When you hear the term Tricorder, you might think of Star Trek but I assure you, this is no toy prop. Keeping with the same concept of the Tricorder used on the TV show the Tricorder is about reading data, _lots_ of data. And that is what the Tricorder project aims to do, develop handheld devices that are fitted with lots of diverse sensors in order to observe them.
So far the project has produced a few different versions. The Mark 1, the Mark 2, etc. They are currently working on the Mark 5. Each version is pretty different from the other, and they all contain a wide variety of sensors such as atmospheric temperature, humidity, pressure and electromagnetic field, color, infra-red. And the obvious like GPS. They’re even working on developing their own sensors like this 3d printable mini spectrometer.
I know this awesome project is a few weeks old but I’m going to use the fact that Rupert recently posted an update as my excuse to share it on hackalizer. As the title implies the V-USB Media Volume Control project is using V-USB. V-USB is software which makes it possible to add low-speed USB to almost any AVR microcontroller without any additional hardware.
From selecting the perfect rotary encoder to designing and etching his own PCB and eventually making a custom enclosure, this project shows is all. Rupert explains some of the minor but important differences of the rotary encoder such as the number of detents and amount of force required to turn the knob and press the button. He also shares an important lesson on load capacitance with regards to the crystal on his home-brew board. Check out the build video after the break.
I guess you never grow out of playing with cardboard boxes. This man sized WALL-E robot just goes to show that you don’t have to spend a lot of money on material just to make a shell for your robots.
The WALL-E robot includes a custom 433Mhz transmitter and receiver which uses Holtek HT12E and HT12D encoder and decoders. Atmega8 and Atmega16 were used to format the data being transmitter. The robot comes to life with the help of motors and pneumatic cylinders.
The soda bottles sure looks hackerish if you ask me. I would like to see more details on the pneumatics used in this project. See more build photos after the break.
Why over-complicate things ? Sometimes all you need is something simple. Paul over at DorkBotPDX decided his Monty Python theme costume needed a little extra flair, so he built a tiny sound clip player using some transistors, a teensy 3.0, a battery, and a speaker.
The circuit is pretty simple, a 9V battery gets regulated down to 5v to run the teensy. The teensy does some quick pwm changing on a single pin while parsing a specially crafted audio file. The pwm pin fires into a single transistor that then fires either a PNP or a NPN transistor at 9V which turns a small pwm signal into a big pwm signal. The signal runs through a small inductor and decoupling cap to an 8 ohm speaker.
He’s got a schematic, a teensy 3.0 sketch, and instructions on how he converted the audio clip into the right format over on his blog. Check it out.
When prototyping with digital sensors and microcontrollers it’s common to need a logic level converter. If you ever find yourself needing to convert between 3.3v and 5v logic levels you’ll be happy to know Tom from Magic Smoke has you covered. In his tutorial he shows you how to build your own Stripboard I2C Logic Level Converter using 4 resistors, 2 MOSFETs, a strip board, and a few jumper wires.
However, the logic level converter isn’t what got my attention with this design. I hate prototyping on perfboards and stripboards. I’d much rather use DipTrace to capture my schematic and layout a PCB. Though, Tom may have changed my opinion about stripboards by introducing me to this online Stripboard Schematic Capture and Layout (alpha) editor.
We also stumbled across a downloadable Stripboard Design Editor which comes pre-loaded with your basic discrete components such as resistors, caps, transistors, and generic ICs. You can also create your own custom IC parts. It’s lacking some other common parts such as headers, jacks, and crystals.
The guys over at Bot Thoughts like using AVR micros, specifically ATTiny’s. Whats wrong with the ATTiny ? Well … It’s tiny! Meaning not a lot of code space. After reading this doc they put together some highlights.
While some of the tips may be pretty obvious (like compiling with -Os, let the compiler optimize for size) there are some other tips you may not have thought about. On the test code, they got their code down from 4.2k to 1.4k. The biggest chunk of savings came from not using floating point math, believe it or not you can accomplish a lot of float type math with just integers and you can save a bunch!
Jason has a working prototype for what he calls a openSip+puff. It’s meant to be a controller for people with disabilities. It will allow you to do things with your mouth by sucking in air and blowing out air.
It uses a pressure sensor and an ATmega32u4. It connects as a USB device so it can end up being a keyboard or mouse device (or some sort of button trigger or joystick). I think the code is still being hashed out but he’s making good progress.
It’s open source hardware, and he’s hoping to do a Kickstarter soon.