Completly new with a few questions

Projects General Guidance
1

Hi, i am completly new here and with this dev board aswell and have a few questions for a project im thinkg about.

I think what i want is a basic A to D but i want to store them in memory and then pluck them out of a registry addr via RS485/485 modbus?

So i may have 20 sources all range from 0 - 5v and i want to store them in locations where they can be looked at via rs485?

Is this possible witht his board and how many channels does or can arduino support?

Thanks
Andy

2

Boards have six, eight or sixteen analogue inputs (expandable with external multiplexers, costing digital pins), but all have only one A/D converter, so spreading the inputs over more inputs means lower per-channel sampling rates.

RS485 will require external hardware too.

3

Ok, what about RS232? does arduino support RS232 without any external harware? and is there a RS485 shield for Arduino?

Thanks
Andy

4

does arduino support RS232 without any external harware?

No.
(you could, but I don't recommend, probably use one of the software serial libraries to directly drive a roughly RS232-compatible interface straight in and out of the pins, but this relies on protection diodes, and could easily damage your controller. I've done it with PICs, but it is very, very dirty)

5

Ok, thanks again for the answer, although i still a little confused to weather this is viable or not?

Is there a 485 module for Arduino, ive googled and it appears as though there is?

And would this let me just look at registry address, i assume i would program locations them in the software?

Andy

6

gibbon:
Is there a 485 module for Arduino, ive googled and it appears as though there is?

You want someone to confirm the results of your web search? There are lots of threads and articles on it already. Try going to the Arduino Wiki and use the search there for starters. 'Module' could be taken to mean 'shield' or 'library'. You probably want both, and in the case of a library, I assume something like modbus or DMX. (I know nothing about these, they could even be the same thing, I just found them in a search.)

And would this let me just look at registry address, i assume i would program locations them in the software?

If, by 'registry address', you mean that you would write a sketch where you store your measurements in an array, and also retrieve them in response to query on the comm interface, then this sounds absolutely fine to me.