Work has begun on a code practice oscillator. There's a million and one plans for them out there, but once done I'll share my design too.
For now though, some photos (sorry, iPhone again) of the enclosure and interface. Basically, I wanted to do something different by using a simple plastic container from the supermarket. I thought a nice round one would fit the kind of thing I was after.
A basic run down of the design I have to mind (and thereby the controls on my 'enclosure' is):
- NE555 based
- Volume control
- Tone control (covering about 600Hz to 1000Hz)
- 9V battery
- Built in speaker
- Output switchable from speaker to 3.5mm socket (so that it can be easily plugged into a computer for recording and measuring of elements, as well as possible use of headphones)
- Key hooked into power line (so no on/off switch required – but concerned how this may affect oscillation, we'll see)
- A capacitor shunting the output to move from a square wave towards a sine wave
Hopefully I can get this done within the next week or so, but I'm really short on time at the moment. I'll let you know if I do. 😉