I'm new to the raspberry pi and after getting a simple temperature sensor to work bought a YL-69 (comes with YL-38 too) but can't get any analogue data from it.

http://www.tiagoespinha.net/wp-content/uploads/2014/05/2014-05-09-12.51.20.jpg are the two sensors I have currently.

My current setup is:

YL-69 and YL-38 connected via the 2 pin side.

YL-69:VCC goes to the Rasp 3.3v power pin 1.

YL-69:GND goes to the ground pin on Rasp.

YL-69:AO goes to one of my GPIO pins(3).

I'm using the pigpio python library but pi.read(gpio) just gives me a reading of 1.

What do I need to do to get this to work, any ideas?

1 Answer 1


The Pi does not have any analog inputs, you will neeed to add an ADC and connect your sensors to the ADC. Adafruit has a nice tutorial using the MCP3008. Tutsplus has a tutorial using the MCP3008 with a moisture sensor.

  • Can any ADC be used? I've just noticed I have a ADC0832 in a kit I bought. I'm happy to dig a little deeper on how to get it to work, but you might be able to save me a bit of time if it's not compatible. Thanks!
    – john
    Sep 13, 2015 at 11:16
  • I have not tried so can't say unequivocally it but a quick google search appears to indicate that it will work. google.com/… Sep 13, 2015 at 11:20
  • 1
    The first link heinrichhartmann.com/2014/12/14/… looks promising.
    – joan
    Sep 13, 2015 at 11:34
  • That tutorial seems to use up 4 GPIO pins, is that normal just to get an Analog output?!
    – john
    Sep 13, 2015 at 22:37
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    @john If I remember correctly the ADC0832 is a spi chip so it is going to require a clock, mosi, miso and a slave select so this is normal. For reference you may want to read this article en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus Sep 13, 2015 at 23:11

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