Arduino Uno chip on breadboard

Using Arduino Project Guidance
1

Hey guys,

For the past 2 days i've been looking on how to use the chip from my arduino Uno on a breadboard. No success, so far :~

Here's the deal: I have an arduino Uno, i just want to see the chip working on the breadboard. Since i dont have any capacitors, 16Mhz crystal and stuff, I want the minimal thing.

Question 1: Since I took the chip from my arduino, there's no need to burn a bootloader in it, right?

Question 2: Can't I just upload my sketch while the chip is in the arduino, transfer the chip to the breadboard, connect the +5v and ground in the chip (pins 6, 7, 19 and 21) and have my sketch running?

It's a simple sketch. Just a digitalWrite(12, HIGH) to light up a LED. And, of course, beside the +5v and gnd mentioned above, I connected digital pin 12 to the led.

thanks

2
  1. Yes
  2. Yes, but: When you take the controller from the Arduino it requires 2-Cap 22pF and 16MHz xtal.

This may help so: http://www.gammon.com.au/forum/?id=11637

3

BrunoZumba:
Hey guys,

For the past 2 days i've been looking on how to use the chip from my arduino Uno on a breadboard. No success, so far :~

Here's the deal: I have an arduino Uno, i just want to see the chip working on the breadboard. Since i dont have any capacitors, 16Mhz crystal and stuff, I want the minimal thing.

Question 1: Since I took the chip from my arduino, there's no need to burn a bootloader in it, right?

Correct, the bootloader is already burn in and protected in flash memory.

Question 2: Can't I just upload my sketch while the chip is in the arduino, transfer the chip to the breadboard, connect the +5v and ground in the chip (pins 6, 7, 19 and 21) and have my sketch running?

You forgot about the external clock source required to operate the chip, as it has it's fuse bytes burned when it's bootloader was installed to only utilize an 16Mhz external clock resonator (2 pin crystal + 2 caps or one 3 pin ceramic resonator) to operate the chip. Also there is usually a need for a pull up resistor for the reset pin and a couple of .1ufd caps wired to Vcc and Avcc pins to ground. A same size cap is recommended from Aref pin to ground if you are going to use the analog input pins.

It's a simple sketch. Just a digitalWrite(12, HIGH) to light up a LED. And, of course, beside the +5v and gnd mentioned above, I connected digital pin 12 to the led.

thanks

4

Huuuummm... okay.

So, as my chip already has a bootloader from arduino Uno, it needs the capacitors, the crystal, etc, right??

If i buy a new atmega328 chip that has no bootloader in it i'll be able to burn a bootloader that doesn't need those things and can run on a minimal configuration, using only the 8Mhz built-in oscilator from atmega328?

5

yes