Capsense design hangs I2C | Cypress Semiconductor
Capsense design hangs I2C
I have a system level capsense design with 10 buttons using CY8C20434. I2C hangs when inputs are configured as capsense. Using USBtoIIC windows utility it will sometimes list the device other times it will not. If it does it can take a minute or so to get picked up. Attempting to read button status the utility indicates that the I2C protocol is working but I may or may not read status change from a button. Sometimes the status will stick for a while before returning to zero.
I created an alternative sys level project with digital inputs on the same port pins. This works fine. It is only a problem when I am configured as capsense (CSA).
Have a previous design using CY8C20234 and 10 inputs, no problems.
The same product that has the 202434 and I2C problem has 6 other identical devices configured for two 10-segment sliders. These all work correctly.
What issue with button layout, shape, trace length, etc. might contribute to these symptoms. Seems to be only difference between my slider devices and this 10-button device.
Haven't received any response from my case for this, hope I may get something thru the forum.