Tool/software:
Hello,
We have some carbon touch detection problems on a product.
I think it's more caused by the Keyboard definition than the TCA8418.
I try to understand how TCA8418 works.
Datasheet shows that a pull-up of 105K is on each pin ROW / COL.
So i supposed that a low output level is imposed on each ROW (sequentially) in order to detect which key is activated (Through the reading of each COL pin)
Is it correct ?
Second question. I measure an impedance of 100 ohms between pin ROW and pin COL when Key is activated. Is it problematic for the TCA8418 to have such a high impedance.
Best regards