Hi ! I'm working on a DIY Weller RT soldering station project, based on the work done by Matthias Wagner :
His original design uses an Arduino Pro Mini (5V, 16MHz), which features an [u]Atmega328-AU[/u]. I'm working on implementing the project on a single PCB with the same chip (the TQFP package) which I will solder myself (I'm essentially getting rid of the Arduino board).
Therefore, I'm trying to figure out how to burn a bootloader and program the chip. If I'm right the bootloader can be burned through ICSP with an Arduino UNO (which I own) and then the chip can be programmed through FTDI like the Arduino Pro Mini.
Now I have questions. I know they have been discussed before on this very forum and elsewhere, but it seems that there is no definitive answer...
The program has been written for an [u]Atmega328-AU[/u], I'm wondering if I could use an [u]Atmega328*P*-AU[/u] instead, which has lower power consumption (again, correct me if I'm wrong here).
The [u]Atmega328-AU[/u] and [u]Atmega328*P-AU[/u] have two extra ADC pins compared to the **DIP-packaged versions. When burning the bootloader on the chip, what board should I choose in the Arduino IDE board list for the [u]Atmega328-AU[/u] and the [u]Atmega328P-AU[/u] respectively, to make sure that the 2 extra ADC pins become functional ? As an example if I burn the UNO ([u]Atmega328P-PU[/u] **DIP* which doesn't have the extra ADC pins) bootloader in an [u]Atmega328*P-AU/u, will the Arduino IDE allow me to use the two extra ADC pins offered by the **TQFP* version ?
Do I really have to burn the bootloader through ICSP and then send my program to the chip through FTDI ? Is there a cheap solution requiring less pins ? Because when designing my PCB, I would like to avoid having to place 6 pads for ICSP and another 6 pads for FTDI, my PCB would get a little bit messier and I'd rather avoid having to route an extra 12 traces...
I will really appreciate any help you can provide :)