I set out to connect a water flow sensor to my bbb. The water/gas sensor is " G3/4 Water Flow Sensor Switch Hall Effect Flow Meter Counter 1-60L/min" When water flow in the given direction you will get a pulse. 5.5 pulses , mean 1L passed the sensor.
You connect one pin to +5V one to GND and the middle to a GPIO. This GPIO pin should be pulled up to the "high" voltage , the GPIO is set to. in our case its 3.3V So I wanted to use the on-board GPIO pull-up feature. RobertCNelson maintains a kernel for the BBB and he released the 3.19-rc3-bone2. This kernel has a new way to define the device tree. You need to define the GPIO to use a pull-up using the device tree. I first got the debian image and flashed the BBB. Here is how https://blog.fite.cat/2014/03/upgrade-beaglebone-black-to-debian-7-4-and-kernel-3-14/ I then installed the new kernel from here: https://rcn-ee.net/deb/jessie-armhf/v3.19.0-rc3-bone2/ I then got dtb-rebuilder from https://github.com/RobertCNelson/dtb-rebuilder/tree/3.19.x: git clone https://github.com/RobertCNelson/dtb-rebuilder.git I then used the example by Derek Molloy to define the GPIO pullup : https://github.com/derekmolloy/boneDeviceTree/blob/master/overlay/DM-GPIO-Test.dts I got this file and saved it under the directory of dtb-rebuilder under the sub-dir src/arm as DM-GPIO-Test.dtsi I then edit the file am335x-boneblack.dts and add this line at the end of the file: #include "DM-GPIO-Test.dtsi" Then from the dtb-rebuilder directory I ran, make , then sudo make install. I reboot the BBB, and the GPIO is now pulled up. Thanks Robert Nelson, Niv -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
