A look at the upgraded MSP430 chip shipping with the TI Launchpad

[JMN] took some time to look at the MSP430G2553 mircocontroller (translated). Specifically, he was interested in the clock options and the low power modes. This chip is one of the upgraded processors which have been shipping with the TI Launchpad.

Both the MSP430G2553 and MSP430G2452 come with the Launchpad development board. They replace the MSP430G2231 and MSP430G2211 which came with the original offering. If you already have a Launchpad the chips themselves can be had for around $2.25 and are easily programmed since the development hardware hasn’t changed.

The review starts off by looking at clock options for the processor. The internal VLO is put to the test first, with a look at the power consumption followed by temperature stability through the use of a hair dryer. The actual frequency provided has fairly low accuracy, but it stays pretty stable when hit with the hot air. The next test uses the provided 32.768 kHz clock crystal as an external input. The crystal came with the Launchpad board, and the chip has configurable internal capacitors so this is as easy as soldering the package in place. Hit the link at the top to find out how this clock source fared in testing.

[Thanks D]

Tearing down Disney’s Glow with the Show props

disneys-glow-with-the-show-teardown

[Andy’s] boss recently returned from a trip to Disneyland with a set of light-up [Mickey Mouse] ears in tow. He said that during the event, every set of “Glow with the Show” ears in the crowd changed colors in sync with the performance. After he and some co-workers speculated on how this was pulled off, [Andy’s] boss gave him a new assignment – to find out how the darned things work!

[Andy] carefully disassembled the ears, sharing his findings and speculations with us. Inside, he found a small flexible circuit board powered by three AAA batteries. At the center of the device resides a TI MSP430G2553 which is tasked with controlling the RGB LEDs embedded in the ears.

In one ear, he spotted what he believes to be a Vishay TSMP6000 IR receiver. Vishay-branded or not, he verified that it does indeed pick up IR signals using his oscilloscope and a TV remote. In the other ear, he found a pair of small IR diodes, which he speculates are used to repeat the IR timing/sync signal received in the opposite side of the device.

The synchronization methods seem completely different than those found in the Xylobands we covered a while back, so we’re really intrigued to find out more about technology behind them.

Stick around to see a video of the light show in action, and since [Andy] says he’s willing to entertain any thoughts on how Disney makes their magic happen, be sure to sound off in the comments.

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TI Launchpad adds computer control to a robot arm

[Eric Gregori] had an OWI535 toy robotic arm. Although cheap (coming it at around $30) the arm is only set up to be used via a wired control box. [Eric] knew he could do better by adding computer control via a TI Launchpad and motor driver peripheral.

The arm has shoulder, elbow, and wrist joints, a rotating base, and a gripper. All of these are actuated by 3V DC motors and have just two control wires. [Eric's] motor driver add-on for the Launchpad works great in this case. It’s got three FAN8200 dual motor driver chips on board so it can control up to six motors. Once he made the hardware connections it’s just a matter of sending the commands to the Launchpad via its USB interface, but you will also need to use a larger microcontroller than comes with the Launchpad. Here he’s chosen an MSP430G2553.

In order to make things a little bit more fun he also wrote a GUI for controlling the arm from the computer. He used RobotSee, a programming language that lets you use an image of the hardware, and overlay the controls on top of it. Now he just needs to make this into a web interface and he can have a smartphone controlled crane game.

Don’t forget to check out the video after the break. [Read more...]

Slot car lap timer/counter

For his first project using the TI Launchpad [VOJT4] built a lap timer and counter for slot cars. For us it’s always hardest to come up with the idea of what to build and we think he found a great one here.

Each time a car passes the finish line of the track it trips a reed switch that was hot glued to the underside of the track segment. Both reed switches have a capacitor to smooth out the inputs (is this acting as a hardware debounce?). The time and lap number are then pushed to a graphic LCD by the MSP430G2553.

You must be logged into the forum where [VOJT4] posted the project in order to see the images. Because of this, we’ve embedded them (including the schematic) after the break along with a demo video. But do take a look at his project thread to hear his thoughts and peruse the code he wrote.

[Read more...]