After googling for "Sine Wave Circuit", I was delighted to find this "Arduino" sine wave circuit, because I love working with Arduino and it's compatible modules. Also, the lazer cutter used here was a wonderful discovery for me too! I didn't even know there was such a thing, but now must have one to add a professional look to the projects I sell.

However, the article has room for improvement, which is the reason for this comment. Here are my suggestions:

1. The several places the text refering to "300Ohm", and "470Ohm" need a space to make it "300 ohm" and "470 ohm, so it doesn't look like a value ten times larger than intended.

2. One schematic shows the 300 ohm resistor and cap for the low pass filter. But the other schematic omits this circuit.

3. Although the photography is very clear, no one picture shows all the wiring where it's easy to understand everything at once. Take a look at

http://1.bp.blogspot.com/-FLaRrce1svE/VFtEWeuSL0I/AAAAAAAAANI/1GbkconjhXU/s1600/bluetoothcontrol_bb.jpg

Every wire -- and where it connects -- is easy to see in one picture. And like in this picture, I always try out my projects on a white breadboard first; for it's far easier to try out alternatives and correct mistakes where all parts plug and unplug, than it is on a project board where you have already soldered the parts permanently in place.

4. The text says, "A 4.7kOhm resistor bridges pins 3 and 4 of the IC socket." Yet the schematic shows this as being a 2.2k ohm resistor. Which value is correct?

5. It would help to have a note on the pictures, explaining you can mouse-over the rectangles to pop up notes on what's inside the rectangle. I'd nearly finished the project before discovering this.

6. One such rectangle (over a straight section of wire in a schematic) says a resistor should have been here. Why not just add the resistor to the image and reload it? The note is easy to miss (and thus the need for the resistor.)

7. Another mouse-over rectangle says the color code on the resistor shown is wrong. So why not just use an art program to paint the correct colors on the resistor, and re-upload the image?

I think this is a GREAT project; exactly what I needed. But the above seven items make it hard to follow correctly. For the benefit of others, I'd LOVE to see these modifications made.