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Topic: Arduino Uno Rev3 pinouts photo (Read 105282 times) previous topic - next topic

SarahC

Just a heads up peeps!

Some of the AVRISP ribbon cables - to 6 pin plugs have the little triangle denoting pin 1, pointing to pin 5 instead!

I noticed the colors of the wires were accurate, so I made sure the black cable was in the opposite corner to the white dot. =)

Nick Gammon

Yes, my USBtinyISP cable is crimped the opposite way around to the AVRISP one. But I just put the red wire on pin 1. Can be a trap if you are used to the cable snaking a certain way across the board. :)
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

Docedison

#2 screws (2/56) screws will work on that hole... (all holes)
But just barely.
My question is... Why are the pins on the digital side of the board
Not on a common (0.1"/2.54 mm) grid?. The spacing on the Digital
side of the board between connectors is 'off' grid by .05"

Fine Job, Nick. Saves a lot of difficulty for those of us who are
hard of 'seeing'.

Doc.
--> WA7EMS <--
"The solution of every problem is another problem." -Johann Wolfgang von Goethe
I do answer technical questions PM'd to me with whatever is in my clipboard

That is the great un-answered question.  My guess is, it was a mistake on the first board that just kept rolling forward.  The only other alternative is that they wanted you to buy accessories from them, but given the origins of this error and the mind-set of the Arduino team initially, I tend to discount this explanation.
Facts just don't care if you ignore them.

Nick Gammon

It does have the advantage, intentionally or not, that  you can't (easily) rotate a shield around 180 degrees and insert it the wrong way around.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

Claghorn

I just got an AVRISP mkII and looking at the description of it's cable, I get the impression that the nearly invisible arrow head mark on the end of the cable (same side of the connector as the red wire) should be plugged into the ICSP header on the R3 to match the nearly invisible white dot on the silkscreen. (Correct me if I'm wrong before I blow something up :-).
http://home.comcast.net/~tomhorsley/hardware/arduino/arduino.html

Marius

Rather people think you to be a fool than you open your mouth and confirm it.

Nick Gammon

There's an arrow? (looks carefully).

I just make sure the red wire lines up with the dot on the silkscreen.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

Claghorn


There's an arrow? (looks carefully).


Only in the right light: It is a small triangle that isn't as glossy as the rest of the connector :-).
http://home.comcast.net/~tomhorsley/hardware/arduino/arduino.html

poriet

Hello Nick,
Only just today come across your website which looks pretty good.

BTW, I'm a newbie and many of the replies are heavily jargon-laden and thus tricky to follow. This may have been covered already, but.......
The SCK and SCL have 2 lots of connectors. I got a copy of an Arduino Uno from 'Sainsmart' in an offer I couldnt refuse.
On this board the SCL and SCK outputs on the digital side of the board have been omitted.

Perhaps you can sort out a confusing issue for me. A new ATMEGA328 needs to have the bootloader loaded before it will accept sketches. I dont understand why. A blank PIC chip can be programmed with a Hex file. Is this because the sketch is being loaded into the chip via the TX and RX pins and not through the ISCP header  ( MOSI/MISO)?

Bruce

CrossRoads

"On this board the SCL and SCK outputs on the digital side of the board have been omitted."
Sounds like an older Rev board.
SCL/SDA are accessed thru th A4/A5 pins.

Question 2 -Yes.  Blank chip gets bootloader installed via SPI pins SCK, MOSI, MISO; bootloader then runs and accepts data via serial port and loads it into memory.
HEX file can also be downloaded via SPI pins; sketch then runs immediately without bootloader checking to see if a sketch download attempt was started.
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.

Nick Gammon


A new ATMEGA328 needs to have the bootloader loaded before it will accept sketches. I dont understand why. A blank PIC chip can be programmed with a Hex file.


It's the same as PIC really. See this page:

http://www.picaxe.com/What-Is-PICAXE

From that:

Quote
If you purchase 'blank' PIC chips they will not work in the PICAXE system, as they do not contain the PICAXE firmware. Therefore always buy pre-programmed 'PICAXE chips'.


So the PICAXE also needs a bootloader before it accepts sketches, via the serial port. In both cases you can use the ICSP to upload things (including the bootloader). In both cases, once you have the bootloader you can upload further sketches via the serial port.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

poriet

OK Thanks guys: the fog is starting to clear a little. Onwards and upwards!
Bruce

bperrybap


From that:

Quote
If you purchase 'blank' PIC chips they will not work in the PICAXE system, as they do not contain the PICAXE firmware. Therefore always buy pre-programmed 'PICAXE chips'.


So the PICAXE also needs a bootloader before it accepts sketches, via the serial port. In both cases you can use the ICSP to upload things (including the bootloader). In both cases, once you have the bootloader you can upload further sketches via the serial port.


PICAXE is quite a bit different from Arduino.
PICAXE really provides a language and uses an interpreter for tokenized code. You cannot extend the language.
You can only do the commands provided in the language.

Arduino is not really a language but a framework. Since it uses C/C++ it is infinitely extensible.

Where you can run into issues on PICAXE is that it you cannot extend the language so if you want
to support some new device that is not supported by the language, you have implement it by using
the interpreted language constructs which will not be nearly as fast as the machine code you can get
when using C/C++

On the positive side, PICAXE includes some excellent debugging tools - which is something that the Arduino does not have.


-- bill

mixania

Hey guys, I'm just curious and I want to answer some questions:

1.What is SCL and SDA pins for? Are these some how helpful when integrating into a project?

2.What is Interrupt pins 1 and 0 for?

3.And how to use the TX and RX pins?
Arduino Uno R3
Mac OSX Lion

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