Raspberry Pi, BeagleBone, Arduino, UDOO — all names we’re familiar with when it comes to development boards or single-board computers (SBCs) used in maker/DIY projects. Texas Instruments on the other hand… Calculators are the first thing that comes to mind. After that, they’re widely known for their semiconductors, analog chips, and last but not least microcontrollers.
Unlike the popular boards listed above, TI’s development boards aren’t as widely adopted for projects on the massive scale. That doesn’t mean they are any less of an effective board, in fact they can hold their own against the others depending on the task. The company’s Tiva-C LaunchPad series (TI’s wiki on them here) is a pretty impressive board for its size and features an ARM Cortex-M4F SoC with up to 1Mb of Flash memory for storage and up to 256Kb of RAM depending on the model. In this mini roundup, we will take a look at some of the interesting projects makers have designed using TI’s new board. Even I made a project with the Tiva-C… more on that in a bit.
First up, Instructables user RegioAlpha combined a HEBUG Scarab XL with a Tiva-C Launchpad (version- EK-TM4C123GXL), giving it a level of autonomy while still retaining its RC capabilities. The Scarab itself is driven by a pair of servomotors that drive the robots six legs with 7-way steering, which is driven by an internal control board. RegioAlpha retained most all of the internals but rerouted the servomotors to the LaunchPad, essentially bypassing the Scarab XL’s internal control board and moving the RC and control functions over to the Pad.
RegioAlpha then programmed the robot using Keil’s µVision IDE to give the robot basic autonomous movement (forward, backward, etc.) and powered it using a pair of cellphone batteries. His Scarab XL robot is still a work in progress and he plans to add sensors to give it increased functionality and autonomy. See more at their Instructables page.
Next up is a sound tracking device that can locate a target based on its distinct sound using cheap off the shelf parts. Designed by Graham Chow, his Acoustic Localization tracking device features a pair of microphones connected to a pair of max9812 chips (providing a fixed gain of 20dB) to grab nearby sound. The sound is then passed through an analog low-pass filter Graham designed using a breadboard and cheap ceramic capacitors, which helps eliminate some of the electrical and mechanical noise created by the LED target locator that’s actuated by a servomotor.
Additional digital filtering is done using the Tiva-C’s (version TM4C123GH6PM) onboard ADCs (8-channels total), after which the signal data is sent to a laptop for correlation. The whole kit is mounted to a length of board with the microphones positioned at either end in order to get a more precise location. Once the signal is received, it then sends the signal data to an LED aimer that points to the target actuated by a servomotor. Graham designed customized correlation software using C++ and C# along with Windows 10. It’s not precise but it is accurate out to a certain distance. More at their project site.
It may not look like much but Selcuk Cakmak’s Tiva LaunchPad: Internet of Things project has some potential. Selcuk essentially designed a simple way to remotely control IoT devices, in this case a simple servomotor using the Tiva-C (version EK-TM4C123GXL) paired with an ESP8226 Wi-Fi module.
The Tiva-C and connected devices act as the client while a laptop or desktop PC acts as the server and the ESP8266 acts as the link between the two (via TCP). Selcuk programmed the setup using Java for the server side and Code Composer Studio for the client — simple enough. Code of his Tiva IoT project as well as a walkthrough of his build can be found found here.
Simple Traffic Light System
This entry in this mini roundup is aimed at novices just getting to know the Tiva-C and are taking their first steps into the DIY world using SBCs. Pavan Tripathi’s Traffic_Lights project uses the Tiva-C (version EK-TM4C123GXL) to emulate the function of traffic lights using eight different colored LEDs (signifying West, South and Walk).
His design is a simple circuit that uses three button switches to emulate the sensors found on real lights, which are laid-out on a breadboard. Pavan coded his build using Code Composer Studio, which he presents in easy to follow steps, which can be found here.
I actually designed my own project using the Tiva-C (EK-TM4C123GXL), and an ADXL335 accelerometer, that helped improve video camera stabilization while moving around. Instead of software based stabilization, I wanted to try out active-mechanical stabilization using the gyroscope effect. You know… that experiment with the spinning bicycle wheel you couldn’t move back in 8th grade science class.
For the gyros, I machined a pair of spindles and attached them to DC motors that activate when the pitch of the accelerometer changes to a level setting. Pointing the camera down turns the motors off since it is probably not in use pointed at the floor.) The Tiva-C monitors the information from the sensor and engages the motor once the tilt threshold is triggered. For more information and a complete walkthrough of my build, head to element14 after this link. The Tiva-C needs more love… I hope this list help inspire.