Arduino pro mini pin types

Hello,

I have Arduino Pro Mini, exactly this one:

http://www.dominicdube.com/blog/arduino-pro-mini-pinout/

and Arduino Nano:

I designed a driver board for CILE 2088-5RGB led matrix. Board consists of 4 daisy chained 74HC595, tree of them for cathodes rows and fourth one for driving power sourcing IC TD62783AG (since the led matrix is common anode). Driver board works fine, led matrix works fine, Arduino code works fine. However...

On NANO everything works as expected when I connect to daisy chained 74HC595s with pins:

const int dataPin = 2;
const int latchPin = 3;
const int clockPin = 4;
const int oePin = 5;

and everything magically stops working when I connect this pins:

const int dataPin = 4;
const int latchPin = 5;
const int clockPin = 6;
const int oePin = 7;

On Pro Mini both cases works fine.

Maybe this is a simple question but - what am I missing here???

I was looking like crazy at the Pro Mini and NANO pinout charts and obviously did not find an answer so I'm writing here.

Can anyone explain me what is the difference between pins D5 and D6 on Pro Mini and NANO? On above pinout charts NANO D5 and D6 are marked with asterisk * but it doesn't say what does it mean...

Snippets of code often leave out important information.

I do not know why it would work on one set of pins versus the other. It should. Did you set the pinModes right.

The asterisk means that that pin is a PWM capable pin.

I would suggest you spend a few hours with the Arduino cookbook, it will be invaluable in helping you understand what is going on with the Arduinos. It will also give you a good insight on how the code works.

"The asterisk means that that pin is a PWM capable pin."

Well, no it doesn't. This sign '~' indicates PWM. The asterix, or the 'star' character for clarification stays unexplained.

As for the code - the code is fine as it runs with no problem on Pro Mini. It is the NANO which is different in some way, so what I'm looking here is for some more detailed hardware specification. If anyone could point me out to it, I would appreciate greatly.

benderooo:
It is the NANO which is different in some way

The NANO and the Pro Mini use the same processor type, so the pin types will be the same.

If you go to the Arduino pages for the NANO and Pro Mini you will be able to download the schematics.

Possibly a hardware problem on the Nano, try connecting LEDs and running test code to make sure pins 6 and 7 actually work properly.

Could you show a schematic?

Well, no it doesn't. This sign '~' indicates PWM. The asterix, or the 'star' character for clarification stays unexplained.

If you look closely at the markings on the Nano board in the link, you will see that each PWM pin is marked with an asterisk. And only the PWM pins have the asterisk.

asterisk.jpg

asterisk.jpg

Ah, indeed. Apologies, the asterisks are there.

Well, I’ll go with suggestion of faulty hardware then. Will check it out.

Yes, the nano and pro mini should be directly interchangeable - the only difference should be that on the nano, pins 0 and 1 are connected to an on-board serial adapter, and on the pro mini, that's external. Every other pin should behave identically.

Different pin mappings? Curious that the problem is with 6 and 7 ... hopefully this maps to the appropriate MCU pin for D6 and D7 because we know A6 and A7 are analog only.

dlloyd:
Different pin mappings? Curious that the problem is with 6 and 7 ... hopefully this maps to the appropriate MCU pin for D6 and D7 because we know A6 and A7 are analog only.

The compiler should treat 6 and 7 as pins D6 and D7, unless they are used for an analogRead. Hard to imagine that the OP would be wiring this wrong, since they have it working properly on a Pro Mini, and they obviously know the difference between analog and digital pins for the other connections. There should not be any difference in compiler behavior between a Nano and Pro Mini, much more likely there is a hardware problem since the code actually works on the Nano using different pins.

david_2018:
Possibly a hardware problem on the Nano, try connecting LEDs and running test code to make sure pins 6 and 7 actually work properly.

You were SO right.
I run a simple test putting all pins HIGH/LOW every 1sec and tested the output. D6 did not get to 5V ever. So I took a look at the processor itself and viola! No solder point on where the D6 pin supposed to be connected.
I am rather seasoned software developer, started with electronics about 3 year ago. Software is easy but all this this 'electric' part keeps me on my toes :slight_smile:
I guess the lesson here is: when something doesn't work, always re-visit and check absolute basics :o

This is solved now.
Cheers to all.

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