embedding ATMEL controller into customer board.

High guys.
I create my PCB which detect phone line signals and make some operations, and this PCB controlled by Arduino nano or Arduino Uno. All works OK.

And now I want to get just processor AT328 and embed it to my PCB to create common device.

I find the topic about bootloading here
but don't find the sample , which elements from ARDUINO NANO i need to transfer to my PCB to get minimal configuration.

So i guess to reject voltage regulator 7805, USB-TTL break 232 chip, auto switch circuit, and other.

I guess that if I keep on my PCB the
1.Atmel328 itself
2.16MHZ oscillator crystal
3.6 male pins described on picture below (D11-13,+5,GND,RESET) for initial bootloading
4.2 male pins RX,TX for sketch uploading

it give me access to bootloading and upload new version of program directly on my PCB, if I use another Arduino Uno as ISP programmer.

But I'm afraid, that I miss something or understand wrong, and would be appreciate if somebody can suggest something or point the link about subject.

6pinAVRproghead.jpg

Your list did not include the 22pf caps for the crystal, the 3 decoupling caps (Vcc, AVcc, Aref to gnd) or the pullup resistor for reset.

Unless you need the speed and precision of a crystal you may run from 8 MHz internal clock. Boatloading uses UART which may need some precision of internal clock (but maybe the internal RC oscillator is good enough). But if you are able to do ISP do you need boatloader? You still need some device in the middle to interface to USB.

If you don't need precision of ADC (or are not usig it at all) you don't need decoupling cap on Aref.

You probably don't need pull-up on reset but it cannot do harm. (It has internal pull-up, external is probably needed only in when lot of noise (long line to ISP?) may trigger it. I have no idea how much noise is needed.)

groundfungus:
Your list did not include the 22pf caps for the crystal, the 3 decoupling caps (Vcc, AVcc, Aref to gnd) or the pullup resistor for reset.

So, if I guess not use Vcc AVcc, Aref can I leave these outputs in air, (take in mind, that there are internal pull up resistor?)
Or controller will blow out if I don't put decoupling capasitors on these outputs?

If Yes, can I add the list above as

1.Atmel328 itself
2.16MHZ oscillator crystal
3.6 male pins described on picture below (D11-13,+5,GND,RESET) for initial bootloading
4.2 male pins RX,TX for sketch uploading
5.22pf caps for the crystal

Smajdalf:
Unless you need the speed and precision of a crystal you may run from 8 MHz internal clock. Boatloading uses UART which may need some precision of internal clock (but maybe the internal RC oscillator is good enough).

I can bootload the stone itself on separate dashboard, of coarse. But what the device will doing - it detect pulses with frequensy 425Hz with duty 1:1 and precision +-10%. Can it do on low frequency internal clock?
And what precision can provide the internal clock oscillator?

Smajdalf:
But if you are able to do ISP do you need boatloader? You still need some device in the middle to interface to USB.

Are You mean that if I will upload sketch over ARDUINO UNO development board, between RX and TX pins on Arduino itself and on MY NEW DETECTOR board i need not previously write down bootloader to the stone or can You explain more, please?

One habit that you should get into when developing and building custom Microprocessor based projects is to download and read the data sheets for the devices you are using.

So what does the Microprocessor data sheet say for the accuracy or precision of the internal clock ?

srnet:
So what does the Microprocessor data sheet say for the accuracy or precision of the internal clock ?

I don't know yet, but I guess same at328 as in ARDUINO UNO R3 or even ATTINY 13 or 25-85.

Just don't find internal clock precision.

So, if I guess not use Vcc AVcc, Aref can I leave these outputs in air,

Do not leave the caps off of Vcc and AVcc. They are not outputs, they are the power inputs. Those caps decouple noise from the power rails. Place them as close to the power inputs as possible.

Internal clock when calibrated for given voltage and temperature is +/- 1%.

If you use the crystal you probably need some load caps - otherwise the crystal may run on slightly different frequency, be unstable or not start at all. It depends on parasitic capacitance of your board, type of crystal and I don't know what else.
The same is true for decoupling caps on power pins. It may work without them but there may be some strange problems. It is better to put one 100nF cap between Vcc and GND and another between AVcc and GND.

You can program it with ISP - no need for bootloader. But I don't know how to do it from Arduino IDE - I either program Arduino by USB bootloader from the IDE or standalone chips by AVRDude from Atmel Studio. If you upload the bootloader via ISP you may use it to upload your sketch by connecting the standalone chip Tx and Rx (and reset) to those pins on Arduino. I have never done it so I cannot tell you more.

Yes, i does mean, is it list of 5 points is enough or need to add something more?

1.Atmel328 itself
2.16MHZ oscillator crystal
3.6 male pins described on picture below (D11-13,+5,GND,RESET) for initial bootloading
4.2 male pins RX,TX for sketch uploading
5.22pf caps for the crystal

Decoupling caps between GND and (A)Vcc.