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Welcome to Cemetech! Since 2000, Cemetech (pronounced KE'me'tek) has been teaching programming and electronics and developing software and hardware. Among Cemetech's specialties are TI, HP, and Casio graphing calculators like the TI-84 Plus, TI-Nspire, HP Prime, and Casio Prizm, embedded and DIY electronics, and computer and web programming. Cemetech provides a safe, friendly space for people to learn, show off projects, and share knowledge and expertise. Our staff of friendly volunteers hang out on our forum and IRC and SAX chatrooms, and are happy to help.
Projects of the Month: September 2016
Published by tifreak8x on October 17, 2016 at 4:35:02 PM CST | Discuss this article (3)

Hello again, everyone! Another month (and a little more) has passed since our last PotM post, and this past month we've had quite the list of projects that was worked on.

  • Endless RPG: Battlesquid released a new version of his game, fixing bugs and adding improvements to the game. Check the link to the topic for the download link.

  • CalcTalk: Kydapoot has been working on a Siri like program for the 83+ line of calculators, offering up a variety of features to make the program useful. He has plans for some more advanced things, so check out his topic and let him know your thoughts and possible feature requests.

  • Atomas: For those playing with Atomas, you'll want to check out this thread. An update was pushed to remedy some issues regarding the game that affected displaying of certain atoms and the high score feature.

  • Escheron: Twilight over Ragnoth: Iambian has done more work on his toolchain and game, changing up the font and doing other work. Check out the topic for some awesome screenshots and a more technical explanation of what was done.

  • Action Battle: Another project by Kydapoot, where you fight an onslaught of enemies. He has a long list of feature and wants, check out the thread if this project interests you!

  • Doodle Jump CE: Unicorn has started working on a Doodle Jump game for the CE and has gotten a nice title screen done. He's currently fighting with school related life, so keep an eye on this project for future updates when he has them.

  • Reuben Quest 3: Sorunome has brought this project back into the spotlight, and boy does he have some awesome progress to show! A lot of his updates now revolve around story and map data entry, which is a bit harder to show screenshots for. Check out the thread for all the awesome that this project is taking on!

  • Text File CE: This is a planned future text editor with a number of options by seanlego23. His first post shows his plan of attack for this project, which looks like this text editor will have a good list of features for students to use. Check out the topic and let him know what you think of his current progress!

  • ConvPNG: If you've missed it, MateoConLechuga has posted up an update for this project, to assist with compression things. Check out the topic for a link to an updated version.

  • Pac-Man CE: MateoConLechuga has cleaned up and optimized his Pac-Man game, and added in a new version where you can access a new map. Check the topic for a link to a screenshot and download link!

  • Chess CE: MateoConLechuga has posted up some updates regarding his Chess game for the CE, stating he has upgraded the engine to something smaller, updated the graphics, and numerous other things. Check out the link for a download and screenshot!

  • CE C SDK and libraries: MateoConLechuga and jacobly have worked on and done some fixing to the C SDK and libraries. There were a lot of updates done, so check out the topic to see all that's been accomplished!

  • ICE Compiler: PT_ has been hard at work on this project, adding in and showing off so many things, it's too numerous to begin to mention here in this section. Start at the link provided and dive into all the features PT_ has provided for this project, I'm sure you'll be impressed!

  • Claw Embedded Development System: Muessigb has completed the assembler for his new development system for embedded devices, and requests help testing it. Claw is essentially a VM with a custom assembly language that aims to run on a variety of platforms, from Atmega devices like the Arduino up to 64-bit PCs. If you're interested in giving it a try, head over to the topic, give Muessigb your feedback, and test out the assembler!

  • CEmu: Since pimathbrainiac is no longer maintaining his CEmu build server, jacobly has put together his own build server for nightly CEmu builds, for those too lazy or inexperienced to build CEmu from source. The CEmu team has also been working on improving the CEmu keypad, fixing bugs, and improving variables transfers.

I apologize to everyone on the delay of this being posted. There were a couple that I didn't feel I could properly write bits for, so Kerm managed to get them written for me when he found a few spare minutes to do so. Make sure to send him some love!

And as always, we thank our contributors for making these projects and keeping us updated! Until next month, keep them projects coming!

Cemetech at World Maker Faire 2016 Recap
Published by KermMartian on October 8, 2016 at 1:09:35 AM CST | Discuss this article (6)

For the fifth year in a row, Cemetech spent last weekend at World Maker Faire in New York City, showing off the value of learning programming and electronics with graphing calculators. Since 2012, we have been going to the Faire to display hardware and software projects, talk to kids, their parents, teachers, and the general public, and generally just to enjoy a weekend outside. Two weeks ago, we announced that we'd be at the Faire for a fifth year, after over three months of planning what we would show at Maker Faire. Like last year, we heavily focused our message on the fact that programming (and electronics) are vital skills to have, even if you don't go into STEM fields, and that graphing calculators are the perfect way to get started. Many of you have heard my spiel too many times already:

Graphing calculators are an ideal platform on which to learn programming, because most high school students in the US already have them, carry them around in school and commuting, and can whip them out to work on their latest projects. You don't need to download, install, or configure anything; just hit [PRGM] on most graphing calculators, and you can instantly start writing TI-BASIC (or a similar language) directly on the device. You don't have to worry about breaking the calculator: make a mistake, and it'll probably help you find where you made a mistake, and what you did wrong. Calculator programming adds an element of competition, and has done so before the term "social media" had even been coined: you can send your programs to your friends' calculators, get the prestige of having created a cool program or game from scratch, and look at how things other people made work. Finally, as you get more advanced, you can advance to a more complex language like C or ASM that lets you go even deeper into concepts like computer science and computer architecture, or even electrical engineering.

This year, we ended up showing off a variety of projects to make these points; from left to right along our table:
  • Whack-a-Mole: Built with a TI-84 Plus C Silver Edition, a TI MSP432 Launchpad, and lots of RGB LEDs and light sensors, the Whack-a-Mole project was a hit at World Maker Faire 2015 and T^3 2016.
  • CALCnet Networking Demo: Four TI-83 Plus calculators connected via CALCnet, running the Flourish demo, showing how you can build and test a complex communication protocol with just the hardware your calculators provide, plus a few wires.
  • GPS Demo: A version of the GPS for graphing calculators project, allowing a calculator to communicate with a GPS module to get its latitude, longitude, altitude, the current time, and more.
  • SimpleI/O Demo: First displayed this year at T^3 2016, the SimpleI/O demo illustrates how easy it is to connect an Arduino to a graphing calculator. It shows how a calculator can read the state of pins on an Arduino to see if you're pressing a button or toggling a switch, and how the calculator can in turn control LEDs, motors, and more.
  • Sound Demo: A TI-84 Plus Silver Edition with mobileTunes and songs by Alec "qazz42" Szigeti and Thomas "elfprince13" Dickerson, plus my floppy drive music with a TI-83 Plus project.
  • Interactive calculators for games: a TI-84 Plus CE, TI-84 Plus C Silver Edition, TI-84 Plus Silver Edition, and if any of them are still working, a Casio Prizm, with games and other programs loaded.
  • "Using the TI-84 Plus" and "Programming the TI-83 Plus/TI-84 Plus": As has become traditional, we brought copies of my books as examples of written reference material that new learners could explore outside of Cemetech. "Programming the TI-83 Plus/TI-84 Plus" teaches programming concepts to beginners via TI graphing calculators, giving them a toolbox of programming knowledge they can bring to any programming language. "Using the TI-84 Plus" is the missing manual: a gentle guide to the vast array of math and science features available on TI graphing calculators, grounded in plenty of examples just like the ones students might see in class or on the SATs.
  • Learn to Program demo: A giant calculator emulator, with key entry from a real TI-84 Plus C Silver Edition calculator. Aims to teach visitors to write a simple guessing game in 60 seconds.
Unfortunately, although we wanted to display the TI-84 Plus Calculator Electrocardiogram (ECG) project I've recently been working on, it wasn't ready in time for the Faire.

All of this year's volunteers at the Cemetech booth were veterans of at least three World Maker Faires. From left to right above, our booth was manned by Nathaniel "Eeems" van Diepen, also an administrator on Omnimaga, Tim "geekboy1011" Keller, Cemetech global moderator, community liason, and Omnimaga jack-of-all-trades, Alec "qazz42" Szigeti, loyal Cemetechian who has attended every single Maker Faire with us, and head honcho Dr. Christopher "Kerm Martian" Mitchell, founder and administrator of Cemetech and yours truly. Everyone pitched in wholeheartedly, whether talking to the thousands of visitors who stopped by our tables to explain Cemetech's mission and why we were at the Faire, keeping our demos running, or protecting the interactive calculators from the destructive hands of small children. We combined exhausting 10am-6pm days at the Faire (more like 8am to 8pm with travel, setup, and teardown) with our annual traditions of socialization, dinners, and enjoying each other's in-person company. As always, most of us also stopped by Maker Faire on Friday night to start setting up, get paella, beverages, and tasty desserts, and start setting up our booth.

By the end of the weekend of October 1-2, 2016, we had given away all of our Cemetech bookmarks (a first for us!), worn out our voices, and explained graphing calculators to visitors young and old. Most importantly, we left satisfied that we had opened many more eyes about the value of exploring programming and electronics with calculators, and excited to see some of our more enthusiastic visitors again here on Cemetech.

My heartfelt thanks to everyone who helped make our fifth World Maker Faire appearance a resounding success, especially Tim, Nathaniel, and Alec who joined me for two long days of telling students, teachers, parents, professionals, and the general public why they should learn programming and electronics with their graphing calculators. The encouragement of everyone here on Cemetech was a big help as well, and several of you stepped up and offered to share the burden of preparing for the Faire. I hope that we'll see as many of you as possible as attendees at the Faire next fall, and if you're interested in helping staff the table, please speak up!

Cemetech Going to World Maker Faire 2016 for 5th Year
Published by KermMartian on September 26, 2016 at 12:17:41 PM CST | Discuss this article (7)

For the past four years (2012 recap, 2013 recap, 2014 recap, 2015 recap), Cemetech has been showing off programming and hardware hacking with graphing calculators at World Maker Faire in New York City. This September, we'll be reprising our role once more, presenting our latest programming instruction and hardware hacks at World Maker Faire 2016. Held in Flushing Meadow Park next to the New York Hall of Science the weekend of October 1st and 2nd, the Faire will hold the latest and greatest in DIY hacking. This will be the Faire's seventh year, and each year that we've attended, it has grown in popularity, attendance, and most importantly, the quality and variety of projects displayed. We have been brainstorming our plans for the Faire, and our team has begun building the various displays we'll need for the occasion. We hope you'll come visit our booth if you're in New York at the beginning of October, and with less than a week left until the Faire, we have our work cut out for us to complete our preparations.

Among the many things we plan to display this year at Maker Faire:
  • GPS demo: A hacked-up version of the GPS for graphing calculators project.
  • Game Boy camera demo: The Gameboy camera + TI-84 Plus C Silver Edition project, properly calibrated for sunlight.
  • Whack-a-Mole: Built with a TI-84 Plus C Silver Edition, a TI MSP432 Launchpad, and lots of RGB LEDs and light sensors, the Whack-a-Mole project was a hit at World Maker Faire 2015 and T^3 2016.
  • Learn to Program demo: A giant calculator emulator, with key entry from a real TI-84 Plus C Silver Edition calculator. Aims to teach visitors to write a simple guessing game in 60 seconds.
  • Simplified networking demo: four TI-83 Plus calculators connected via CALCnet, running the Flourish demo.
  • Interactive calculators for games: a TI-84 Plus CE, TI-84 Plus C Silver Edition, TI-84 Plus Silver Edition, and if any of them are still working, a Casio Prizm, with games and other programs loaded.
  • Sound demo: A TI-84 Plus Silver Edition with mobileTunes and songs by Alec "qazz42" Szigeti and Thomas "elfprince13" Dickerson, plus my floppy drive music with a TI-83 Plus project.
  • Calculator ECG: An ECG built with an Arduino and a TI-84 Plus C Silver Edition, and if time permits, the TI-Innovator Hub.

We look forward to seeing you at the Faire, or if you can't make it this year, to bringing you updates here on Cemetech, on our Twitter feed, and on our Facebook page.

More Information
General World Maker Faire 2016 information

A selection of photos from our booth in 2015.

Hands-On with the TI-Innovator
Published by merthsoft on September 20, 2016 at 7:27:36 PM CST | Discuss this article (15)

Last week I found a TI-Innovatorô Bundle for sale and figured I'd pick it up to play with it. I wanted to post my thoughts on this device as a programmer, and as a TI calculator enthusiast. If you're not familiar with the TI-Innovator, it's a box containing a TI MSP432 Launchpad development board, loaded with a custom firmware, that you can connect to your calculator. The upshot is that it's an educator-friendly way to teach students about coding and electronics, something of a more formal version of our popular ArTICL library to explore electronics projects with Arduinos and TI calculators. It consists of the TI-Innovator hub itself, connected to your TI-84 Plus CE or TI-Nspire CX calculator, and can be expanded with two accessory kits from TI. The I/O Module Pack contains a servo, vibration motor, light sensor, and white LED for TI's "Science Through Engineering Design" activities, while the Breadboard Pack contains discrete electronic components and a breadboard for the Path to STEM Projects activities.

I will say, right out of the box, it's a very nice looking device. It's fairly a fairly straight-forward process to get started with. I updated the software on my CE, installed the app, plugged it in, and wrote a quick blinking program:
Wait 1
Wait 1

And, viola, a blinking light!

I will say, right out of the box, this is a joy to program. One of the things I love about programming calcs is the ease of getting in to it. There's a simple menu interface so you don't need to remember every keyword, and it's easy to just explore and make something happen. This holds true for the Innovator Hub, as well. I knew right away that this would be a great way to get kids to play with electronics and learn how to program.

After the blinking light, I wanted to do something a little more complex. I had a lot of things I could play with with the bundle, but wanted to keep it just using the Hub for now. So, the next thing I figured I'd do was make some sound. This is where I ran into my first error, and boy does the hub let you know something went wrong:

The problem was I was doing Send("SET SOUND F to try to send a sound of frequency F. This doesn't work--it doesn't know about the variables on the calculator. This was fixed with Send("SET SOUND eval(F. And I had a chromatic scale playing:
Send("SET SOUND eval(F

Again, I found this great fun. I noticed when playing the music, that the RBG LED was blinking, and then made a little program to cycle between the lights. At first I thought there would be many colors, but I think that each can only be on or off. This is where I learned that you can use 0 for off and 1 for on. This makes programming a little easier when you're doing on and off programmatically. I don't have a video of that, because it's not terribly exciting. Note: I have since learned from this page that you can do more with the on-board RGB LED. The lesson here: Always read docs.

However, this made me want to play with the RGB LED that comes with the breadboard kit. This reminded me why I didn't pursue electronics any further in my studies: I dislike dealing with and hooking up all these components. I got it all hooked up, but will admit that I couldn't figure out how to program it. It would be nice if the instructions booklet had more details on how to do things. That said, I decided instead to make a counter using the seven segment display.

The display that comes with the bundle is an LTS-4301JR. I looked up the datasheet to hook it up, and again couldn't figure out the code. That's when I found this page which has lots of useful information for hooking up these kits, and I got it working.

At this point I had had enough with electronics components and breadboards, so I figured I'd play with some of the other kits that came in the bundle. The range finder seemed like it would be fun, so I made a little program that translated range to frequency, and made a little fake Theremin:

Overall, I have to say I'm quite impressed with this. Out of the box, with just the hub, you can do some pretty fun things. I wish the Hub itself had some built-in inputs--maybe the buttons on the board can be read from the calc if you take off the cover. I'd like to experiment more with the built-in stuff. There are some buttons and some jumpers.

Having simple inputs and outputs is really nice for getting people up and running with some fund things right away, and having the more complicated breadboard stuff makes it so you can basically do anything with the calculator driving. I think this is a great way to get kids into programming, and I look forward to seeing what teachers and TI do with it in the future! If you have any questions about using the TI-Innovator or want us to try some experiments with ours, please don't hesitate to ask.