MSP430G2553 beacon

In a former post, I developed a simple beacon code to send my ham call sign KC9TUI to a flashing LED on the Texas Instrument Stellaris development board.  It's a great device - but it has a zillion tiny pins.  Tiny pins are not practical for the homebrewer.  So, I switched over to the MSP430G2553 (a much easier-to-solder 20-pin DIP), loaded the code, and moved it to breadboard.  I'm using an LM317 and some caps to select a voltage close to 3.3, and that powers the controller.  Notice the 10k resistor which connects pin 1 (Vcc power) to the RST pin 16.  This has to be in place or the controller doesn't do a thing.  Also, please forgive my, uh, somewhat over-rated caps.  I'll get something rated to 16V for the final circuits.  These were just the first caps I found.  Without them, the noise from the power supply chip can cause havoc with the MSP430.  I take that on faith, and have not yet experimented with noisy power sources.  The final project powered with batteries will be so quiet that I'm sure it's not an issue.

Here's a quick movie so you can see the LED flashing my call sign, KC9TUI.  How's your CW?

See the video on YouTube


The final design will be to draw a PNP emitter to ground.  That's a keying circuit I use which I learned in Experimental Methods in RF Design.  If you enjoy RF electronics then you just have to have it.  The filter design software that comes with it is easily worth the price.  I've built that "1st Transmitter" three different times.  It's just a great way to start experimenting with RF transmitters.

More on the beacon project when I get it planted inside a watertight project case.  The transmitter will run from rechargeables and a solar panel, so there's plenty more work to do before this all gets soldered and mounted.