Apr 01

Open Source Microcontroller Development

uCtools is an open source collection of microprocessor programming tools. So far they support development for AVR, ARM, MSP430, STM32L1xx and are developing tools for others. If I need to develop firmware for embedded systems, this will be a handy tool to have at my disposal. For now, the arduino IDE seems like the best choice for teaching, since it is simple to use and understand. But who knows? Maybe something else will be better. You don't know unless you explore the possibilities.

Apr 01

RFduino, single chip arduino and Bluetooth

The RFduino is an arduino compatible made using the Nordic 32-bit ARM Cortex-M0 processor. The cool thing about this is that it can run arduino code and has bluetooth built in. If I can find something like this that can do RF mesh networking (or maybe bluetooth can be used, though it's usually for short range applications) so I can make wireless sensor nodes/laser tag modules that can communicate to a central hub. Just an idea.

Mar 27

Lesson Planning

I ran across the idea of recording my lessons via iPad using this tutorial (I probably want to have objects to demonstrate with, so I may want to not use an iPad). I was inspired by Salman Khan of Khan Academy (great article here about him). I can create the non-linear curriculum that I want by making the lessons cover everything that you need to know while putting links in the video to point people who want to learn more to more things (hence non-linear learning. There are many branches that you can go down in addition to learning the core material).

The whole point of non-linear learning is to capture the moment of inspiration, that time when someone is genuinely interested in a subject and wants to learn more. It is at that moment that I want to present the possibility of diving into extra material that goes above and beyond what is necessary to understand what I want people to learn. I've always wanted a course that gave me the opportunity to learn more than was necessary and explore things that I found interesting, and now I can create that for other people.

Mar 26

ATmega32U4 vs ATmega328P

I am thinking about using an ATmega32U4 instead of the ATmega328P for my laser tag project. The main advantage of the 32U would be built in USB (at the cost of built in serial hardware. Oh darn, I can use software serial. Not a big deal). The 32U is also twice as expensive. The table below summarizes the differences that matter for the laser tag project (there are many differences. I only care about the ones that my project needs. Mainly, programmability and cost; both chips have the functionality that I need).

Microprocessor ATmega32U4 ATmega328P
USB Yes No
Serial (hardware) No Yes
Price (Quantity = 1) $6.04 $3.05
Price (Quantity = 100) $3.42 $1.73
Barebones Arduino $22.95 (adafruit) $29.95 (adafruit)

But, of course, there are similarities. Both chips have 32 kB of flash memory for storing programs, and both have hardware timers, PWM and enough output for the basic laser tag game that I want to implement. Therefore, since both of these chips have these properties, this information has no effect on my decision because it does not help me distinguish which alternative is better.

Both processors are supported (can be programmed with) the arduino IDE, which makes my life a lot easier. Since the 32U doesn't need an FTDI chip for USB to serial conversion, it saves about $15 for the cost of the board. As of now, I should use the 32U instead of the 328P, since it will make the device cheaper by implementing USB communication on chip.

Dangerous Prototypes posted an article about Paperduino, an arduino Leonardo (Leonardo uses the 32U) clone. It has a cool tutorial on putting a paper label onto the board as well, which is a nice touch. For more information on the 32U4 and the Leonardo, the guys at arduino posted a great article.

Mar 22

Laser Tag Parts and Resources

Open Source laser tag already exists. Miles Tag is an open source laser tag project that has already developed open source laser tag modules. So why would I reinvent the wheel? I'm not. The purpose of my laser tag project is to teach other people how to build the units themselves and understand the science behind it.

So, here's a link to their tagging protocol. This protocol is the same as Version 2 of my laser tag project. If version 3 (serial) doesn't work, then I'll go back to this method of communication. They also have information about lenses, which is something I haven't looked into yet.

Also, their store has parts and part numbers. I may as well use standard components. Like their IR LED. I probably won't buy these parts from them, since I will most likely be able to get them from mouser, digikey or Jameco for less, but I do appreciate the effort that went into these devices. This is a great resource.

Mar 22

Spreading DIY

I want to help spread the idea that people can understand and build things. Just as Mr. Rogers fought for people's right to control when they watched his show, I also want to throw in my two cents towards helping people understand electronics. Sure, I'm not going to have the impact of Mr. Rogers, but if I can help a single person because of this, then I think I will have succeeded. Other people and companies are trying to spread the understanding of electronics, hacking (hardware hacking. Not hack into credit card database hacking), and DIY (which I find to be thrown around as a general term for doing any building-like think yourself). Here are some of them to follow, learn from and maybe partner with.

Sparkfun has a national tour where they are traveling across the country and teaching arduino classes to introduce people to electronics. Good for them.

Adafruit, as always, is spreading the science. I really like this site and what the people there are doing.

The Hacker Scouts is a non-profit similar to the Boy and Girls Scouts organizations that focus on teaching kids STEAM (Science, Technology, Engineering, Arts, Math). I'm glad to see that this is a thing for kids to do now.

Note: There are many hacker spaces, a few Maker spaces and other organizations dedicated to spreading knowledge, hacking, DIY, etc. I haven't listed those. It's an arbitrary choice.

Mar 21

Solar Panel Battery Charger Circuit

One of my problems with batteries is that they die (and that they're so dramatic. Other electronics break, but not batteries. They die. They were living, electricity feeding things that are now dead. It's sad.). There are solar charging circuits that you can buy from adafruit (note, this product is being redesigned, so the link may not work in 15-20 days from this posting, according to adafruit), which has great tutorials on how to use their products along with how it's built, but I also found another circuit at electronics-lab.com that has a solar charging circuit. I'd like to make solar powered robots, but for now I'm just buying lots of 9V and AA batteries. Going green will have to wait until time allows.

Microchip also has a solar power charging paper, which goes over the use of their chip designed for use charging batteries using solar power. Here is the article.

Mar 21

The terror of the Snooze Button

Lifehacker posted a video today by ASAP Science (they have a Youtube channel) about how the snooze button doesn't help you get any more sleep and can actually make you more tired. This adds to my convictions that the alarm clock that I make will not have a snooze button. It will wake me up, whether I want it to or not. And as the saying goes, "The me in the morning will have no respect for the me that set the alarm."