I have some doubts regarding ISP, Bootloaders, and so on.
Situation: As a teacher I want after a project is done on an Arduino to make a custom PCB out of each Project. I want to be able to upload the sketches to a blank ATMEGA328, and then make custom pcbs using those ATMEGAS.
I have an arduino UNO I want to use as a HOST and using this protoshiled and a ZIF socket.
THis is the ZIF socket
Proto Shield
I am a bit confused if I need to have a circuit with a crystal or not.
And also if I need to leave my atmega328 chip in the host or not.
Also, after I succesfully make a custom atmega328, and I want to make a new PCB, are there some components I should also take into account for the microntroller to work? (Reset buttons, Resistors, capacitors...) (I will be adding my specifics for the circuits built on)
I use this as the starting point for any Uno derivative design, see the bottom left (or right) half of this schematic - it's basically an Uno less the USB/Serial interface.
If your boards have the same, then you use the ICSP header and bootload it as if it were an Uno (simple choice right? every board programs like an Uno) then connect an off-board USB/Serial adapter for downloading sketches via the serial port if you want.
Then use Nick Gammon's bootload installer sketch running or your Uno to install the bootloader.
Arduino as ISP works fine just you have to carefully read and prepare the circuit according the instructions, no doubts.
I am a bit confused if I need to have a circuit with a crystal or not.
You need not crystal for the raw chip because it's set for internal clock source use by default from the manufacture. However, during the first burn of bootloader, the settings are changed to external clock source use (Arduino required this). Since this moment you have to use a crystal.
And also if I need to leave my atmega328 chip in the host or not.
Of course, ISP program have to run somewhere.
Also, after I succesfully make a custom atmega328, and I want to make a new PCB, are there some components I should also take into account for the microntroller to work? (Reset buttons, Resistors, capacitors...) (I will be adding my specifics for the circuits built on).
Just read the instructions for Arduino as ISP here on the web. There is also about the minimal board or as CrossRoads mentioned the Nick Gammon's tutorial is pretty useful.
