[Old bit collector] is giving up control of his radio dial to the Internet. He combined a couple of Parallax products which now allow him to tune, adjust volume, and toggle the power for an FM radio receiver.

The setup is pretty simple. An FM receiver module is mounted in the breadboard seen above which helps to break out its control pins. Those are connected to a Parallax Spinnarette web server board. It’s auxiliary I/O pins are controlled via a web interface that he set up and plans to operate with the browser on his Android phone. But as you can see after the break, any web browser works as long as you know the correct address.

This is pretty good if you’re on a quest to make everything controllable from your smart phone. But we would love to use the concept to make our own streaming radio. You’d be able to tune in to all of your local stations from anywhere in the world.

When you need a mechanism to detect the water level within a container or tank, you have several different options. Most people opt for a simple float or probe that sits in the water, while others use optics to sense when the water is reaching an undesired level.

This device built by [Danilo Abbasciano] uses a Parallax Ping sensor instead. If the sensor is placed at the top of a well, cistern, or other water container, it can accurately calculate the height and volume of the fluid inside. This is done by using the Ping’s readings in conjunction with a few values already known to the user, namely the dimensions of the container.

In his implementation, the readings are relayed to a simple LCD panel for easy viewing, and a small piezo speaker is used to sound an alarm when the water level reaches a predefined threshold. This sort of measuring device can be quite useful in situations where a contact-based sensor would be subject to chemicals and corrosion, or where contamination is a concern.

[Randall Munroe], the guy behind our favorite web comic xkcd, gave us yet another great project idea that falls on the heels of securing our valuables and silencing loud car stereos. The xkcd forum has been talking about how to implement this, and we’d like to hear what Hack A Day readers think about this idea.

The project isn’t much different from 3D photography. [Carl Pisaturo] has done a lot of art and experimentation based on this idea that basically amounted to largish binoculars. A poster on the xkcd forum has already built this using mirrors, but we’re wondering how much the parallax can be increased with this method. Two cameras and a smart phone would also allow automatic pan and tilt that corresponds to head movement.

We’re not quite sure if this idea can be applied to astronomy. The angular resolution of the human eye is around one arc minute, every star except for the Sun has an annual parallax less than one arc second. If anyone wants to try this out with a longer baseline (From Earth to Pluto for example), we would suggest simulating this in Stellarium. Seeing the moon as a sphere would be possible with a few hundred miles between cameras, though.

Tell us how you would build this in the comments, and be sure to send in your write-up if you manage to build it. We’ll put it up right away.

Thanks to [Theon144] for sending this in.

EDIT: Because the comments are actually bearing fruit, check out the thread on the Hack A Day forums for this post: link.

It looks like Radio Shack is pretty serious about their new found commitment to their focus on the DIY, inventor, creator and geek demographics. [Ken Gracey], Parallax forum guru, put up a post on the Parallax stuff that will be sold at Radio Shack. Everything is priced, “below spousal approval level,” but no word on what those prices are.

Here’s the (probably not conclusive) list we gleaned from the pics: 2-axis joystick, gyroscope, GPS, compass and altimeter modules, an infrared sensor, 2×16 backlit LCD, BASIC stamp 2 board, and an XBee 2-pack that we assume would be priced above girlfriend approval levels.

We’re curious about how many (and in what quantity) of these items will be stocked at the East Nowheresville strip mall, and again there’s no mention of improving the selection of individual components.

At Hack A Day, we were thinking how amazing a Radio Shack ‘component vending machine’ would be. A modified pick and place machine that will dole out caps, resistors, other components, and has the potential to be competitive with online stores. Anyone feel like sending that suggestion in?

We have seen quite a few automated Etch-a-Sketch machines in our time, but when [Jason] wrote in to share his take on the subject, it came with a nice bribe attached. We are vain. It’s not something we are proud of, but when it comes to seeing the Hack a Day logo drawn out by a robot, consider us sold.

[Jason] has several CNC router builds under his belt, and thought it would be fun to automate his Etch-a-Sketch, a toy he loved as a child. He cut some gears and a face plate for the toy with his new CNC machine, then got busy programming his Propeller microcontroller to do his bidding.

A piece CNC software handles the conversion of a bitmap image to an outline, which is then converted to a CNC cutting path. The cutting path is translated into x/y coordinates by a bit of C++ code, before being fed into the microcontroller, which is running a small SPIN application he calls RoboSketch. The Propeller takes care of the rest, quickly drawing the image or pattern to the Etch-a-Sketch.

Continue reading if you would like to see a video of [Jason’s] tribute to Hack a Day, and don’t miss some of our previous automated Etch-a-Sketch coverage if this is something on your to-do list.

[Dave] posted some pictures and videos of his ‘Nuntius’ robot on the Propeller forums. From the pictures it’s an impressive build, but to really appreciate [Dave]‘s skill, check out the Youtube demo.

The controller is a Propeller protoboard with bits of angle aluminum fastened together. Pots are positioned at the joints of the remote’s arm so the robot’s arm can mirror the shape of the remote. We usually see Armatron bots controlled via computer, or in the rare case of human control, a mouse. [Dave]‘s build just might be one of the first remote manipulator builds we’ve seen on Hack A Day.

On the robot side of the equation, another Propeller board, motors, and servos are all powered by a 12 V motorcycle battery. Attached to the end of the manipulator is a cheap 2.4 Ghz wireless camera that [Dave] says makes you feel like you’re in the movie The Abyss. While we doubt this robot would be very good for underwater exploration, it does look like some of the Bomb Disposal robots we’ve seen.

The Parallax Propeller is a pretty powerful MCU as [Dino] recently discovered in his latest Hack a Week installment. He wanted to build a simple robotics platform that he could use for testing out various sensors, and he figured he might as well learn about a different type of micro controller in the process.

He pieced together his robot using a pair of old Roomba motors he had sitting around, mounting them on a standard RadioShack project box. A Propeller MSR1 control board runs the show, and a Propeller PING sensor is used to get an idea of what the robot’s surroundings look like. He is an admitted newbie when it comes to using Propeller micro controllers, but [Dino] was able to give his robot some rudimentary object avoidance abilities fairly easily. A few small bugs aside, he had the robot up and running in short order, a testament to how easy it is to work with the Propeller platform.

Stick around to see a brief video covering the robot’s construction we have embedded below.

[Beth] had the idea for transmitting digital audio over S/PDIF on a Propeller a few years ago, but only just got around to a writeup. For that, we thank her.

The writeup has a marvelous walkthrough of the S/PDIF protocol and the problems associated with with generating the signal. S/PDIF is a relatively resource-intensive protocol – the signal is clocked at 64x the audio sample rate. That signal is doubled for biphase mark code, keeping everything in sync. [Beth] says the microcontroller would neet at least 24 MIPS of processing power just to generate the S/PDIF signal – processing audio would be another task altogether. Because of the processing power needed, and the weird clock rates needed, [Beth] decided to go with the Propeller. The implementation uses only one core of the Propeller, leaving another seven cores available for sound synthesis or even a visualization over VGA.

[Beth] admits this could be done with just about any microcontroller (although it would need to be clocked at a multiple of 4.096 MHz for a 32kHz audio stream), but we really appreciate the work that went into bit-banging this signal.

Video of [Nick] at Gadget Gangster playing around with digital audio on a Propeller after the break.

[Parker] was in need of a Propeller development board to make working on his projects easier. More often than not, when he needed to prototype something, he would pull the only one he had on hand from his home made pinball machine, and replace it when finished. This was time consuming and cumbersome, so he decided he needed a better way of doing things.

He looked into purchasing a Gadget Gangster proto board which allows you to use a Propeller much like an Arduino, complete with support for shields and the like. Unfortunately, they were sold out and he was in a hurry to finish up a project. Rather than wait, he decided to build his own proto board, which would be more flexible than the COTS version – allowing him to add things like an Analog to Digital converter without having to use a shield.

He looked around online and found some schematics to follow, and had his proto board constructed in no time. It gets the job done and looks quite clean, considering it was put together using perf board.

Keep reading to see a video walkthrough of the Propeller development board construction.

Instructables user [IAMTHEBOT] recently finished building his robot which can be controlled by a human using an R/C transmitter, via a PC, or through its built-in object avoidance system. The robot doesn’t seem to have a name, though Johnny Five might be appropriate.

The robot was built using plenty of erector set parts, as well as a Lynx motion tank tread kit. The robot is crammed full of controllers, including a Propeller USB servo controller which operates the arms, and a pair of Parallax motor controllers to manage the tread movement. A pair of Parallax Stamp controllers are used to drive these controllers as well as to manage the remainder of the robot’s functions.

The robot’s head consists of a custom pan and tilt wireless camera system, which allows him to drive it around from the comfort of his home, while watching the video stream on his PC. The robot also has the ability to roam around autonomously, avoiding objects using a ping sensor that can be mounted where the camera is currently located. It seems all that’s missing is Steve Guttenberg.

As you can see in the videos below, the robot manages pretty well on all sorts of surfaces, and even walks this guy’s dogs.

We asked for responses to our last Development Board post, and you all followed through. We got comments, forum posts, and emails filled with your opinions. Like last time, there is no way we could cover every board, so here are a few more that seemed to be popular crowd choices. Feel free to keep sending us your favorite boards, we may end up featuring them at a later date!

The Popular:

Parallax Propeller: We heard the loudest cries from the Parallax fans out there. The Propeller is a unique chip, in that it contains 8 cores called cogs which each take turns executing separate code. This design allows for disregarding of interrupt style programming in favor of assigning each core a specific task. There are a number of boards available, including Gadget Gangster’s platform as well as boards from Parallax. Thinking in terms of 8 cores rather than one may present a learning curve to some embedded programmers, though there are a number of code examples to pull from online to get beginners on their feet.

Atmel’s AT90USB and AT32U4 based boards: Atmel’s AT90USB and ATmega32U4 chips are common on low part count boards like the Teensy/Teensy++ because of their built-in hardware USB support, which means no FTDI or equivalent chip required. These development boards tend to be low-cost, easy to implement on a breadboard, and in cases such as the Teensy, are Arduino IDE compatible. The chips these boards are based on are also an excellent place for those trying their hand out at microcontroller circuit design for the first time because of their simplicity and low hardware requirements.

Microchip’s PIC line: Somehow, we managed to leave the entire Microchip crowd in the cold last time. A popular set of microcontrollers with a similar market segment to Atmel’s chips, these chips vary from the low-end and low-cost 8-bit series to the higher end 16 and 32-bit models. We received a good number of development board recommendations, all ranging in price, features, and ease of use. We’ll rely on comments and forum posts to help convince you what specific model to try.

[edit: Added the PicKit3 as per popular request]

The Powerful:

mbed: Possibly one of the most popular hobby development boards for ARM’s Cortex-M3 chip, the mbed features a similar footprint to the Teensy, but with a huge jump forward in power. The mbed includes hardware for a number of peripherals, including support for ethernet with the addition of an RJ-45 port. The major difference between the mbed and other similar boards is the entirely web-based IDE. We have previously reviewed the mbed, so for more details be sure to check it out.

Renesas’ RX62N RDK: Whenever a company gives away development boards for free, the community often jumps on the offer. Rather than the normal free barebones boards though, the RDK has a good number of on board peripherals, including an Ethernet port as well as a 3 axis accelerometer. Unfortunately you can’t get one for free anymore (at least not this contest), but from all we have heard from our readers, it may be worth investing in anyway.

The Maple: The Maple from LeafLabs is an excellent example of the effect open hardware tools such as the Arduino have had on the hobbyist environment. Featuring an ARM Cortex-M3, the Maple has plenty of processing power and also can brag that it has the same header layout as the Arduino. This means that almost all commercially available Arduino shields will work on the Maple, a major selling point for anyone who has invested into a well stocked Arduino setup but needs an injection of performance.

Bonus Points:

OpenWRT based routers: Often, projects need to be networked either by wire or wirelessly to operate as desired. Rather than buying a high-end development board with ethernet or Wi-Fi built-in, many readers suggested buying (or salvaging) any one of a number of low-cost wireless routers, and installing a custom linux based firmware on them. These boards often tend to have UARTs or USB ports originally meant for debugging available for expansion with sensors or other low-end microcontrollers. A hack in the true sense of the word, we applaud this sort of creativity. Some popular firmwares to check out would include DD-WRT, OpenWRT, and the Tomato firmware. Be sure to make sure support exists for your device before you go buying anything though.

FPGA boards: When we set out to cover development boards, we had microcontrollers in mind. However when it comes to signal processing, custom high-speed logic, or flexibility, FPGAs are an excellent choice. The two major players for hobbyists these days are Xilinx with their Spartan line, and Altera with their Cyclone line. Both companies offer their IDE for free, and it comes down to personal preference when choosing which way to go. Both companies also support SoC designs to implement virtual microcontrollers on the FPGA, which adds an additional layer of flexibility for any hobbyist or engineer. Chances are, most hobbyists will not need the performance of cutting edge FPGAs (or CPLDs), so keep an eye out for older development boards on sale, or development boards made by third parties.

Build your own: Although it may appear as a sort of “Get off my lawn” answer to our question, there is a lot to be said about building a development board from scratch. These days, many 8-bit or 32-bit microcontrollers require few if any external components to run in a basic mode, and can be combined with a JTAG or FTDI cable for programming and communication. There are countless tutorials on using perf-board or etching a board to make a custom circuit, and the experience is invaluable for breaking away from high cost development boards in simple projects.

[Jeff], fully acknowledging his inability to keep plants alive, has designed a system to help him out a little bit. The “Plant Whisperer” monitors water levels and notifies him if the plant needs attention. Actually, it notifies him either way. The plant whisperer uses real time text to speech to say one of several pre-programmed things, either proclaiming its happiness or requesting more water. He’s using a parallax propeller for the job as he says it is capable of handling the real time text to speech. We realize this is overkill, but we absolutely love it. The only improvement we would want would be to possibly use a pre-recorded voice for more clarity.  You can see a video of it in action after the break.

White board beats chalk board, LED marquee beats white board, and an LED white board trumps them all.

This hybrid lets you draw on the surface with dry erase markers while Conway’s game of life plays out underneath. [Bert] sent us this tip after seeing yesterday’s office marquee. This version is quite similar in appearance but the guts are very different. Inside you’ll find a Parallax SX28 microcontroller doing the heavy lifting. The display is multiplexed but they didn’t go with a common 595 shift register, but a beefier MAX6979 LED driver. We’re not too familiar with this part but it does have a lot of nice features like constant current, and automatic shutdown if serial data stalls for more than 1 second. This is a low-side driver so transistors are used to connect voltage to the rows; the opposite from the setup we looked at yesterday. This was built several years ago and is still working happily even though its permanent home is a breadboard. Source code can be found on this page.

[Billy's] work got new keys which he didn’t want to carry around with him. Instead he built this system to unlock the door via text message. It is based around a Spinneret Web Server which drives a servo motor. He’s rigged up a pipe hanger to add some leverage to the lock’s knob. We’re surprised that the servo has enough power to do the job here but the video after the break shows there’s really no problem. On the communication side of things [Billy] set up Twilio to wait for text messages from an approved list of senders, then used an HTML form to issue the unlock commands to the webserver.

[via Make]

The folks at [gadget gangster] have been working on an excellent set of tutorials for getting started with the Propeller chip itself, the open-source Propeller Platform Modules and the Spin programming language that’s used to control things. All of the basics and a growing selection of more advanced topics are covered in gorgeous detail, with most of the tutorials containing helpful photographs and screen shots, source code listings and video walk-throughs to help you understand what the authors are talking about.

Parallax is not new to the microcontroller game. Almost two decades ago, their BASIC Stamp embedded microcontroller was the springboard for many tinkerers. The Parallax Propeller is an easy-to-use microcontroller that’s been gaining popularity for a while now. Several Propeller support modules have hit the market recently, providing power supply and interface functions to the Propeller similar to how the popular Arduino platform interfaces with AVR microcontrollers.