I am developing a project that may use 4 touch inputs on a 14M2. Reading about touch, it seems that people have trouble with drift due to changing environmental conditions.
I found a couple of descriptions of auto calibration but they use the same inputs that may or may not be touched. I'm wondering about using a spare input as a touch reference level. Has any work been done already comparing different touch inputs and how their levels change? On the 14M2, I can use 4 port B pins as touch inputs and there's a 5th touch input to use as the reference.
Should the reference changes be applied as differences or proportions to the in-use input levels?
The application is for a Dawn Simulator alarm clock using an MSF clock input, OLED display and PWM output for dawn simulation.. There's also an ambient light detector to adjust display brightness to suit the light level.
Are any of these, in particular the PWM, likely to upset the touch inputs?
I realise there's lots of scope for my own experiments here but the project is intended as a present due in 2 weeks so there's not much time for in-depth background work!
Does this approach have a reasonable prospect of success or should I stick with push buttons as before?
Derek
I found a couple of descriptions of auto calibration but they use the same inputs that may or may not be touched. I'm wondering about using a spare input as a touch reference level. Has any work been done already comparing different touch inputs and how their levels change? On the 14M2, I can use 4 port B pins as touch inputs and there's a 5th touch input to use as the reference.
Should the reference changes be applied as differences or proportions to the in-use input levels?
The application is for a Dawn Simulator alarm clock using an MSF clock input, OLED display and PWM output for dawn simulation.. There's also an ambient light detector to adjust display brightness to suit the light level.
Are any of these, in particular the PWM, likely to upset the touch inputs?
I realise there's lots of scope for my own experiments here but the project is intended as a present due in 2 weeks so there's not much time for in-depth background work!
Does this approach have a reasonable prospect of success or should I stick with push buttons as before?
Derek