Punky GPS Gets The Steam Built Up For Geocaching

While getting geared up for geocaching [Folkert van Heusden] decided he didn’t want to get one of those run of the mill GPS modules, and being inspired by steam punk set out and made his own.

Starting with an antique wooden box, and adding an Arduino, GPS module, and LiPo battery to make the brains. The user interface consists of good ‘ole toggle switches and a pair of quad seven segment displays to enter, and check longitude and latitude.

To top off the retro vibe of the machine two analog current meters were repurposed to indicate not only direction, but also distance, which we think is pretty spiffy. Everything was placed in a laser cut wooden control panel, which lend to the old-time feel of the entire project.

Quite a bit of wire and a few sticks of hot glue later and [Folkert] is off and ready for an adventure!

Automatic Water for Your Pets

If you have livestock or outdoor pets you know how important it is to keep them watered, but also know that sometimes you are not around when the trough runs dry. [Buddy] solves this inconvenience with a trip to the hardware store and some creativity.

The automatic water filler is made from some PVC pipe, brass fittings, a faucet supply and a toilet float valve. The PVC is arranged into a hook shape, a fitting is put on one end for a standard garden hose. On the other end a bit of adapting is needed to convert the PVC into a faucet supply, where the toilet valve is hooked up. Now whenever your thirsty beasts get the water too low, the float lowers and tops off the watering hole with fresh H20. That sure beats running out there every day to make sure, especially with summer just around the bend.

Who couldn’t use a little more screen space?

Text LCD’s are handy for any occasion, a printer port on your PC is also darn handy as well. Mix together and add in a splash of linux and you get a very handy Linux device driver for a 16×2 LCD connected to the parallel port.

Electrically the LCD is wired up in a typical 4 bit mode, this allows the parallel port to use its 8 bit data register to write data, but also control the Register Select and Enable pins. Next is to make a module for linux to use, it seems like pretty standard fair for this type of screen.

Make the driver, insert the module so it can be loaded, and add a node so you know where to find it later, and your only an “echo Hello > /dev/my_lcd” away from finding all sorts of creative uses for your new external display.

Passive Filters, Data Transmission and Equalization Oh My!

[Shahriar] is back with a new “The Signal Path” video. It has been a few months but it is okay because his videos are always packed full of good information. Some new equipment has been added to his lab and as an added bonus a quick tour of the equipment is included at the start, which is great if you like drooling over sweet machines.

The real focus of the video is high speed data communications, getting up into the GHz per second range. [Shahriar] covers filtering techniques from simple RC low pass filters to pretty complex microwave filters. Explaining frequency and time domain measurements of a 1.5Gbps signal through a low bandwidth channel. He also shows how equalization can be used to overcome low bandwidth limitations.

It is an hour long video jam packed with information, so you might want to set aside some time and have a pencil on hand before going in. It is well worth it though, so join us after the break.

Continue reading “Passive Filters, Data Transmission and Equalization Oh My!”

Dye Mac Dye!

Fabric dye is one of those products where it keeps popping up for unintended uses, we have seen it coloring printed circuit boards, and now a Macintosh computer? [The Brain]’s project to add a little color to his Macbook has been done before, but he chooses to do it in a different way, which comes down to a little bit of sandpaper.

You could go ahead and dye the Macbook plastics as is, but that thick layer of glossy plastic is going to take much more time to penetrate and its going to resist taking the color, so it might end up splotchy. The simple solution to this is to just sand off the gloss, that way the color has much less of a barrier to dye the plastic. Once the protective gloss shell is sanded away and cleaned throughly, Rit brand fabric dye is added to a pan of water and set on the stove to boil.

While most of the case plastics are thick and tough enough to withstand some heat, care does need to be taken when dealing with thin soft parts like the display bezel. After about 45 min the parts are dyed and popping with super bright orange color in record time.

Attiny25 Based Function Generator Causes a Wave

Function generators are a handy bench tool to have around, and while you can usually cobble something together that works, it is much more handy to grab a device when you need it. Thats where this function generator sent to us by [Mohonri]comes in. Based around a ATTiny25 and a rail to rail op amp which is able to replicate frequencies from 1Hz to about 40KHz, in square, triangle, and sinewaves simultaneously.

The function generator also features independent amplitude control on each output. And it’s all on one palm-sized, single-sided PCB. The main part of the code is split into two parts: the main loop gets the inputs and constructs a waveform table in SRAM, and then an ISR reads that table and outputs it to one of the timers, which produces a PWM output, which is low-pass-filtered and then passes through a potentiometer (for amplitude control) and then to an op-amp before landing on a set of terminals.

Though its not 100% perfect, trading speed for a 6 bit resolution, it should be more than enough for most electronic projects. You can pick it up in kit form from the on-line shop, but schematics, software and PCB layouts are also available for download.

Designing a Smarter RF transceiver

Two  months ago we featured a transceiver based on the Microchip MRF49XA, and a lot of feedback was sent to [hpux735] requesting that some brains be added onto the system. [hpux735] decided that if he was going to do it, might as well go the distance and make a make a native USB transceiver.

The prototype model is designed for use with the Atmel AT90USBKey, and uses the LUFA USB framework. The protocol and packet format was revised, and a Hamming Code implementation was built using look-up tables to give error control. Finally once the prototype was ready to go [hpux735] created some awesome little PCB’s that contain the AVR, radio, antenna hookups, and blinky lights (no project is complete without blinky lights) are all ready to go when you are.

This project has come quite a long way, covers 3 blog pages, uses a fair bit of ribbon cable, but you just got to love when a plan comes together.