Hi, I am working on an IR remote using STM32L412RBT6P. I have the touch sensing system working to provide the buttons for the user. The user touches a button to send an IR (RC5) code and an LED flashes to let you know it happened.
Q1:I have one touch channel that holds the pressed condition for 2 to 3 times longer than the the others. You can clearly see this in Cube Monitor when looking at the Delta's. You can see the channel 3 (Red) is holding the touched condition longer in the attached image. All touches are as similar as I can do. All sensors and PCB tracks are very similar to each other. What effects the duration of the touched condition?
This channel is connected is TSC_G2_IO1 (PB4). After laying out the PCB I discovered UM1913. This recommends PB4 is only used for the active shield, which I have allocated to TSC_G1_IO1, Shield and IO3, Capacitor. Does this contribute to the longer touched time?
Q2: I am currently running the clock at 20MHz. If I reduce it 2MHz to get into Low Power Run Mode are there any issues with the touch system I need to be aware of?
I recall reading the clock should not be too high for the TSC, have found no recommendations about the lower frequencies.
Any advice gratefully appreciated.
Thanks in advance, Lance.
