Binary Clock Would Make Doc Brown Proud

January 8, 2015 by Rick Osgood 20 Comments

[Brett] was looking for a way to improve on an old binary clock project from 1996. His original clock used green LEDs to denote between a one or a zero. If the LED was lit up, that indicated a one. The problem was that the LEDs were too dim to be able to read them accurately from afar. He’s been wanting to improve on his project using seven segment displays, but until recently it has been cost prohibitive.

[Brett] wanted his new project to use 24 seven segment displays. Three rows of eight displays. To build something like this from basic components would require the ability to switch many different LEDs for each of the seven segment displays. [Brett] instead decided to make things easier by using seven segment display modules available from Tindie. These modules each contain eight displays and are controllable via a single serial line.

The clock’s brain is an ATmega328 running Arduino. The controller keeps accurate time using a DCF77 receiver module and a DCF77 Arduino library. The clock comes with three display modes. [Brett] didn’t want and physical buttons on his beautiful new clock, so he opted to use remote control instead. The Arduino is connected to a 433MHz receiver, which came paired with a small remote. Now [Brett] can change display modes using a remote control.

A secondary monochrome LCD display is used to display debugging information. It displays the time and date in a more easily readable format, as well as time sync information, signal quality, and other useful information. The whole thing is housed in a sleek black case, giving it a professional look.

Digital To Analog To Digital To Analog To Digital Conversion

January 3, 2015 by Brian Benchoff 9 Comments

[Andy] had the idea of turning a mixing desk into a MIDI controller. At first glance, this idea seems extremely practical – mixers are a great way to get a lot of dials and faders in a cheap, compact, and robust enclosure. Exactly how you turn a mixer into a MIDI device is what’s important. This build might not be the most efficient, but it does have the best name ever: digital to analog to digital to analog to digital conversion.

The process starts by generating a sine wave on an Arduino with some direct digital synthesis. A 480 Hz square wave is generated on an ATTiny85. Both of these signals are then fed into a 74LS08 AND gate. According to the schematic [Andy] posted, these signals are going into two different gates, with the other input of the gate pulled high. The output of the gate is then sent through a pair of resistors and combined to the ‘audio out’ signal. [Andy] says this is ‘spine-crawling’ for people who do this professionally. If anyone knows what this part of the circuit actually does, please leave a note in the comments.

The signal from the AND gates is then fed into the mixer and sent out to the analog input of another Arduino. This Arduino converts the audio coming out of the mixer to frequencies using a Fast Hartley Transform. With a binary representation of what’s happening inside the mixer, [Andy] has something that can be converted into MIDI.

[Andy] put up a demo of this circuit working. He’s connected the MIDI out to Abelton and can modify MIDI parameters using an audio mixer. Video of that below if you’re still trying to wrap your head around this one.

Continue reading “Digital To Analog To Digital To Analog To Digital Conversion” →

Controlling Nokia Phones With Arduino

January 1, 2015 by Will Sweatman 9 Comments

While [Ilias Giechaskiel] was waiting for his SIM900 shield to arrive, he decided to see what he could do with an old Nokia 6310i and an Arduino. He was researching how to send automated SMS text messages for a home security project, and found it was possible to send AT commands via the headphone jack of Motorola phones. But unfortunately Nokia did not support this, as they use a protocol known as FBus. With little information to go on, [Ilias] was able to break down the complicated protocol and take control with his Arduino.

With the connections in place, [Ilias] was able to communicate with the Nokia phone using a program called Gnokii — a utility written specifically for controlling the phone with a computer. Using the Arduino as an intermediary, he was eventually able tap into the FBus and send SMS messages.

Be sure to check out his blog as [Ilias] goes into great detail on how Nokia’s FBus protocol works, and provides all source code needed to replicate his hack. There is also a video demonstration at the end showing the hack in action.

What’s In A Name?

January 1, 2015 by Kristina Panos 37 Comments

Take thirty seconds out of your day and try to make fun of the last name of the person who wrote this post. Go ahead, it’s okay. You probably won’t need more than ten seconds to come up with something that uses the same first, middle, and last letter. While nothing can be done to prevent last name-based harassment in the schoolyard, first names are another matter. [Ranthalion] recently dined with friends who are expecting twins and have yet to decide on names for them. It’s difficult enough to name one child, and we can imagine ourselves spending an entire day or two getting funny name pairs for twins out of our systems (Flora and Fauna, Scylla and Charybdis, &c). With the baby shower two weeks away, [Ranthalion] had to act fast in creating his Baby Namer.

It needed to be something he could make relatively cheaply with parts on hand. Although he made a prototype with an Arduino, he wasn’t about to just give one away. [Ranthalion]’s Baby Namer uses two arrays, one with awesome names like, well, Sharktooth Chompenstein, and one with regular names from census data such as Bob, Carol, Ted, and Alice. Things got a bit hairy with the volume of names he got from census data and he learned the value of PROGMEM for storing things.

On startup, it displays four names from the Awesome pile as a gag and then pulls from the Ho-Hum group. However, each time it pulls a regular name, there’s a 25% chance that part of an Awesome name will be included. Get thee to the gits and have a laugh at other names on the Awesome list.

Z80, CP/M, And FAT File Formats

December 30, 2014 by Brian Benchoff 18 Comments

[Gary Kildall] and CP/M are the great ‘also ran’ of the computing world; CP/M could run on thousands of different 1980s computers, and [Gary] saw a few million in revenue each year thanks to CP/M’s popularity. Microsoft, DOS, and circumstances have relegated [Kildall] and CP/M to a rather long footnote in the history of microcomputers, but that doesn’t mean CP/M is completely dead yet. [Marcelo] wrote a Z80 emulator running CP/M inside an Arduino Due, and he did it in such a way that it’s actually convenient and useful to use.

Instead of using CP/M disk images, [Marcelo]’s emulator emulates CP/M disk drives on top of a regular FAT file system. Drives are mapped to folders in the FAT file system, so a folder named ‘A’ will show up as the A: disk in CP/M. Drives up to P: are supported, the maximum number of drives available under CP/M. The BIOS resides in the root directory of the SD card, and so far Microsoft Basic, Turbo Pascal, UCD Micromumps, and Wordstar work just fine.

The Arduino project was built upon one of [Marcelo]’s earlier projects that put the CP/M emulator on Windows. The version for the Due works exactly how you think it would, with a serial connection and terminal emulator providing the IO, and the huge amount of processing power and RAM available on the Due doing all the heavy lifting.

What Is The Matrix…Clock?

December 29, 2014 by Marsh 18 Comments

We’re surprised we haven’t seen this kind of clock before, or maybe we have, but forgot about it in the dark filing cabinets of our minds. The above picture of [danjhamer’s] Matrix Clock doesn’t quite do it justice, because this is a clock that doesn’t just tick away and idly update the minutes/hours.

Instead, a familiar Matrix-esque rain animation swoops in from above, exchanging old numbers for new. For the most part, the build is what you would expect: a 16×8 LED Matrix display driven by a TLC5920 LED driver, with an Arduino that uses a DS1307 RTC (real-time clock) with a coin cell battery to keep track of time when not powered through USB. [danjhamer] has also created a 3D-printed enclosure as well as added a piezo speaker to allow the clock to chime off customizable musical alarms.

You can find schematics and other details on his Hackaday.io project page, but first, swing down below the jump to see more of the clock’s simple but awesome animations.

Continue reading “What Is The Matrix…Clock?” →

Captain Hermano’s Mystery Box Is Full Of Puzzles

December 28, 2014 by Rick Osgood 9 Comments

[Raffi] needed a birthday present idea but he wanted to do something extra special. He realized that a big part of gift giving is the anticipation and excitement of opening the present. In order to prolong this experience, [Raffi] built an electronic puzzle box. The box contains the final gift, but first a series of puzzles must be solved in order to open the box.

The project runs on an Arduino Mega. This is hooked up to several sensors, including a temperature sensor, GPS unit, and CO sensor. There is also an LCD screen and numeric keypad for user input and output. The project page contains a flow chart that shows all of the puzzles and their solutions. One of the more interesting puzzles requires the user to blow tobacco smoke into a tube. The CO sensor detects the smoke and unlocks the next puzzle.

Some of the puzzles require interacting with outside systems. For example, one puzzle requires the user to send an email to the fictional Captain Hermano’s email address. If the correct keyword is included in the email, the user will receive a reply with the code to enter into the box. Another puzzle requires the user to call a particular phone number and listen for another riddle. We’ve included the video demonstration below.

This isn’t the first puzzle box we’ve seen, but each one has its own special flair. This one is very well made and looks like a lot of care was put into it. We’ve seen another that uses only discrete components. We’ve seen yet another that uses Morse code. Continue reading “Captain Hermano’s Mystery Box Is Full Of Puzzles” →