arc19
Posts: 18
Joined: Mon Jul 08, 2019 1:59 pm

Add Analog Pins to Raspberry Pi Model 3 B+

Wed Jul 10, 2019 2:28 pm

Is there some kind of alternate hardware I can use to add Analog Input Pins to my Raspberry Pi Model 3 B+?

pcmanbob
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Re: Add Analog Pins to Raspberry Pi Model 3 B+

Wed Jul 10, 2019 2:34 pm

You need to add an analogue to digital converter the MCP3008 is one commonly use on the pi , it will provide 8 analogue inputs,

but as the pi only has a 3.3v gpio you can only measure voltages up to 3.3v , for high voltages you need to use a potential divider circuit on each input to reduce the voltage to 3.3v maximum.
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arc19
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Joined: Mon Jul 08, 2019 1:59 pm

Re: Add Analog Pins to Raspberry Pi Model 3 B+

Wed Jul 10, 2019 5:18 pm

Oh ok thank you!

Andyroo

Re: Add Analog Pins to Raspberry Pi Model 3 B+

Wed Jul 10, 2019 5:37 pm

If you do not fancy building a board, you could use this https://thepihut.com/products/raspio-analog-zero as it is small and has space for a little bit of circuitry for the incoming signals...

arc19
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Re: Add Analog Pins to Raspberry Pi Model 3 B+

Thu Jul 11, 2019 2:56 pm

Interesting okay thank you. You mean if I used this board, I wouldn't have to make an external potential divide circuit?

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B.Goode
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Re: Add Analog Pins to Raspberry Pi Model 3 B+

Thu Jul 11, 2019 3:33 pm

arc19 wrote:
Thu Jul 11, 2019 2:56 pm
Interesting okay thank you. You mean if I used this board, I wouldn't have to make an external potential divide circuit?
You still have to be prepared to scale your input voltage to match the range acceptable to the mcp3008 ADC chip.

This board usefully simplifies the connection of the external ADC chip to your RPi. That's all. No magic...

pcmanbob
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Location: Mansfield UK

Re: Add Analog Pins to Raspberry Pi Model 3 B+

Thu Jul 11, 2019 3:35 pm

arc19 wrote:
Thu Jul 11, 2019 2:56 pm
Interesting okay thank you. You mean if I used this board, I wouldn't have to make an external potential divide circuit?
NO its still using the MCP3008 and if you read the user guide for the hat it states
The MCP3008 is powered by the Pi's 3.3V (3V3) rail. This means that the highest voltage the chip can measure directly is 3.3V.
Edit...
out typed by B.Goode again :lol:
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gordon77
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Re: Add Analog Pins to Raspberry Pi Model 3 B+

Thu Jul 11, 2019 3:53 pm

arc19 wrote:
Wed Jul 10, 2019 2:28 pm
Is there some kind of alternate hardware I can use to add Analog Input Pins to my Raspberry Pi Model 3 B+?
You could add an Arduino, connected by usb or i2c etc, it will provide 5 analog inputs, multiple digital in/out....

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