Down The Rabbit Hole Of STM32 Clock Options

November 23, 2014 by 14 Comments

Once you venture beyond the tame, comfortable walls of the 8-bit microcontroller world it can feel like you’re stuck in the jungle with a lot of unknown and oft scary hazards jut waiting to pounce. But the truth is that your horizons have expanded exponentially with the acceptable trade-off of increased complexity. That’s a pretty nice problem to have; the limitation becomes how much can you learn.

Here’s a great chance to expand your knowledge of the STM32 by learning more about the system clock options available. We’ve been working with STM32 chips for a few years now and still managed to find some interesting tidbits — like the fact that the High Speed External clock source accepts not just square waves but sine and triangle waves as well, and an interesting ‘gotcha’ about avoiding accidental overclocking. [Shawon M. Shahryiar] even covers one of our favorite subjects: watchdog timers (of which there are two different varieties on this chip). Even if this is not your go-to 32-bit chip family, most chips have similar clock source features so this reading will help give you a foothold when reading other datasheets.

There is a clock diagram at the top of that post which is small enough to be unreadable. You can get a better look at the diagram on page 12 of this datasheet. Oh, and just to save you the hassle of commenting on it, the chip shown above is not an f103… but it just happened to be sitting on our desk when we started writing.

IcosaLEDron: A 20-Sided Light Up Ball

November 23, 2014 by 5 Comments

Tired of balls that are just balls, and not glowing geometric constructions of electronics and wonderment? Get yourself an IcosaLEDron, the latest in Platonic solids loaded up with RGB LEDs.

The folks at Afrit Labs wanted a fun, glowy device that would show off the capabilities of IMUs and MEMS accelerometers. They came up with a ball with a circuit board inside and twenty WS2812B RGB LEDs studded around its circumference

The frame of the ball is simply a set of twenty tessellated triangles that can be folded up during assembly. The outer shell of the ball is again printed in one piece, but fabricated out of transparent NinjaFlex, an extraordinarily odd, squishy, and likely indestructible material.

Inside the IcosaLEDron is a PCB loaded up with an ATMega328p, an accelerometer, a LiPo battery charger, and quite a bit of wiring. Once the ball is assembled and locked down, the squishy outer exterior is installed and turned into a throwable plaything.

If 20 sides and 20 LEDs aren’t enough, how about a an astonishing 386-LED ball that’s animated and knows its orientation? That’s a project from Null Space Labs, and looking at it in person is hypnotic.

via Makezine

Using The ESP8266 As A Web-enabled Sensor

November 23, 2014 by 34 Comments

A few months ago, the ESP8266 came onto the scene as a cheap way to add WiFi to just about any project that had a spare UART. Since then, a few people have figured out how to get this neat chip running custom firmware, opening the doors to an Internet of Things based around an ESP8266. [Marc] and [Xavi] just wrote up a quick tutorial on how to turn the ESP8266 into a WiFi sensor platform that will relay the state of a GPIO pin to the Internet.

If you’re going to replicate this project, you won’t be using the stock firmware on the ESP. Instead of the stock firmware, [Marc] and [Xavi] are using the Lua-based firmware that allows for access to a few GPIOs on the device and scripting support to make application development easy. To upload this firmware to the ESP, [Marc] and [Xavi] needed a standard FTDI USB to serial converter, a few AT commands through a terminal program, and a few bits of wire.

The circuit [Marc] and [Xavi] ended up demoing for this tutorial is a simple webpage that’s updated every time a button is pressed. This will be installed in the door of their hackerspace in Barcelona, but already they have a great example of the ESP8266 in use.

Cosplaying As HAL 9000

November 23, 2014 by 11 Comments

2001: A Space Odyssey is one of the greatest films of all time, but unlike every other masterpiece of SciFi, you’re not going find many people cosplaying as characters from the movie. Going as a monolith to a con would be hilarious, but [jacqueslelezard] had an even better idea in mind: a HAL 9000 costume.

The costume itself is just bits of painted cardboard, shiny material (we’d go with aluminum tape), some black mosquito netting to see out of, and in a stroke of brilliance, a tablet that will display HAL’s unblinking eye to con attendees. If you’re extraordinarily clever, it might be possible to sample lines from the movie and play them through the tablet. This is, unfortunately, the best way to replicate the voice of HAL, at least until someone gets the money to have [Douglas Rain] sit in for some voice work.

The only drawback to the costume is the propensity for the wearer to hit their head on doorways and low thresholds. This problem could be solved simply by increasing the size of the costume, but then you’re back in monolith territory. So, what do you want to be, a murderous computer or a galactic swiss army knife?

A 4-bit Computer From Discrete Transistors

November 22, 2014 by 23 Comments

Anyone reading this uses computers, and a few very cool people have built their own computer out of chips, [zaphod] is doing something even cooler over on hackaday.io: he’s building a computer from discrete transistors.

Building a computer from individual components without chips isn’t something new – Minecraft players who aren’t into cheaty command blocks do it all the time, and there have been a few real-life builds that have rocked our socks. [zaphod] is following in this hallowed tradition by building a four-bit computer, complete with CPU, RAM, and ROM from transistors, diodes, resistors, wire, and a lot of solder.

The ROM for the computer is just a bunch of 16 DIP switches and 128 diodes, giving this computer 128 bits of storage. the RAM for this project is a bit of a hack – it’s an Arduino, but that’s only because [zaphod] doesn’t want to solder 640 transistors just yet. This setup does have its advantages, though: the entire contents of memory can be dumped to a computer through a serial monitor. The ALU is a 4-bit ripple-carry adder/subtractor, with plans for a comparison unit that will be responsible for JMP.

The project hasn’t been without its problems – the first design of the demux for the ROM access logic resulted in a jungle of wires, gates, and connections that [zaphod] couldn’t get a usable signal out of because of the limited gate fan-out of his gates. After looking at the problem, [zaphod] decided to look at how real demuxes were constructed, and eventually hit upon the correct way of doing things – inverters and ANDs.

It’s a beautiful project, and something that [zaphod] has been working for months on. He’s getting close to complete, if you don’t count soldering up the RAM, and already has a crude Larson scanner worked out.

Doing Unsafe Things With A Laser Watch

November 22, 2014 by 15 Comments

[Pierce Brosnan]-era James Bond had a beautiful Omega wristwatch. Of course as with any Bond gadget, it couldn’t just tell time; it needed to do something else. This watch had a laser, and [Patrick] figured he could replicate this build.

This is apretty normal 1.5W laser diode build, stuffed into a wrist-mountable device that will kill balloons. This is really a watch, though: press a button and this thing will tell time.

In the video below, [Patrick] goes over what damage this watch can do. He manages to pop some black balloons, burn holes in a CD case, light a few matches, cut cellotape, and put tiny burn marks in his wall. The battery won’t last long – just a few minutes – but more than enough to propel [Patrick] into Youtube stardom.

There are no plans or tutorials for the build, but the teardown [Patrick] shows is pretty impressive. To stuff a laser diode, battery, and clock into a watch-sized compartment, [Patrick] needed to turn down the metal buttons to fit everything into his watch case.

Because the comments for this post will invariable fill up with concern trolls, we’re just going to say, yes, this is incredibly unsafe, no one should ever do this, and it probably kills puppies.

 

Serial Surgery Saves Wacom Tablet From Landfill

November 22, 2014 by 9 Comments

Years ago, [Greg] got a Wacom Artpad II graphics tablet through Freecycle. What’s the catch, you ask? The stylus was long gone. When he found out how expensive a direct replacement would be, the tablet was laid to rest in his spare parts box. Fast forward a few years to the era of the phone-tablet hybrid and [Greg]’s subsequent realization that some of them use Wacom stylii. Eight bucks later, he’s in business, except that the tablet is serial. Wacom no longer supports serial tablets, so he had to convert it to USB.

With the help of the WaxBee project and a Teensy 2.0, he would be able to emulate an Intuous2 tablet by sniffing and re-encoding the packets.  Things got a little hairy when he went under the hood to remove the ADM202 TTL-to-RS232 chip with a Dremel—he accidentally gouged some of the pads it sat on as well as a few of the traces. Feeling frustrated, [Greg] took some high-res pictures of the board and posted them to a message board. As it turns out, those pictures helped him recreate the traces and get the tablet running. A little big of glue and tape later, he was in business. [Greg] even gave himself access to reprogram the Teensy.