iTead iBoard not able to access A6 and A7

Development Other Hardware Development
#1

I bought this remarkable board and we all know that Arduino IDE supports analog pins till A5 when it comes to Duemilanove or UNO but how to access these pins then there the link to this board >> http://iteadstudio.com/store/index.php?main_page=product_info&products_id=511

and here is the schematic >> http://iteadstudio.com/store/images/produce/Platform/ArduinoCom/IBoard/sch-iboard.pdf

The thing is that iForum is down there is a loop back problem in there websites Forum Link

#2

To use A6 and A7 you need an entry in boards.txt that says:

typename.build.variant=eightanaloginputs

What "board" do you select when uploading to this board?

#3

Hi john I select deumilanove with 328p in the boards.

#4

NI$HANT: Hi john I select deumilanove with 328p in the boards.

Try selecting "Arduino Nano w/ ATmega328" instead. That should give you access to A6 and A7.

#5

Try selecting "Arduino Nano w/ ATmega328" instead. That should give you access to A6 and A7.

This is not working, I think i need to make the boards.txt entry.

#6

NI$HANT: This is not working, I think i need to make the boards.txt entry.

"Not working" in what way?

#7

"Not working" in what way?

Hi John,

I mean i tried using the simple Blink sketch on Pin 21 (A7) while selecting the Nano w/328p in boards but things didnt work

Regards, Nishant

#8

NI$HANT:

"Not working" in what way?

I mean i tried using the simple Blink sketch on Pin 21 (A7) while selecting the Nano w/328p in boards but things didnt work

"Things didn't work" in what way?

#9

I mean it should have blinked(the LED) as im just using it as the output digital pin.

#10

You can’t use those two analog input pins as digital pins, at least not with digitalWrite().

To use them for digital I/O you’ll have to use direct port access:

portMode(A6, INPUT) -> DDRC &= ~(1<<6);
portMode(A6, OUTPUT) -> DDRC |= 1<<6;
digitalWrite(A6, HIGH)  -> PORTC |= 1<<6;
digitalWrite(A6, LOW)   -> PORTC &= ~(1<<6);

portMode(A7, INPUT) -> DDRC &= ~(1<<7);
portMode(A7, OUTPUT) -> DDRC |= 1<<7;
digitalWrite(A7, HIGH)  -> PORTC |= 1<<7;
digitalWrite(A7, HIGH)  -> PORTC &= `(1<<7);
#11

I don't think you can use A6/A7 as digital pins AT ALL. They are only connected to the analog mux.

#12

westfw: I don't think you can use A6/A7 as digital pins AT ALL. They are only connected to the analog mux.

Oops! You're right. The ADC6 and ADC7 pins have no other purpose. They are not part of any I/O register. PORTC doesn't have a BIT 7 and BIT 6 is connected to the Reset pin if the RSTDISBL fuse is set (Reset is disabled). If the Reset pin is not disabled, writing to that bit will do nothing and reading it will always return 0.

#13

A6 & A7 is pure analog input pins.

#14