Hello, i have a project that need a TFT display with touch shield and arduino nano and i2c sensor for humidity and finally an analog sensor for temperature.
the display need pins A0-A3 to function correctly and I'm using A4-A5 for i2c communication, but still need an analog pin to read temperature.
my question is can A4 act like SDA and analog pin, so that with some code can communicate via i2c than read analog valley in analog pin A4?
i don't want to use an arduino mega, it will be an overkill.
if it's possible, than how to make a connection and what code i should write to make both functions working?
Nano has pins A6 & A7, analog in only.
Hi.
Which Nano do you have ?
Nano != Nano Every, but with that one i don't expect your sketch to work.
The (much smaller) chip used on a Nano, unlike its brother on the Uno, has additional A6 and A7 pins.
These pins are supposed to be lead out to the Arduino pins, and can only be used as an analogue input.
See this pinout diagram, posted in another post here in this very forum:
So why not connect your temperature sensor to A6 ?
You'll even be able to connect another sensor (perhaps to see how bright it is outside ?) to A7.
can A4 act like SDA and analog pin, so that with some code can communicate via i2c than read analog valley in analog pin A4?
No because it would corrupt the I2C signal bus when it was reading analog voltage.
You can't have an I2C bus just 'sitting on the bench' while you're reading an analog voltage.
As Ken Kesey used to say:
""You're either on the bus or off the bus." | by Vincent Carriuolo | The Observer Is The Observed | Medium"
Ok, thanks for all replies, so my thought was to add pnp transistor on A4 so that with digital pin can turn pnp and read Analog value, than turn pnp off and continue I2C.
anyway, it's easier to use A6.
As stated, I2C is not something you switch on and
off like that. If it were you could probably use analog switches like the ADG511/512.
"https://www.analog.com/media/en/technical-documentation/data-sheets/ADG511_512_513.pdf"
Please answer the questions.
Which Nano (there seem to be seven different ones).
A 'classic' Nano has A6 and A7 broken out, which can be used for your (unspecified) temp sensor.
Or maybe the (unspecified) humidity sensor has a built-in temp sensor.
Or maybe use a digital temp sensor. One-wire, or I2C.
Leo..
I have a classic arduino nano and I'll use A6 as an analog pin.
Thanks for all replies, and sorry for delay to answer.