Newbie question: Making own breadboard Arduino

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1

Hi,

I have just two simple questions about making my own breadboard Arduino.
So I have bought the things I need for making such a project but at the shop they had no 16 MHz crystal oscillator, so I have bought one with 15 MHz and one with 18 MHz, can I use one of them? I guess as the Arduino book ("Arduino Workshop by John Boxall") I have just says that the oscillator determines the microcontroller's speed of operation.
And the second question I have is that in my schematic there are several cables that end up in GND, is it allowed that they are all connected to the minus pole of the battery?

I am looking forward to hear from you.

King regards,

Greenality

2

Greenality:
So I have bought the things I need for making such a project but at the shop they had no 16 MHz crystal oscillator, so I have bought one with 15 MHz and one with 18 MHz, can I use one of them? I guess as the Arduino book ("Arduino Workshop by John Boxall") I have just says that the oscillator determines the microcontroller's speed of operation.

It also determines the speed of things like the serial port. You might have problems if you want to use a bootloader.

Greenality:
And the second question I have is that in my schematic there are several cables that end up in GND, is it allowed that they are all connected to the minus pole of the battery?

Yes.

3

Gnds all need to end up connected to battery-, directly is fine. You can run a thicker buss wire around the card and connect all the Gnd leads to that using short connections.
If you're on solderless breadboard, use the outer rails for Battery + and - and make the connections to that.

15 MHz, 18MHz, that will impact the serial speed the uC talks to the PC at for downloading.
You can change the clock rate in boards.txt, it may allow communications to work ok.
Probably better off using internal 8 MHz clock instead until you can get a 16 MHz crystal for literally just tens of pennies:
~~http://www.dipmicro.com/store/XC7-16000~~
less then half a euro:
http://de.farnell.com/txc/9b-16-000meej-b/xtal-16-000mhz-18pf-hc-49s/dp/1842217

4

Hi, thanks for your anwser, so if I do not use the oscillator, do I have to worry about something else?

5

Greenality:
Hi, thanks for your anwser, so if I do not use the oscillator, do I have to worry about something else?

If you're doing this for learning/fun, go ahead. Solve the problems that appear.

If you're doing this because you're building something then you're far better off buying something like a Pro Mini.

6

Ok, I will try to fix the problems if they occur. :slight_smile: