iFixit has done a tear down on the symbolic do-it-yourself Espresso machine, the Starbucks Barista. Believe it or not, there is not a single circuit board in the works. There doesn’t seem to be much to the Barista; A few switches, some solenoids, a heater, and one way spring valve among other things. The assembly of the device is very simple. It is noted that in a pinch it may be torn down with a pair of pliers and washer; in place of a flat head screw driver. We have pondered the possibilities of this machine numerous times, while enjoying a cup of cappuccino. Though most conversations end at the bottom of the cup, many survive such as this Silvia PID looped expresso machine. The very name “Mecha turbo crazy coffee roaster” seems to encapsulate the effects of caffeine quite adequately.

While researching solid state Tesla coils we stumbled across this old project. As you have probably guessed from the pictures, this coil is meant to actually play music. Knowing how to add eye catching flare, the coiler uses a Plexiglas frame turned light pipe; only to be complimented by an audio amplifier complete with graphic equalizer. There is a video of the coil in action on YouTube. We have covered singing tesla coils in the past. Other twists on the classics include the tesla coil guitar amp and a hand held plasm gun.

[Sprite_tm] automated a portion of serial hacking by sniffing out the baud rate using an ATtiny2313 and FT232 breakout board. The firmware assumes 8 data bits, no parity, and 1 stop bit (8N1). This is pretty much defacto among serial ports so it should work well, though some devices do use different settings. The auto detection routine can sniff rates as low as 110 baud and supports non standard rates. Released under GPLv3, the software is also supplied in hex format.  [Sprite_tm] has provided great project in past such as Working with VFDs, Controllable bristlebot, and AVR boost converter. Additional information regarding serial hacking after the break.

A great deal of electronics have an Achilles’ heel, known as a serial port. These embedded ports are often used during development to debug functions, load and upgrade firmware etc. At the very least circuit traces are generally brought out for automated testing purposes. Looking up chip pin outs and tracing circuits is one small step in serial hacking. After the traces are known the voltage level is then determined(CMOS,TTL,RS232,etc). Then a few tests are run on the port. These tests generally give indications regarding the potential of the port(does it have a driver, does it have a protocol, what is the baud, etc). If information regarding the baud and other criteria can not be found in the data sheet, [Sprite_tm]‘s method would certainly save a great deal of tedious time. Some controllers, like the 68HCxx may have a boot ROM which eliminates most of the guess work in setting up the serial port. We use the Null-modem emulator project (com0com) almost daily to help sort various serial problems. This is highly recommended,  for anyone spending a considerable amount of time with serial devices.

[WaveRider] is using a type of phase shift keying called BPSK to transmit digital sound and video for remote telemetry. Though a higher signal to noise ratio (SNR) is generally sought after with communications, legal limitations are imposed on total radiated power. To balance the two headed beast, he opted out on frequency shift keying due to binary shift keying’s ability to work with lower SNR. This adds the difficulty of properly reconstructing the digital signal at the receiver. A PLL based carrier regeneration circuit is used to reconstruct the signal. Using the Rabit2000 processor as the host controller on both transmitter and receiver, 96KB/Sec serial data is obtained. On the other side of the spectrum is the Homemade regenerative tube radio.

[RagingComputer] built this 1-wire attic cooling fan. He’s using an Ubuntu server loaded with OWFS to control everything. The 1-wire temperature sensor is interfaced using USB while a serial x10 module sends out commands to be received by another x10 module near the fan. Back in the day we had covered a linux home automation project. We also covered HVAC hacks such as the smart attic fan and a 1-Wire HVAC monitoring system.

The 1-Wire HVAC monitoring system is for residential Geothermal HVAC systems. This project utilizes the so called 1-wire temperature sensor. A single board computer handles the brunt of the work including web accessible trend data. With access to the underling temperatures, the over all system performance may be gauged. Earlier this year we covered a HVAC web enabled monitor that adds an element of control. As the industry adopts modern control architectures, we hope to see more HVAC hacks around.

The Music visualizer is actually a second build based on an earlier design[Thanks Roger]. The build was influenced by Zyra’s How to make an oscilloscope out of a television. The hack is quite simple, patch the output of an amplifier into the vertical deflection coils of the CRT. This is a good use for that old TV you may have laying around  but don’t want to recycle it just yet. While on the subject we had covered the Mac SE/30 audio visualizer in 2006. For those looking for something a little more hard core, here is a bit about Homemade cathode ray tubes.

4D  Systems micro drive provides both raw and FAT level access to microSD cards. The module contains a dedicated host controller that transforms what may be an otherwise intimidating card spec into a group of simple serial commands. With a wide supply range of 3.6-5.5 and .1″ lead spacing, this should be cake walk to tinker with. The device doesn’t support FAT32 yet. According to the GOLDELOX-DOS command set page 9, “FAT32 is currently not supported, if you mount a FAT32 formatted disk, you will not be able to access it at all, both FAT and RAW commands will fail”. At the moment the device seems limited at 2GB FAT16 partitions. This sure does seem like cheating after implementing SPI and Nibble mode SD card protocols.

[via Electronics-Lab.Com thanks mozzwald]

We found this Arduino AVR ISP programmer particularly interesting. AVR microcontrollers can utilize an interface called In-System-Programming. ISP allows the chip to be programmed or reprogrammed while in an actual circuit via a pin header. Atmel’s solution is the AVR ISP MKII programing tool. The MKII can also be reprogrammed just as an AVR. The difference here is that most people are not likely to modify the MKII to be used as anything but a programmer. On the other hand if you already have the Arduino, fetch the avr.isp.03 firmware and AVRdude. Then program a device, for example an ATtiny13 using the Ardunio as the programmer. All the project information is provided under the CC BY-NC-SA 3.0 license. On a related note we covered a Microcontroller cheat sheet which covers AVR devices and ISP pinouts.

There are no microcontrollers in this project. In fact you wont find a single transistor. This classic regenerative tube radio, modeled after an early 20th century homebrew is complete with schematic and additional photos. For those who are not familiar with tube designs and for simplicity, the regeneration circuit can be thought of as feedback though this relation may be argued. Read the rest after the break which includes a crash course in tube operation.

A basic vacuum tube generally consists of a heater, grid, and plate. A current is passed through the heater which as the name suggest, creates heat. This allows electrons to “boil off” under proper conditions. That is the hot heater emits electrons when the grid and plate are positive potential. Opposite charges attract so the electron is attracted towards the grid and plate. The grid has holes very much like a screen door does. Some of the electrons pass through these holes missing the grid and strike the plate. The greater the electrical potential the greater the attractive force in the grid and plate. When an electron is permitted to move from one potential to another an electrical circuit is created. This circuit forms the basics behind vacuum tube operation.

With that said, the project uses a heater powered from two D size batteries. There doesn’t seem to mention of the plate source, though we suspect a few 9 volt batteries wired in series does the trick. Some of the newer commercialized radios (World War II era) operated from considerably higher heater and plate voltage potentials, rendering the common shock hazards associated with tube designs. Tuning is accomplished with an air cap and home made variocoupler. We covered a VFD based regenerative reciever earlier this year.

This project provides an opportunity to conduct near space experiments. The flight computer, BalloonSat Extreme, is controlled by a BASIC Stamp 2pe. The complete BOM with PCB artwork is provided. There is enough hardware to control cameras, servos, a Gps, and five digital I/O. The computer is also equipped with a 12 bit ADC to log experiment results. The device seems limited to 30KB of storage. Though the author suggests this memory limitation is more than adequate, we are wondering if an implementation of the Nyquist sampling theorem is in use at all. For further reading the author has provided information regarding Amateur Radio High Altitude Ballooning.

[via adafruit]

Here is a classic project used to increase wireless signal strength. Cantennas focus using a waveguide very much like a magnifying glass focuses light. [Robert] made a Natural Light beer cantenna, pictured in the upper left. His approach used three beer cans, a paper towel holder, and a shower curtain rod. On the tipline, he noted a signal boost from 11Mbps to 54Mbps. This is certainly something we can hack together if our room lacks adequate signal. Read about parabolic and seeking versions after the break.

The lower right image is an example of a parabolic soup cantenna constructed using an old satellite dish. No figures seem to be cited, though the construction is worth noting. We’ve had success with old satellite dishes in the past. The upper right and lower left pictures are scanning Cantennas. They use servos to seek out stronger connections by moving and checking the signal strength. Below is an in line video of the lower left cantenna while scanning. Maybe you want to know How to build a tin can waveguide WiFi Antenna. All the instructions are provided complete with a rough cost break down, and the site has a calculator to determine cut off frequencies given a can’s diameter.

[Maarten] told us about a C64 USB keyboard that was modified to be used as a standard input device. An interesting aspect of the project is the use of V-USB (formerly known as AVR-USB). V-USB is a software only approach to slow speed USB HID. In essence this is a two fold mod, The C64 keyboard is patched to a PC, and an off the shelf AVR is software-hacked to bit bang the USB communications. The author notes an initial problem with multiple key presses that was later corrected in the application. For the other side of the spectrum, we had covered the C64 twittering client, and a commodore 64 laptop.

Capacitive discharge cutting provides more control than linear transformer versions. A very large capacitor is charged to a precise voltage and then discharged through the material to produce a controlled cut. The same device can also be used for spot and tab welding. A video of copper roof flashing being cut is embedded below. An example of a linear transformer can be found in our our How-to: build your own spot welder.

This antenna tuner is controlled remotely using geared motors and legos. The tuner needed to be closer to the antenna for performance reasons. This created a problem; most of the radio gear is inside while the tuner is outside. The gear motors and Legos combine to form a closed loop servo, operating two air core caps and an inductor switch. A control box placed near the radio is hard wired to the modded tuner outside. We would like to see something like this under gesture control using the Wii MotionPlus + Arduino.