[Jordan] has been playing around with WS2812b RGB LED strips with TI’s Tiva and Stellaris Launchpads. He’s been using the SPI lines to drive data to the LED strip, but this method means the processor is spending a lot of time grabbing data from a memory location and shuffling it out the SPI output register. It’s a great opportunity to learn about the μDMA available on these chips, and to write a library that uses DMA to control larger numbers of LEDs than a SPI peripheral could handle with a naive bit of code.
DMA is a powerful tool – instead of wasting processor cycles on moving bits back and forth between memory and a peripheral, the DMA controller does the same thing all by its lonesome, freeing up the CPU to do real work. TI’s Tiva C series and Stellaris LaunchPads have a μDMA controller with 32 channels, each of which has four unique hardware peripherals it can interact with or used for DMA transfer.
[Jordan] wrote a simple library that can be used to control a chain of WS2812b LEDs using the SPI peripheral. It’s much faster than transferring bits to the SPI peripheral with the CPU, and updating the frames for the LED strip are easier; new frames of a LED animation can be called from the main loop, or the DMA can just start again, without wasting precious CPU cycles updating some LEDs.
It’s time once again for Americans to gorge themselves on hormone-laced meats covered in several sauces and gravies, all of which inexplicably contain corn syrup. It’s also Thanksgiving this Thursday, so there’s that, too. If you have a turkey defrosting somewhere, you’ve probably gone over all your cooking options – the oven, a giant propane-heated pot of peanut oil, and yes, even sous vide. [Trey] over at TI came up with a great sous vide controller using a few LaunchPad Booster packs, and surprisingly, he can even cook a turkey.
The basic idea of sous vide is to vacuum pack your protein, put it in a closely-controlled water bath, and cook it so the inside is always the same temperature as the outside. It’s delicious, and it takes a long time. We can automate that, though.
[Trey] is using a USB LaunchPad and a thermocouple BoosterPack to monitor the temperature of a water bath. A custom SSR board is wired right into the heater, and a CC3100 provides a network connection to monitor the bird. While the network may seem a bit superfluous, it’s actually a great idea; sous vide takes hours, and you really don’t dote on your warm tub of water. Being able to receive SMS alerts from a sous vide controller is actually a great idea.
With everything wired up, [Trey] tried out his recipe for deep-fried turkey porchetta. From the pictures, it looks great and according to [Trey] it was the juiciest turkey he’s ever had.
Just before the days where every high school student had a cell phone, everyone in class had a TI graphing calculator. In some ways this was better than a cell phone: If you wanted to play BlockDude instead of doing trig identities, this was much more discrete. The only downside is that the TI calculators can’t easily communicate to each other like cell phones can. [Christopher] has solved this problem with his latest project which provides Wi-Fi functionality to a TI graphing calculator, and has much greater aspirations than helping teenagers waste time in pre-calculus classes.
The boards are based around a Spark Core Wi-Fi development board which is (appropriately) built around a TI CC3000 chip and a STM32F103 microcontroller. The goal of the project is to connect the calculators directly to the Global CALCnet network without needing a separate computer as a go-between. These boards made it easy to get the original Arduino-based code modified and running on the new hardware.
After a TI-BASIC program is loaded on the graphing calculator, it is able to input the credentials for the LAN and access the internet where all kinds of great calculator resources are available through the Global CALCnet. This is a great project to make the math workhorse of the classroom even more useful to students. Or, if you’re bored with trig identities again, you can also run a port of DOOM.
In addition to all the cool boards and booster packs found at Texas Instruments’ booth at Maker Faire, the folks from 43oh.com made a showing, but not next to the TI booth. In fairness, the TI booth was right across from NASA. 43oh is cool, but not NASA cool.
[Eric], known on the 43oh forums as [spirilis] showed off a few of the neat bits and bobs developed on the forums including a lightning detector, a VFD clock, a robot, and a whole lot of blinky things. There was an astonishing array of projects and boards at the booth, covering everything from OLEDs to motor drivers.
43oh is an interesting community centered around TI’s microcontrollers, like the AVRfreaks forum built around Atmel’s offerings. 43oh has a very active forum, IRC, and a store featuring projects made by members. It was great to see these guys at the faire, and we wish more of the homespun unofficial communities would make more of a showing at cons in the future.
Sorry about the mic cutting out in the video above. There was a sea of spewing RF near the booth. If anyone has advice for a *digital* wireless mic setup, we’re all ears. This is the current rig.
There is something to be said about how easy it is to write Arduino code. For those of who you are big fans of the MSP430 and Texas Instrument’s LaunchPad series, an upcoming release of Energia brings Arduino style coding to the two newest member of the LaunchPad family: the TivaC Connected LaunchPad EK-TM4C1294XL and Wolverine FRAM LaunchPad MSP-EXP430FR5969LP.
“Energia is an open-source electronics prototyping platform … with the goal to bring the Wiring and Arduino framework to the Texas Instruments MSP430 based LaunchPad.” The newest release of Energia is exciting for the sole reason that the new TivaC Connected LaunchPad and Wolverine FRAM LaunchPad are supported. The TivaC Connected LaunchPad is a $20 development board for TI’s low-power ARM processors that has Ethernet connectivity. The MSP430 at the heart of the Wolverine FRAM LaunchPad uses up to 250x less power than flash based MCUs at low speeds in addition to many other cool benefits.
Be sure to keep an eye out for the new version of Energia, it should be arriving sometime next week. Now is a better time than ever to try out the Tiva C or the MSP430 MCUs!
TI’s LaunchPad boards have a history of being both low cost and fully featured. There’s a board for each of TI’s major processor lines, and all of them support the same “BoosterPack” interface for additional functionality. Today, TI has announced a new LaunchPad based on their new Tiva C ARM processors, which is designed for connectivity.
The Tiva C Series Connected LaunchPad is based on the TM4C129x processor family. These provide an ethernet MAC and PHY on chip, so the only external parts required are magnetics and a jack. This makes the Connected LaunchPad an easy way to hop onto ethernet and build designs that require internet connections.
This development board is focused on the “Internet of Things,” which it seems like every silicon manufacturer is focusing on nowadays. However, the real news here is a low cost board with tons of connectivity, including ethernet, two CANs, 8 UARTs, 10 I2Cs, and 4 QSPIs. This is enough IO to allow for two BoosterPack connectors that are fully independent.
For the launch, TI has partnered with Exosite to provide easy access to the LaunchPad from the internet. A pre-loaded demo application will allow you to toggle LEDs, read button states, and measure temperature over the internet using Exosite. Unlike some past LaunchPads, this one is designed for easy breadboarding, with all MCU pins broken out to a breadboard compatible header.
Finally, the price is very right. The board will be release at $19.99 USD. This is less than half the price of other ethernet-ready development boards out there. This makes it an attractive solution for hackers who want to put a device on a wired network, or need a gateway between various devices and a network.
If you’ve been coveting a piece of Texas Instruments hardware you should put in an order before September 30th. A coupon code for $25 off a purchase was posted to the Stellaris ARM Community forums and it should work until that date. Above is the overview of an order placed yesterday for two Tiva Launchpads (apparently TI has rebranded the Stellaris chips as Tiva for some odd reason). After applying the coupon code “National-1yr” the total price of [BravoV’s] order is just under one dollar (including shipping). The coupon code can be entered into a box on the right hand column of step #3 (payment) when placing an order.
UPDATE: There are now multiple comments reporting that the coupon code no longer works.
We’re pretty sure you can use this coupon code on anything in the TI store. But if you don’t have a Stellaris/Tiva Launchpad yet we highly recommend getting one. We picked ours up about a year ago. It’s a great way to try your hand at ARM programming. We have had some issues with how the breakout headers are organized — there’s some gotchas with multiple pins being connected (read the last five paragraphs of the project write up linked in this post for more). But for the price and ease of programming this will get you up and coding in no time. If you need some ideas of what to do with the board look at our posts tagged as “Stellaris”.