Choosing Your Microcontroller (Part 2)

Last time, we talked about two sets of microcontrollers, the Arduino Family, and the .net framework family. Today, let's talk about some more.


     PIC microcontrollers are found quite commonly in end user products. They are also used quite frequently in college level electrical engineering courses. These little devices aren't frequently packaged with a board, so using these chips requires some knowledge of being able to build, program, and test circuits. There are, however, a large variety of chips to choose from, with various sizes and functions to suit any need.
     The community around PIC's is fairly great, not necessarily for the reason one would think. The programming environment for PIC's is your basic C language  However, PIC's have been known for what a pain their coding can actually be. Many very simple things that are done with other devices, are quite complicated to achieve in PIC code. These devices are not well suited to the novice programmer or engineer, so beware.

     MSP microcontrollers are extremely power efficient devices by Texas Instruments. These devices aren't as well known, I've found, as the other controllers I've mentioned. They're quite application specific, if you're looking to build your device using as little power as possible. Still, they're great little devices that offer a lot of potential, even if you're not looking to stretch that battery as far as possible. There are a few platform options you have for MSP's. One of which is the Launch Pad, the cheapest microcontroller test board I have ever found. Another such platform is an MSP based watch, the eZ430 Chronos, which includes a 3-axis accelerometer, barometer, and wireless transceivers, as well as being a watch. Most though, like PIC's, are just single chips with varying numbers of pins and functionality.
     Also like the PIC's, these are programmed in C, but can also be programmed in assembly. These can also be quite difficult to utilize some of the functionality at times, but I maintain they're still easier to use than PIC's. The community around MSP's tends to be a little more professional, as these are used more in measurement and extreme longevity projects. Again, not the sort of device the beginning programmer should necessarily be getting into.

     Basic Stamps, by Parallax, have been in the microcontroller game longer than any other I have mentioned. They're one of the first microcontrollers I was exposed to in high school. They have what is probably the largest community of people working and willing to help others on their projects. The company behind these boards, parallax, also develops large amount of externals like servos, sensors and even some Arduino-like shields. The downside to these boards are that they can be quite expensive for not all that much board. The basic "stamp" is a tiny microcontroller, that doesn't include a breadboard or a programmer, is $30.
     The upside to these boards are that they're extremely easy to get into. The getting started kits that they sell include all sorts of tiny bits, IC's, servos, and LED's with a very well written guide explaining all the steps and why everything works. The boards themselves are programmed in a variant of BASIC, which makes following code fairly...basic. If you're looking to get started with microcontrollers, and you have some extra money around, and you don't want an Arduino, then I recommend the BASIC stamp. But splurge and get the "Getting Started" kit.

     The last microcontroller I'm going to talk about is another one from Parallax, the Propeller chip. These are probably some of the most powerful microcontrollers you can buy, offering 8 cores of processing power each at 20 million instructions per second (MIPS). These are definitely for the more advanced hobbyist requiring more knowledge of wiring and programming than the novice. There are a huge number of peripherals to cater to the processor's capabilities including the ability to: generate video signals, interpret device signals such as mouses and keyboards, and easy interface with other devices.
     When it comes to programming these chips, you've got some choices. There is the "Spin Language" aimed more at beginners to the chip, but there is also the capability to program the devices in assembly. Like the BASIC Stamp, there are also such kits that display the various abilities of the chip, so if you're interested in this area, I'd recommend getting on of those. There are such kits that allow you to build basic computers and game consoles. It's the processor behind the YBox, that wonderful little device. So, the Propeller chip is something a little more experienced programmers and hobbyists would enjoy, with its extra power and capabilities.

Choosing Your Microcontroller (Part 1)

When it comes to choosing your microcontroller, you've got plenty of options.

True Cloud Storage

I've had a bit of a problem with the concept of cloud storage. My problem is that, the data has to exist in a physical form somewhere. It's only through the internet that one is able to access that stored information. My thought was there must be some way to store information actually in the air.

The concept is based around the old form of memory, called delay line memory. The main theory behind it is that there is a tube filled with some fluid, often mercury. One one end of the tube is an acoustic transducer that takes data and converts it into sound pulses that travel through the mercury in waves. On the other end of the tube is another acoustic transducer that takes those waves of mercury, and converts them back into electrical impulses, which are then processed then passed back to the first transducer to start the process over again. Would it be possible to apply the same principle to cloud storage.

The operative stage is the delay within the system. The problem is that electronics are built to remove as much delay as possible. There is one system where delay is almost impossible to get rid of. The idea of latency is something that exists in wireless networks, especially less well optimized networks spread over greater distances. I've recently purchased some cheap wireless transmitters and receivers that I plan to use to test my theory.

Cheaper Bits

I'm a basement hacker. I don't have a lot of money lying around to be able to spend on numerous components and measurement devices that I cannot see an immediate need for. Thus I'm always on the lookout to find really cheap stuff, when I'm not building it myself. Ebay has proved to be an excellent source of cheap bits. One such example is a pair of wireless components. If you've seen my senior capstone project, I'm plugging myself a lot tonight, you'd know that I used such a pair of devices to communicate between components. The pair of transmitter and receiver cost about $9. On Ebay, I found both for under $2, with free shipping. There are all sorts of other great components out there as well, from IC's to sensors.

My point is this. If you're looking to get some parts, yes, DigiKey, Mouser, and SparkFun, are all great places to shop. However, if you're willing to spend a little more time shopping around, there may be some better deals.

DIY Oscilloscope Done

As promised here are all of the files necessary to make your own oscilloscope. This device limits the output of the signal so that you can pass it to an app on your phone or tablet. I'm still doing a little bit of testing with the device itself, testing at what voltages it stops being safe. Basically, don't run this thing above 50 volts peak to peak. Remember that I take no responsibility for what this does to your phone or tablet if you misuse the device.

Maker Faire 2012

Maker Faire 2012 New York was just as much fun this year, as it was the last two. You can check out a few of the pictures I snapped while there here.

Well to start, there is, as always, a great number of 3D printers this year. MakerBot has produced a new model with a much higher level of detail. There are new companies with their own printers, trying to reduce the cost of producing the device. There was even a printer large enough to print a person inside of.

Arduino continues to have a large presence. There are more and more companies either trying to create shields, add-ons that capitalize on the device's popularity, or create an Arduino clone based off another processor. Parallax is one such company, trying to add shields to their current lineup of products. A PIC based Arduino system is being worked on by another company, which looks promising; anything that can make PIC more bearable, is a good thing. The Arduino Due, the ARM-based Arduino, is going to be released in a few weeks.

There seems to be more items to aimed towards the younger maker audience this year. Activities, trying to get kids involved, painting, alternative energies, even Disney's Phineas and Ferb were there to greet the kids.

All in all, a great way to spend the weekend. I will be posting the details for the DIY oscilloscope tomorrow, so stay tuned for that.

September Update

It's been almost 2 months since my last post, and a lot has happened since then. I'm currently enjoying my 3rd week of classes at Rutgers, the state university of New Jersey. I've also gotten back into the rythym of producing videos again, after a wait of almost as long as this post. Also, with Maker Faire New York, this weekend, so I am quite excited
To business. In regards to the project I started with my last entry, I went through a lot of the leg work, got the functions working, even made a tiny game. I ran into a bit of an issue thought. The program space on the Atmega328, has a limited number of write cycles that it will tolerate. Every time my little device had to switch from game to menu, it burned another cycle. Thus, I return to my original point in this argument: it's probably better to use a microprocessor and RAM, rather than a microcontroller.
Remember that oscilloscope board I said I was going to distribute but never did? Well, you probably do now. I will be releasing the files to etch your own, along with the parts sheet by next Monday, I promise.
I'm going to be doing some coverage of Maker Faire this weekend. I've set up an Imgur, for some photos, and will probably have a YouTube video or two as well.