Runout filament detection

Hi guys. I just bought an optical sensor to enable the marlin filament runout sensor function . I use ramps 1.4. From what I know, i need to connect all three pins as following. V to V , gnd to gnd and D4 pin to signal. I have posted a picture with the Ramps 1.4 pins. But what is weird, where the circe is red, actually I get +5V instead of nothing (I have measured with a multimeter). But Red circle should be the D4, the signal pin. And the green circle I get nothing. It's like D4 signal pin and +5V pin are switched. I also switched the connections on sensor, i inserted the filament into it but the optical sensor LED is still off. I disable #define FILAMENT_RUNOUT_SENSOR // this line in marlin. What could be the problem? Because when it's working I think that LED from the optical sensor should be on.

The D4 pin is in input mode and probably with a pull up resistor. So... If you have a high impedance volt meter... You should measure 5 volts there.

You need to connect the servo power jumper to a voltage source. Probably the RAMPS board can power your optical sensor so jumping the +5 to VCC will probably give you power on the D4 connector.

I don t understand.......... why do I get in the red circle 5V when I measure with the voltmeter? it should be D4 there that means no voltage. The 5V should be in the blue circle. I followed this tutorial but my LED from the optical sensor board is not on when I plug it into the ramps.

[www.youtube.com]

The order of the pins in this videos is the same. D4 and GND on the edges and the middle pin 5V.

Quote
DOYT
I don t understand.......... why do I get in the red circle 5V when I measure with the voltmeter? it should be D4 there that means no voltage.

Look at section 13.1 and 13.2 of [www.atmel.com]

If the Rpu (Pull Up Resistor) is activated on the input pin... That pin is going to have 5 volts on it if nothing 'low impedance' is connected to the pin.

Quote
DOYT
The 5V should be in the blue circle. I followed this tutorial but my LED from the optical sensor board is not on when I plug it into the ramps.

[www.youtube.com]

The order of the pins in this videos is the same. D4 and GND on the edges and the middle pin 5V.

The Server connector pins have +, -, and signal. But what the + is connected to is optional. It isn't connected to anything until you make a decision and connect it to something.
That is what 'servo power connector' controls. The servo connectors are on one side of the reset switch. The servo power is controlled by the 3 pins on the opposite side of the reset switch.

So what you are telling me to do is this? (picture) Does the optical sensor run on 5V? It does not need 12V? When it's powered I know it has a red LED that is on. In my case now it's off but I'll try to connect the jumper and see if the LED gets red.