A way to add analog pins to arduino ?

Other Hardware General Electronics
1

hello guys,
i would like please to know if there is anyway to add more analog pins to an arduino uno ?

thanks in advance :slight_smile:

2
3

florinc:
MCP3008 - 8-Channel 10-Bit ADC With SPI Interface : ID 856 : Adafruit Industries, Unique & fun DIY electronics and kits

and can i work with all the pins together ? i mean if i changed for 2 or 3 pots in the same time will that work fine ?

4

8 channels. This means 8 pots in the same time.

5

i asked because i was searching and i read on some forum that it can't take signals at the same time but u can fast forward the time and it looks like in the same time

i can't find tutorials for this with arduino :frowning: anything here on the website ?

thanks :slight_smile:

6

You can't take a reading from all 8 channels simultaneously, you have to read one channel, then the next, and then the next etc, until you have read them all.

You can do this rapidly, so that the readings appear to be simultaneous.

This is no different from using an Arduino's own analogue pins.

7

On Arduino you have A0 to A5 just define each pin separately in sketch. You can use up to 6 analogues input.

8

yea that's right, but i need please another chip then the one suggested by florinc, because i couldn't find it

9

firashelou:
yea that's right, but i need please another chip then the one suggested by florinc, because i couldn't find it

Locally?
Well, there are the "old" CD4000-series multiplexers. The CD4051 is 1 to 8 (or 8 to 1, either way.)
http://www.jameco.com/Jameco/Products/ProdDS/13098.pdf
More info with your websearch - "Arduino 4051"
More info available in your websearch: "Arduino 4051"

Adding a link
Arduino Playground - HomePage
More info with your websearch -- "Arduino 4051"

10

The CD74HC4067 chip is another option.

11

thank you guys for the help :slight_smile:

12

zoomkat:
The CD74HC4067 chip is another option.

SparkFun Analog/Digital MUX Breakout - CD74HC4067 - BOB-09056 - SparkFun Electronics

i couldn't find this chip alone without the PCB, it's a PCB by sparkfun, the chip alone is SMD which won't work with me :frowning:

13

The 4051 chips are easy to get in a DIP form. You could wire them like in the attached pix.

4051 larger.jpg
4051 larger.jpg712×800 30.9 KB

14

A Leonardo has 12 analog pins and a Pro Micro has 9 analog pins, would just switching boards from Uno meet your needs?

15

Megas are getting inexpensive.

16

zoomkat:
The 4051 chips are easy to get in a DIP form. You could wire them like in the attached pix.

thank you i managed to find this one and now i am learning to work with it :smiley:

17

dmjlambert:
A Leonardo has 12 analog pins and a Pro Micro has 9 analog pins, would just switching boards from Uno meet your needs?

nice idea but unfortunately i can't do it :frowning: because i am making standalone circuits and working with leo or pro micro won't do the job because of the space available

but my question is : Is there anyway to make a standalone leonardo :smiley: ?

18

Well, the Pro Micro is an extremely small Leonardo. There is not much to it, just the main processor, a regulator which you may or may not need in a standalone situation, a couple of resistors and capacitors and crystal. I recommend checking out the schematic. The SparkFun schematic they have on the web site has some errors around SS and MISO pins, and I tried to get SparkFun to make corrections but they only made it worse. A github issue I raised was fixed, but only for the v13.1_3.3V branch. The master and all other branches are messed up. To view the accurate schematic use Eagle and open the .sch file. Or just be aware of the problems on the .pdf schematics you see online around the SS and MISO pins.

https://raw.githubusercontent.com/sparkfun/Pro_Micro/v13.1_3.3V/Hardware/Pro_Micro.sch

19

ok thank you,
well i have tried the Pro Micro before and because i come from Uno background i found it not confortable to work with the Pro Micro and it has many problems

So far the 74HC4051 is working but it has a problem i don't know if it is the Software or a Hardware problem but so far i can make a conclusion that it is a Hardware problem with the name of the ports I/O

20

So far the 74HC4051 is working but it has a problem i don't know if it is the Software or a Hardware problem but so far i can make a conclusion that it is a Hardware problem with the name of the ports I/O

On the 4051 chips make sure the three control pins do not float. I've used high value resistors to ground on them to make sure they don't float when not high, otherwise you might get erratic operation.