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Topic: Burning bootloader on Atmega328 with an Arduino UNO Rev3 (Read 49 times) previous topic - next topic

geratheg

So I want to burn a bootloader using the Arduino UNO Rev3 as ISP and the target on a breadboard.

Following this tutorial: http://www.arduino.cc/en/Tutorial/ArduinoISP

They say to put a 10uF capacitor between reset and ground if using an Arduino Uno as an ISP. I have an Arduino UNO R3 which I want to use as an ISP to burn the booatloader.

However, I don't quite understand whether the 10uF capacitor goes on the Arduino UNO (source) reset pin (next to 3.3V pin) and ground or does it go on the breadboard (target) reset pin on the Atmega chip in the corner and ground?

One more question:
Since my Atmega is soldered onto a board, I have the AREF and AVCC pins both connected to +5V.
In the diagram in the tutorial, only the AVCC is connected to +5V. Would I be able to program it following that tutorial with the AREF also connected to +5V, or does it have to be wired like in that tutorial where AREF is not connected to +5V?

Attached is a picture of the pinout I'm referring to so you know which pins I'm talking about.

Thank you!

CrossRoads

Use Nick Gammon's bootload installer sketch instead, no fooling with 10uF caps needed to try and keep the Arduino in reset for some length if time.

http://www.gammon.com.au/breadboard
or
http://www.gammon.com.au/bootloader

5V on Aref screws you up if you want to use the internal 1.1V reference, see Figure 24-1 of the datasheet.
You should only have a 0.1uF cap from Aref to Gnd.
It will not impact programming.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

geratheg

So this is my understanding: If I keep the AREF connected to +5V, I will be able to burn the Arduino bootloader without a problem using the tutorial, so I don't need to disconnect the AREF from +5V.

I can't really read schematics yet since I'm only a beginner.

The reason I have the reference voltage set up that way is because I followed this tutorial for a DIY Arduino: http://www.theparsley.com/arduino/diy/

I just put a jumper wire so I can easily remove this AREF. I wonder if the DIY Aruino will be able to be operated without that AREF connected to +5V, or is it necessary as in that tutorial?

geratheg

Thanks for the suggestion. I figured out the capacitor goes on the Arduino UNO R3 used as the programmer, not the device being programmed.

Another question:

To upload sketches to the new chip, I see in this tutorial http://www.arduino.cc/en/Tutorial/ArduinoToBreadboard
it shows Rx and Tx from the Arduino UNO connecting to the Rx and Tx on the Atmega328 chip respectively.

However, in Nick's tutorial where he used a programmer he wired Rx from the programmer to Tx on the  Atmega328 and Tx from the programmer to Rx on the Atmega328.

Why are these setups different? Are they both correct and do they both work?

Edit:
Looks like I found another tutorial to upload using Arduino with the same wiring used to burn onto the chip:
http://blog.biophysengr.net/2012/06/writing-sketches-to-atmega386p-pre.html

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