Hi,
On one hand, the US5881 Hall Effect sensor (sold on AdaFruit WebShop) does not appears to work with 3.3 volts as power supply (cfr tech sheet).
On the other hand, Raspeberry GPIO are not 5v Friendly.
The US5881 usually use a pull-up resistor of 10K to +5v, the US5881 will pull-down the voltage to GND when activated.
See http://mchobby.be/wiki/images/thumb/a/a ... ontage.jpg for schematic.
For Raspberry PI, I would propose to build a resistor bridge with an additional 20K resistor between the Output Pin of US5881 and GND.
By acting like that, Output voltage should be 3.3v (when sensor not activated) or 0v (when the activated sensor pulls down the voltage to GND).
Am I right?
Regards,
Dominique
Hall effet sensor on PI
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Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/
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Re: Hall effet sensor on PI
connect the pullup to 3.3V
- jawright
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- Joined: Thu Sep 15, 2016 3:10 pm
Re: Hall effet sensor on PI
I know this is an old thread, but I'm working on a similar project and just want to make sure I am clear on the details.
Should I use a 20K resistor between the US5881 and 3.3V, or 10K resistor (as usual) and an additonal 20K resistor between the sensor and GND?
Should I use a 20K resistor between the US5881 and 3.3V, or 10K resistor (as usual) and an additonal 20K resistor between the sensor and GND?
- adafruit_support_mike
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- Joined: Thu Feb 11, 2010 2:51 pm
Re: Hall effet sensor on PI
Just connect a 10k resistor between the sensor's output and 3.3v. A 20k resistor to GND won't do anything useful.
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Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/
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