Rekam1 is a rapid prototyping virtual machine written in Energia which enables rapid prototyping with your smartphone. This platform is designed to accelerate the development of three types of applications:
Sensor Controlled Actuators (temperature/light/etc. controlled doors/lights/motors/gadgets)
Smartphone Controlled Actuators (speech/accelerometer/UI controlled doors/lights/motors/gadgets)
Sensor Controlled Smartphones (temperature/light/etc. alerts/logging on your phone)
In this blog we’re going to talk about a smartphone controlled actuator application recently demoed an World Maker Faire: the “Rekam1 Clay Thrower” and how Energia rekam1 code was used to enable this.
The Clay Thrower uses a speech or UI push button trigger to sling clays hundreds of feet into space. It does this through a solenoid. Because the solenoid draws 2.5 Amps of current, a power FET is connected to the MSP430 to energize the launch.
Power FETs have a drain, gate, and source. The source pin in this example is connected to ground(GND) while the gate pin is connected to pin 19 of the micro-controller. The drain pin is connected to one terminal of the solenoid and the other pin is connected to the positive terminal of a LIPO battery I’m using. In this example, rekam1 is used as a “command interpreter”. This means it immediately executes whatever command it receives over the UART. If you are using an MSP430G2553 Launchpad, you can see in the picture below how you would connect your board.
You can find the rekam1 sketch in Energia under File->Examples->Communications->rekam1. In order to build rekam1 for this platform, simply comment out the #define for G2553 and comment the Wi-Fi include lines and CCX #define as shown below. Ensure you’re building for the MSP430G2553 and hit the build button.
When you connect a battery, Power FET, and solenoid to your Launchpad, your setup should look like below. You can now activate and deactivate your solenoid through a serial port window inside energia by simply typing: put 19 100 and put 19 0 a second or so later. Make sure that you have setup your terminal window to 9600bps with a new line sent when you hit the “send” button.
In the video below, you can see how fun this little gadget can be. In this case, we used google speech recognition and a simple “pull” button in Android to send these two commands. If you’re interested in learning more about how to use rekam1, you can visit my blog at rekam1.blogspot.com<http://rekam1.blogspot.com/>