Under $30.
Easy to put together.
You have no excuse not to build this.
This is a 1-54MHz signal generator that uses an AD9850 DDS synthesizer that's controlled by an Arduino.
The ebay market is currently saturated with some useful and inexpensive electronic assemblies. The real advantage to using these assemblies for experimentation is someone else has taken care of the time-consuming tasks for you. You don't need to design/etch/silkscreen a PC board, take care of power conditioning or solder on support components.
You just need to connect the modules together, add a microcontroller and start doing something interesting.
If you're not into writing code, fortunately the internet has a bunch of other folks who've blazed some trails, read the datasheets and written sample code. This means that once you've tied the modules together you have someone else's code to either use as-is, or as a jump-off point for making your own changes.
An example of a simple project is a signal generator using an Analog Devices AD9850 DDS synthesizer controlled by an Arduino with a 2x16 display, encoder and 5-way pushbutton.
I ordered the parts for this on ebay from 'nyplatform', received them within five days and built it in an evening. This particular company ships from US locations. Many other companies ship directly from China and my experience has been positive with all of them.
Parts and cost breakdown:
- LCD Key Rotary Encoder function Shield - 10.38
- AD9850 - 7.36
- Arduino UNO R3 Development Board - 8.96
- shipping - 1.99
Ignore the Hammond project box -- you can do without it. The scope of my 'next' project happened to grow beyond this box -- so it's just for the signal generator.
The code that I used is written by AD7C and featured on his webpage. The code only needed very minimal changes to suit the pins that my shield is using and to work around reset on the AD9850 being tied to ground.
Turn the knob to tune. Push the button to change the tuning step.
What can you do with this?
Ever needed a signal to test something on a receiver but didn't want 100 watts from your existing HF radio? Need a low-level signal to trace a circuit? Replace a VFO on an older radio with something digital? A jump-off point for to design a CW or PSK beacon? Use the square wave output to generate some harmonics for higher frequencies?
You're seriously only limited by your own ambition.
This page last modified Fri Oct 24 16:15:05 CDT 2014 by timc!