I'm planning on building the $50 robot or a sandwich bot, but I have some questions about parts.
First, I should start off explaining that I am living in South Korea. So, my options for parts are somewhat limited. Not because they don't exist here (I'm sure they do considering all the electronics leaving this country), but because I don't speak Korean well enough to find everything. I spent some time trying to find stuff on websites with only Korean, and it was stressful, to say the least. Of course I could have stuff shipped from overseas, but I'd like that to be last resort. I've found a site that has most of its parts listed in English, which is great. However, they seem to be lacking the resistors listed in the $50 robot.
According to the parts list, you should have 340 ohm and 1.62K ohm resistors. The site I have found (ic114.com) doesn't have either. Near fits they have are 330, 390 and 1.8K ohm in both 1/4 and 1/2 watts, and 1.6K ohm in 1/2 watts. Would 330/1.6K ohm or 390/1.8K ohm be acceptable substitutes? I think they would be looking at the schematic, but want to be sure. They're just for the LED and photo resistors, right?
The 220uF+ electrolytic capacitor. This could be an aluminum capacitor, is that correct?
I could get photo resistors that are .5, 1.0 or 1.5 cm. What is the difference besides price?
What are the dimensions of the atmega 8? I saw two possible sizes for 28 pin DIP sockets, wide and narrow, but didn't know which to pick. For the future, does anyone know of a roundup or comparison of all or most of the atmega micro controllers?
And finally, if I add capacitors to my motors, exactly what value and type of capacitor would be appropriate? If I build a sandwich, I'll probably use tamiya gearboxes since they're so cheap.
Thanks everybody! I hope this isn't too many questions at once!