Hello guys,
I have few questions for you and I'd be really grateful if someone could answer them
I've been programming arduino for few months and I know all the basics. I even started my small little project and few friends are interested in buying it. So I decided to pay some company to make me couple of PCBs according to my schematics. I don't really want to solder all these LEDs, resistors, etc. every time, so making a custom PCB with ATmega and my components seems pretty reasonable.
My project is based on Arduino Pro Mini, so I had to base the schematics on it.
And now the questions:
Here are the Pro Mini schematics. U2 is a voltage regulator, but what about other elements (JP1, JP2, JP7)? What are they? And also, are all of the connections necessary on the ATmega? I think resonator (PB6 and PB7) is necessary, but what about all the others? Do I have to connect reset to DTR and have all these capacitors and resistors? What is AREF pin and why is it connected to GND, and why through a capacitor (C1)? Why there's VCC connected to GND through a capacitor (C3), on the bottom left from the ATmega? What does it mean and is it even necessary? I'm a little bit lost in all these information, but I'm trying as hard as I can to understand all of this.
And now about programming ATmega:
So far I've been programming Arduino using IDE, and sending the code using TX, RX and RST pins. I've been doing some researches and here is what I managed to understand: I won't have an arduino bootloader on the ATmega bought in a shop, so I need to send the program differently. I need USB or LPT programmer and connect it to RST, MOSI (D11), SCK (D13), MISO (D12) and GND on the ATmega. I also need application which would send hex file (compiled for ATmega168, which I'm going to use*) to my ATmega, like this one http://dybkowski.net/content/en/node/15
I'm going to make my own programmer through LPT port and connect specific LPT pins directly to ATmega pins (14 > RESET; 16 > MOSI; 17 > SCK; 10 > MISO; 25 > GND). My computer is not equipped with LPT port, and I'm going to use standard LPT > USB converter. Won't this cause any problems?
Are all these information correct? Does it work that way or I misunderstood something? Is that application (link above) good for sending programs to ATmega? Please correct me if I wrote something wrong
*I know Pro Mini uses ATmega328 now, but 168 is cheaper and will work just fine with my project.
Sorry for my English.
P.S. The only elements on arduino are ATmega, resonator, voltage regulator, resistors, capacitors and LEDs, right? Or are there any others?