Land-Surf Platysense for VESC

The Platysense pad is really great for use with VESC due to some unique characteristics. Unlike every other sensor available, the voltage that it returns is variable based on pressure applied, instead of a binary on or off signal. As you apply progressively more weight to the center of the pad, the ADC voltage will increase from the base “unweighted” voltage up to over 3V. This allows you to fine-tune the sensitivity of the pad, and since VESC tool allows you to tune ADC 1 and 2 voltage thresholds separately, allows you to set it up as a 2-stage activation.

Important note: there is a “break in” period for a new platysense sensor, during which the unweighted voltage will be higher than after breaking it in. When setting ADC thresholds, look at what it’s showing when unweighted and add at least 0.5V for the lower value. Check it regularly until it’s fully broken in, it can fluctuate up and down and you really don’t want the lower ADC threshold set below the resting voltage. My pad initially showed 1.5V unweighted, after breaking it in it now rests at 0.01V.

The entire surface of the footpad is pressure sensitive, but the edges are less sensitive than the center. By assigning asymmetrical values to ADC 1 and 2, you can set it up so that it works like this:

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So if I am getting this right I check the values when I am standing on it normal and set that for ADC2. Then I do a heel lift and set just a bit lower than that value on ADC1. That way it should stay activated when doing sharp turns since only ADC2 gets deactivated when on the edge but if I am going slow enough it will deactivate like a heel lift. I can’t wait to test this tonight.

The edges of mine don’t seem to be any less sensitive than the middle. I tried mutiple different placements but standing normally gave me ~3.1V and on the edge I was getting ~3V. They vary a bit so I couldn’t get it to work.

Interesting, thanks for the feedback. I have another platysense that I have only used on an FM board so far, and then another one ordered but not shipped yet, so soon I’ll have 3 total… I’ll see if I can find any sort of consistency between them. On the store page it specifies that the front-side heel lift is the recommended way to disengage it, which I had no problem with on the FM board, which I assume uses 2.5V as a threshold (no proof just gut feeling based on my Platysense behavior).

My heel lifts look like this: Platysense heel lift - YouTube

How much do you weigh? It could be that even though the edges are less sensitive, you’re still pushing it up to max voltage… I’m 150 naked, maybe 180 when fully geared and loaded with cargo.

I can get it to heel lift like that but its just getting fully off the sensor. That type of heel lift works with symmetrical ADC values.

I still get a voltage reading even standing on the edge like that. It’s a low value, like 1-1.3V, which I try to keep my lower ADC under.

Just a small warning from my own experience, the platy can idle as high as 1.7 in very cold weather. Not sure where youre located but just something to keep in mind…

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Yeah, I was miraculously spared a disaster the other day… put a brand new platypus pad on a new build, idling at room temperature at 1.5V, set thresholds to 2.2V, then went for the maiden voyage in 35 degree weather. I had a really awkward dismount trying to go around a mound of dirt in the sidewalk, and the board tipped over on its side, and… wheel kept spinning. I turned it up to 90 degrees to shut it off by the angle fault and then checked the app, it was idling at 2.3V at that temperature. :open_mouth:

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Im really happy that nothing and no one was seriously hurt and u were able to engage the roll fault. Ive made quite a lot of sensor footpads and ghosting is almost traumatic for me now haha

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