Error in number of pins in Technical specs on Arduino Nano description

[hujth330]

The page: https://store.arduino.cc/arduino-nano
The problem is In the Technical specs table, row 11:
"Digital I/O Pins: 22"
that's an error, the number of digital pins in arduino Nano is 12.
My guess- it's a typing error.
Please fix as soon as possible.
thank you.
hujth330

[matthijskooijman]

I suspect the digital pin count includes the TX and RX and analog pins, which are also usable as digital pins (except for A6 and A7 which are analog only, so the correct number of pins would be 20, not 22).

However, for example the Arduino Uno does not count like this and says "14 digital pins" (including RX and TX, but not the analog pins). It might be better to stay consistent with that and change the Nano specs to say 14 digital pins too.

It might also be good to add something like " (Also usable as digital pins)" with the Arduino Uno's analog pins, and something like " (of which 6 are also usable as digital pins)" to the Nano. Other boards should be updated likewise.

[oqibidipo]

This was brought up in the forum:

SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication, which, although provided by the underlying hardware, is not currently included in the Arduino language.

[matthijskooijman]

Ah, thanks for adding that. For clarity, this text:

SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication, which, although provided by the underlying hardware, is not currently included in the Arduino language.

is on the Nano reference page, but it seems it is no longer current, since the Nano supports SPI just fine.

[kengdahl]

So is this solved?

[per1234]

@kengdahl no, it's not solved.

There are two problems:

1. How should digital I/O pins be counted on the product page "Tech Specs" tab?

Some product pages only count the number of pins which do not also have ADC functionality, others add the ADC pins that can also be used for digital I/O. Some say one thing on their "Tech Specs" tab and another on their "Documentation" tab. On the Leonardo and Micro boards the SPI pins broken out to the ICSP header can also be used for digital I/O but those pins are not currently part of the count.

Board Name	Digital I/O pins broken out	Digital pins on product page	Includes ADC pins in count
Uno	20	14	No
Mini	20	14	No
Nano	20	22	Yes
Ethernet	20	14	No
Lilypad	20	14	No
Lilypad Simple	9	9	Yes
Lilypad SimpleSnap	9	9	Yes
Mega 2560	70	54	No
Mega ADK	70	54	No
Leonardo	23	20	Yes
Leonardo ETH	23	20	Yes
Micro	23	20	Yes
Lilypad USB	9	9	Yes
Yun	23	20	Yes
Yun Mini	23	20	Yes
Industrial 101	?	20	Yes
101	20	14	No
Due	66	54	No
Gemma	3	3	Yes
Tian	?	Undocumented	NA
Zero	20	20	Yes
M0	20?	20	Yes
M0 Pro	20?	20	Yes
MKR1000	?	8	?
MKRZERO	?	22	Yes
MKR FOX 1200	?	8	?
MKR WAN 1300	?	8	?
MKR GSM 1400	?	8	?
MKR NB 1500	?	22	?
MKR WiFi 1010	?	8	?
Arduino Vidor 4000	?	8	?
ARDUINO UNO WiFi REV2	?	14	?

So you can see it's really a mess. Decide on how they should be counted and use that method consistently across all product pages. My preference is for the Digital I/O Pins count to be the full count of how many pins can be used for Digital I/O, regardless of what other properties those pins might have. A frequent misconception we see on the forum is people not realizing they can use digitalRead() and digitalWrite() on the An pins.

2. Incorrect digital pin count for Nano.

No matter how you decide to count them, 22 is wrong.

https://store.arduino.cc/usa/arduino-nano

Change:

Digital I/O Pins 22 (6 of which are PWM)

to:

Digital I/O Pins 20 (6 of which are PWM)

OR

Digital I/O Pins 14 (6 of which are PWM)

[per1234]

Make that three problems, the incorrect documentation regarding the Nano's SPI pins also remains:
https://store.arduino.cc/usa/arduino-nano (Documentation tab)
Change:

SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication, which, although provided by the underlying hardware, is not currently included in the Arduino language.

To:

SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication using the SPI library.

@per1234 No change after more than a month.

[per1234]

We now have a dedicated issue for the incorrect documentation of the Nano's SPI pins: #8467

We can restrict this issue to dealing with items (1) and (2) above.