Futaba GV-1 RPM Sensor

ArduCopter Traditional Helicopter
1

(Note: I did see this post but I figured it’s a few years out of date so I thought better to start a new one)

I’ve got a GV-1 sensor hooked up to cube orange on the work bench. I’m using a cordless drill with the magnets on it as my test setup. It seems to be working, and reading acceptably. But when I happen stop and the sensor lines up with one of the magnets I get the ISR Flood issue. I’ve tried various combinations of pull up and pull down resistors and nothing seems to change the issue.

Hooked up to an oscilloscope I can see the sensor is working, but after the ISR flood error the cube will not report any RPM. Cube Orange on AC 4.4.1 (heli)

Any suggestions on how to alleviate the ISR Flood error before I start drilling holes and gluing in magnets?

2

ISR flood means that the input signal is oscillating. FC disables the interrupt to avoid saturating the CPU with handling of the sensor.

The issue lies within the sensor, it appears to “bounce” under some specific magnetic field strength.

3

This suggests that my test rig (aka: Cordless drill and hand held sensor) may be part of the problem. I’ll come up with something a little less sketchy and see if the problem goes away.

Thanks!

4

I would try simply swinging the magnet across the sensor with your hand. You should be able to reach maybe 200RPM :slight_smile:

5

I was using the drill because it’s close enough to the main rotor speed that it would tell me if things were at least reasonably accurate. Roughly 1200-1300 rpm. I noticed much below 600 -700 rpm the sensor would report on the cube, even though I could still see a reading on the oscilloscope. Again, this could be related to the cordless drill so I’m not going to panic yet.

6

IIRC there is lower boundary setting so low RPM is reported as 0.

1 Like
7

Hi @Allister , it’s not a Cube or sw related problem. Use this sensor instead.

1 Like
8

Just an update if anyone is searching this in the future:

Don’t bother with the GV-1 sensor. I could not get it to work consistently or without the ISR Flood issue. I tried numerous combinations of pull up and pull down resistors. I improved my test setup, and nothing worked. So I gave up on it.

I ended up with the Align Beast RPM sensor, and it works fine. The only issue is the wiring is non-standard. I found this link and it got me through: MICROBEAST PLUS Governor - How to modify ALIGN rpm sensor (HE50H22) - BEASTX Wiki

From the link (if it goes away in the future)

First of all please note that the wiring colors of the sensor do not apply to any standard!
The red wire is the ground wire and the black wire is the wire that plugs into the positive
pole of the power supply. The white wire transfers the rpm signal.

I have Graupner sensor that @Ferrosan suggested on order, but I seem to be having trouble finding them in my country right now so the Align will do the trick.

1 Like