new, small microcontroller chips early this year, and we’re just now starting to think about how we’d use them. The ATtiny102 and ATtiny104 (datasheet) sell for about a buck (US) and come in manageable SOIC packages with eight and fourteen pins respectively. It’s a strange chip though, with capabilities that fit somewhere between the grain-of-rice-sized ATtiny10 and the hacker-staple ATtiny25-45-85 series.

The ATtiny104 has a bunch of pins for not much money. It’s got a real hardware USART, which none of the other low-end AVRs do, and it’s capable of SPI in master mode. It has only one counter, but it’s a 16-bit counter, and it’s got the full AVR 10-bit ADC instead of the ATtiny10’s limited 8-bit ADC. The biggest limitation, that it shares with the ATtiny10, is that it has only 1 KB of program flash memory and 32 bytes (!) of RAM. You’re probably going to want to program this beast in assembler.

Read on for more reviews, and check out [kodera2t]’s video review at the end.

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Hackaday Links: July 31, 2016

July 31, 2016 by Brian Benchoff 14 Comments

Going to DEF CON this week? Getting into Vegas early? We’re having a meetup on Wednesday, in the middle of the day, in the desert. It’s all going down at the grave of James T. Kirk. Rumor has it, the Metrons will abduct a few of us and make us fight to the death on a planet with impossible geology.

The Hara Arena is closing down. The Hara Arena in Dayton, Ohio is the home of Hamvention, the largest gathering of amateur radio enthusiasts in the US. I was there last May, and I can assure you, the Hara Arena has fallen into a state of disrepair. The ARRL reports hamvention will be at a new venue next year. The last scheduled event, after which there will be an auction for venue equipment and furniture, will be on August 27th. It’ll be a comic book and toy show.

Hackaday.io has a log of projects. Some might say it has too many projects. The search is great, but sometimes you just want to look at a random project. That’s the problem [Greg] solved with his Hackaday.io randomizer. It returns a random Hackaday.io project, allowing you to gawk at all the boards and resistors found within.

Primitive Technology is a YouTube channel you should watch. It’s a guy (who doesn’t talk), building everything starting with pre-stone age technology. He built a house with a heated floor, somewhat decent pottery, and this week he entered the iron age. The latest video shows him building a squirrel cage fan out of clay and bark to smelt iron. The ore was actually iron-bearing bacteria, mixed with charcoal and wood ash, and placed into a crude but accurate smelting furnace. The end result is a few bb-sized grains of iron and a lot of melted flux. That’s not much, and is certainly not an accurate portrayal of what was being done 5,000 years ago, but it does mean the Internet’s favorite guy in the woods has entered the iron age while completely skipping over bronze.

Freeside Atlanta says they’re the largest hackerspace on the east coast, and to show off all the cool goings on, they made a walk through video.

Hackaday has a retro edition. It’s a wide selection of Hackaday posts presented in a format without JavaScript, CSS, ads, or any other Web 2.0 cruft. There’s an open challenge for anyone to load the retro site with a 4004 CPU. I know it can be done, but no one has presented evidence of doing it. [Lukas] just sent in his retro submission with a Z80 single board computer displaying some of the page on seven-segment displays. It’s basically a terminal emulator connected to a laptop that does most of the work, but this is the most minimal retro submission we’ve ever received.

Hacklet 118 – Infrared And Universal Remote Controls

July 30, 2016 by Adam Fabio 21 Comments

The first remote control for a TV was the Zenith Space Command back in the 1950’s. Space Command used sounds at ultrasonic frequencies to control the set. It wasn’t until the 1980’s and the Viewstar cable box that infrared entered the picture. Remote controls spread like wildfire. It wasn’t long before every piece of consumer electronics had one. Coffee tables were littered with the devices. It didn’t take long for universal remotes to hit the scene. [Woz] himself worked on the CL9 Core device, back in 1987. Even in today’s world of smart TV’s and the internet of things, universal remotes are still a big item. Hackers, makers, and engineers are always trying to build a device that works better for them. This week’s Hacklet is about some of the best universal and IR remote projects on Hackaday.io!

We start with [Harikrishna] and zmote. Zmote is an open source WiFi enabled, infrared, 360° remote control. That’s a mouthful. It might be easier to say it’s an ESP8266 and some IR LEDs. An ESP-01 module connects the device to WiFi and provides the 32-bit processor which runs the show. Learning functionality comes courtesy of a TSOP1738 modulated infrared receiver. The beauty of the Zmote is in the software. REST and MQTT connectivity are available. Everything is MIT licensed, and all the code is available on Github.

Next up is [Benjamin Kenobi] with TV Remote Control, Limited. Not everyone can operate the tiny buttons on a modern remote. [Benjamin] built this device for Easton, a special kid with a disability that impairs his motor skills. The 3D printed case holds two buttons – one for power, and one to change the channel. An Arduino Nano running [Ken Shirriff’s] IR library is the brains of the operation. The IR signal timing is hard coded for simplicity. One problem [Ben] ran into was the Nano’s high current draw, even in sleep mode. Batteries wouldn’t last a week. A simple diode circuit with a reed relay keeps the Nano shut down until Easton presses a button.

Next we have [Nevyn] with OpenIR – Infrared Remote Control. A dead DSLR remote shutter release was all the motivation [Nevyn] needed to start work on his own universal remote control. OpenIR can be connected to (and controlled by) just about anything with a UART – a PC via an FTDI cable, a Bluetooth module, even an ESP8266. The module can be programmed by entering pulse length data through a custom Windows application. The Windows app even allows the user to view the pulses graphically, like a scope. The data is stored on an EEPROM on OpenIR’s PCB. Once programmed, the OpenIR board is ready to control the world.

Finally, we have [facelessloser] with One button TV remote. This project may be the simplest open source remote control this side of TV-B-GONE. He wanted to build a simple remote control for his young daughter to scan between the various kids channels. A simple toggle switch turns the device on, and one button performs the rest of the magic. [Facelessloser] wanted to “move up” from an Arduino to an ATtiny85. This project became part of his ATtiny education. A custom PCB from OSH Park ties things together. A simple black project box keeps the electronics safe from tiny fingers – at least until she’s old enough to use a screwdriver.

If you want to see more IR and universal remote��projects, check out our new infrared and universal remote projects list. See a project I might have missed? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Fail Of The Week: Magnetic Flow Measurement Gone Wrong

July 29, 2016 by Dan Maloney 42 Comments

Physics gives us the basic tools needed to understand the universe, but turning theory into something useful is how engineers make their living. Pushing on that boundary is the subject of this week’s Fail of the Week, wherein we follow the travails of making a working magnetic flowmeter (YouTube, embedded below).

Theory suggests that measuring fluid flow should be simple. After all, sticking a magnetic paddle wheel into a fluid stream and counting pulses with a reed switch or Hall sensor is pretty straightforward, right? In this case, though, [Grady] of Practical Engineering starts out with a much more complicated flow measurement modality – electromagnetic detection. He does a great job of explaining Faraday’s Law of Induction and how a fluid can be the conductor that moves through a magnetic field and has a measurable current induced in it. The current should be proportional to the velocity of the fluid, so it should be a snap to whip up a homebrew magnetic flowmeter, right? Nope – despite valiant effort, [Grady] was never able to get a usable signal out of the noise in his system.

The theory is sound, his test rig looks workable, and he’s got some pretty decent instrumentation. So where did [Grady] go wrong? Could he clean up the signal with a better instrumentation amp? What would happen if he changed the process fluid to something more conductive, like salt water? By his own admission, electrical engineering is not his strong suit – he’s a civil engineer by trade. Think you can clean up that signal? Let us know in the comments section.

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Books You Should Read: The Annotated Build-It-Yourself Science Laboratory

July 29, 2016 by Al Williams 33 Comments

Like a lot of engineers, I spent a lot of time in libraries when I was a kid. There were certain books you’d check out over and over again. One of those was [Raymond Barrett’s] Build-It-Yourself Science Laboratory. That book really captured my imagination with plans for things as simple as a funnel to as complex as an arc furnace (I actually built that one; see diagram above), a cloud chamber, and an analog computer (see below). That book was from 1963 and that did present a few unique challenges when I read it in the 1970’s. It presents even more difficulty if you try to reproduce some of the projects in it today.

The world of 1963 was not as safe as our world today. Kids rode bicycles with no protective gear. Dentists gave kids mercury to play with. You could eat a little paint or have asbestos in your ceiling, and no one really worried about it.

That means some of the gear and experiments Barrett covers are difficult to recreate today or are just plain dangerous. For example, he suggests getting sulphuric acid at the drugstore. I don’t suggest you call your local Walgreens and ask them for it. The arc furnace — which could melt a nail, as I found out first hand — used a salt water rheostat which was basically an AC power cord with one conductor cut and passed through and open glass jar containing salt water! Fishing sinkers kept the wire from moving about (you hoped) and I suppose the chlorine gas probably emitted didn’t do me any permanent harm.

I was delighted to see that [Windell Oskay] has revised and rebuilt this great old book into a new edition. As much of the original as possible is still present, but with notes about how to work around material you can’t get any more or notes about safety.

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Ask Hackaday: Is The ESP8266 5V Tolerant?

July 28, 2016 by Brian Benchoff 130 Comments

The ESP8266 is the reigning WiFi wonderchip, quickly securing its reputation as the go-to platform for an entire ecosystem of wireless devices. There’s nothing that beats the ESP8266 on a capability vs. price comparison, and this tiny chip is even finding its way into commercial products. It’s also a fantastic device for the hardware tinkerer, leading to thousands of homebrew projects revolving around this tiny magical device.

In every technical document, summary, and description of the ESP8266, the ESP8266 is said to be a 3.3V part. While we’re well into the age of 3.3V logic, there are still an incredible number of boards and hardware that still operate using 5V logic. Over on the Hackaday.io stack, [Radomir] is questioning this basic assumption. He’s wondering if the ESP8266 is 5V tolerant after all. If it is, great. We don’t need level converters, and interfacing the ESP to USB TTL serial adapters becomes much easier. Yes, you’ll still need to use a regulator if the rest of your project is running at 5V, but if the pins are 5V tolerant, interfacing the ESP8266 with a variety of hardware becomes very easy.

[Radomir]’s evidence for the possibility of 5V tolerant inputs comes from a slight difference in the official datasheet from Espressif, and the datasheet translated by the community before Espressif realized how many of these chips they were going to sell.

The best evidence of 5V tolerant pins might come from real-world experience — if you can drive a pin with 5V for months on end without it failing, there might be something to this claim. It’s not definitive, though; just because a device will work with 5V input pins for a few months doesn’t mean it won’t fail in the future. So far a few people have spoken up and presented ESPs directly connected to the 5V pin of an Arduino that still work after months of service. If this is evidence of 5V tolerant design or simply luck is another matter entirely.

While the official datasheet from Espressif lists a maximum V_IH of 3.3V, maximum specs rarely are true maximums — you can always push a part harder without things flying apart at the seams. Unfortunately, unless we hear something from the engineers at Espressif, we won’t know if the ESP8266 was designed to be 5V tolerant, if it can handle 5V signals reliably, or if 5V signals are a really good way to kill a chip eventually.

Lucky for us — and this brings us to the entire point of an Ask Hackaday column — a few Espressif engineers read Hackaday. They’re welcome to pseudonymously chime in below along with the rest of the peanut gallery. Failing that, the ESP8266 has been decapped; are there any die inspection wizards who can back up a claim of 5V tolerance for the GPIO? We’d also be interested in hearing any ideas for stress testing pin tolerance.

3D Printering: Non-Planar Layer FDM

July 27, 2016 by Moritz Walter 40 Comments

Non-planar layer Fused Deposition Modeling (FDM) is any form of fused deposition modeling where the 3D printed layers aren’t flat or of uniform thickness. For example, if you’re using mesh bed leveling on your 3D printer, you are already using non-planar layer FDM. But why stop at compensating for curved build plates? Non-planar layer FDM has more applications and there are quite a few projects out there exploring the possibilities. In this article, we are going to have a look at what the trick yields for us.

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