Hi, I am Lily. I would like to know is there any capacitive touch sensor works for my project?
For my project, the touch sensor need to be able to detect the user’s palm from a distance around 20-30mm through the 2-4mm plastic housing. In this case, the touch sensor should be sensitive enough rather than only work when touching it. Does anyone have any recommendations? Thanks in advance.
I have a number of capacitive sensors and they all seem to do as you want, that is they get some signal prior to being touched.
I think that you will want to get one that just spits out a capacitance value, then you can fine tune for your application.
I dont have any recommendations on a product, I’m sure Liam or others will offer examples, I just wanted to say that you should be able to achieve what you want.
I built a capacitance based light switch mechanism where, in the dark, if you brought your hand close-ish to the switch it would illuminate the touch sensor so that you could see it to touch the right spot as I had multiple sensors for multiple lights.
The capacitance Cs can be used to adjust the sensitivity. The value of Cs use smaller, then
the sensitivity will be better. The sensitivity adjustment must according to the practical
application on PCB. The range of Cs value is 0~50pF.
But without knowing the board it’s on it’d be hard to tell.
No very helpful, I know, but I decommissioned that project years ago, and I have a number of capacitive sensors in my workshop, so cant say for sure what one I used.
Do you have a way that output a capacitance value from your sensor?
That is what I did, I had a raw capacitance reading and I hard coded the capacitance values to perform the actions based on those values.
ie 10,000 to 100,000 was a proximity and <100 was a touch.
I had a quick look at the TTP223 and couldnt find anywhere to change the sensitivity in software, Doug found the part Re: changing around the hardware side of things
I’ve used the PiicoDev Capacitive touch sensor (With an RPi Pico, not an Uno) on a couple of projects - it features software-controlled sensitivity, though I’m not certain if it’s able to detect a hand from around 30mm through the plastic.
Do you have a link to the sensor you currently are using? Note - you can also solder a wire to the touch pad to navigate it through your project, this can affect the sensitivity though!