Cycle Analyst -- Throttle Causing Reboot Loop

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Sep 8, 2019
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USA, CA, Bay Area
I picked up this really novel thumb wheel which resets to center -- the idea being I can use its 2.5v center value as my "mid point, no power" and 2.5+ as throttle forward with 2.5- as proportional regen. (It's got a slightly weird range of low-mid-high as 1.785-2.5-3.23, but I figure with the CA I can scale that as needed.)

(Thumbwheel throttle salvaged from a Boosted Rev scooter)

Pretty straight forward throttle hall configuration, as far as I can tell, however, when I connect it the CA (CA3-WP) goes into what looks like a reboot loop (the screen flashes briefly, no text appears, then it shuts off and loops over again).

The "color change" on the adapter is because this plug was sourced from my LED kit (same connectors, different color +/-/sig standard). I've checked and doublechecked the pinouts, and I believe I've gotten it correct. My connector on the CA matches the docs. The CA follow pin1 as +pos, so do the LED connectors. They, however, flip -neg and signal. Hence the flipflop connection in the picture above.

To run some validations, I pulled out my power supply, set it to 5v.

For the thumbwheel, I connected +pos to red, -neg to black, and then took a multimeter and read voltage from -neg to blue. (colors from the throttle side). With the power on, the multimeter reads 2.5 and follows up and down as I move the thumbwheel.

For the wiring I plugged in a female LED kit plug into my current throttle's connector. Hooked up +pos to red, -neg to green, and bridged -neg to black for voltage read. Got back exactly what I expected, .8v -> 4.5v with twisting action.

While I was testing, there was heatshrink tube (under the thumbwheel in picture) covering each wire, so it wasn't shorting directly.

I can still plug the original throttle in (a half twist from grin) and it works fine.

Not really sure what I've mucked up here. What else could I be checking?
 

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chuyskywalker said:
I picked up this really novel thumb wheel which resets to center -- the idea being I can use its 2.5v center value as my "mid point, no power" and 2.5+ as throttle forward with 2.5- as proportional regen. (It's got a slightly weird range of low-mid-high as 1.785-2.5-3.23, but I figure with the CA I can scale that as needed.)


This sounds like they are using the same basic construction, magnets, and sensor as a throttle, but put the springloaded return point in the center of the rotation instead. The sensor itself appears to be providing the same basic output range as a hall used in a throttle.

So there's no reason I can imagine that it wouldn't work for your application.

An aside: Controllers may be made (some are, some aren't) to remain disabled if the throttle is above a certan value at power up. Won't matter for applications like yours using the CA to interpret the throttle input to a different output range, but for direct usage to a controller it might be a problem. :)



Pretty straight forward throttle hall configuration, as far as I can tell, however, when I connect it the CA (CA3-WP) goes into what looks like a reboot loop (the screen flashes briefly, no text appears, then it shuts off and loops over again).
Based on your other information, I can't see any reason this should happen, unless the current draw for this device exceeds what the CA's voltage converter can handle at the voltage your system runs at. (the higher the system voltage, the less current it can supply).

You can test for this by powering the boosted control device from your controller's 5v, instead of the CA's 5v.

If the CA doesn't reboot, then that's the problem, and has at least two easy fixes.

One is just run it like that, and the other is to use a separate 5v DC-DC from your traction battery.

A third is to eliminate other things powered from the CA 5v, or from it's 10v (like on the PAS / torque sensor connector), to leave more current available for this device instead.

A fourth is if the boosted device has any lights on it (they seem to like blue LEDs) try disconnecting those inside it. They can draw a lot of current (relative to waht the CA has available) and could cause the problem you see.

If the CA still reboots, there must be some other thing happening that is not visible with a plain voltmeter (voltage noise spikes on the throttle signal, or ground?).
 
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