Some quesions about 3v3 and 5v

Hi everyone,

I'm new in the forum, but I've been using Arduino for a while.

I come from an Arduino Due which doesn't work now :frowning: , and I think I damaged the chip because of some issues with 3v3 and 5v.
Now I'm about to buy a new Arduino (Genuino in my country) board, probably the 101, which works with 3v3 too and I wanted to find out some things to work more safely with the new board.

  1. I read about a '5v tolerant' "feature" about Genuino 101 pins... What does this mean? If I'm using a component (like an LCD) which works with 5v connected to Genuino 101, will pins work (it used to with the Due, even if its pins weren't '5v tolerant')? Or will it stop working to protect the chip from 5v?

  2. Coming from a Due (54 digital in/out and 12 analog in/out) I'm used to use a large number of pins (especially the digital ones)... I saw this shield. Now the question is: on the shiled I see it requiers 5v power (am I right?), so will this damage some of the pins? Will it work?

Last, but not least, do you think this Genuino 101 is worth its price? Or are there some better Arduino boards for my purposes (basically the two points explained above plus some computing power)?

Thanks everyone in advance :smiley:

Hi,
the "5V tolerant" description means that you can apply 5V to the pins and you won't damage the board, while it will continue working as expected.
Most shields contains chips that can be powered by both 5V or 3.3V, and the right design is to check IOREF pin to decide which power source to use; if it doesn't happen, the 101 design lets you use shields/components which were designed for older AVR boards (5V only).

About the second question, the 101 has the same pin count and capabilities of the UNO, plus the accelerometer and BLE. You can of course use a multiplexer shield like the one you linked but if you need 5V compatibility and a lot of pins and you are not interested in BLE the best choice is probably Mega2560 (https://store.arduino.cc/product/GBX00067)

Hi,

I was thinking about the Mega 2560 too, but I'm also interested in BLE, accelerometer and gyro...
If you tell me that the mux shiled I linked is ok for the 101 I'll buy this one :slight_smile:

Thnak you anyway

ddg_99_arduino_due:
Hi everyone,

I’m new in the forum, but I’ve been using Arduino for a while.

I come from an Arduino Due which doesn’t work now :frowning: , and I think I damaged the chip because of some issues with 3v3 and 5v.
Now I’m about to buy a new Arduino (Genuino in my country) board, probably the 101, which works with 3v3 too and I wanted to find out some things to work more safely with the new board.

  1. I read about a ‘5v tolerant’ “feature” about Genuino 101 pins… What does this mean? If I’m using a component (like an LCD) which works with 5v connected to Genuino 101, will pins work (it used to with the Due, even if its pins weren’t ‘5v tolerant’)? Or will it stop working to protect the chip from 5v?

  2. Coming from a Due (54 digital in/out and 12 analog in/out) I’m used to use a large number of pins (especially the digital ones)… I saw this shield. Now the question is: on the shiled I see it requiers 5v power (am I right?), so will this damage some of the pins? Will it work?

Last, but not least, do you think this Genuino 101 is worth its price? Or are there some better Arduino boards for my purposes (basically the two points explained above plus some computing power)?

Thanks everyone in advance :smiley:

Some other notes:

  1. Yes you can use 5V hardware. This is because a 3V3 signal is understood as a HIGH in the 5V system, and 5V won’t damage the board because it’s protected and will also be undestood as a HIGH in the 3V3 system. But I need to tell you something, you shouldn’t have connected a 5V LCD to a due, this is because due is not protected, so even though 3V3 would be understood by the shield, 5V in any of the due’s pins would damage it.

When things say they don’t work it doesn’t mean you can’t plug it, but you will significantly reduce their life time or break them, as with that due.

  1. It won’t damage the pins because they are protected.

Last: 101 is worth the price, yes; but is it useful for you? As said I would pick Mega 2560 because it seems to fit better your projects. However, buy what you think it’s the most useful for you.

edsa:
Some other notes:

  1. Yes you can use 5V hardware. This is because a 3V3 signal is understood as a HIGH in the 5V system, and 5V won't damage the board because it's protected and will also be undestood as a HIGH in the 3V3 system. But I need to tell you something, you shouldn't have connected a 5V LCD to a due, this is because due is not protected, so even though 3V3 would be understood by the shield, 5V in any of the due's pins would damage it.

When things say they don't work it doesn't mean you can't plug it, but you will significantly reduce their life time or break them, as with that due.

  1. It won't damage the pins because they are protected.

Last: 101 is worth the price, yes; but is it useful for you? As said I would pick Mega 2560 because it seems to fit better your projects. However, buy what you think it's the most useful for you.

First, thank you too :slight_smile:

Then, when I used to work with the due, I knew it worked at 3v3 but I didn't know that 5v would damage its chip: I discovered it just now that it doesn't work anymore because it was gifted to me when I was totally a newbie. I'll pay more attention on my future boards now that I know.

As said I'm interested in BLE and acceletometer, so I'm definitely for the 101 if it stands even 5v (but I'll try to be less self-confident and more caring).

Thank you all!