PCA9555DB Usage issues

guibin — Fri, 22 Mar 2024 06:11:56 GMT

PCA9555 is used as input. When the remote control transmitter runs for a certain period of time (unexpectedly), the input signal suddenly locks, that is, the value read from the register no longer changes. No matter how the external switch changes, it is useless. After the power is turned off and restarted, it will Return to normal (other input signals except pca9555 are normal, only the input port related to pca9555 has a problem).We want to understand under what circumstances this phenomenon occurs, what changes we can make, and whether it can be avoided through procedures.

Re: PCA9555DB Usage issues

JozefKozon — Fri, 22 Mar 2024 08:06:10 GMT

Dear Guibin,

please share your schematic with voltage levels and part values. Please connect an oscilloscope to the input pins to which you send the signal and please share the scope. To confirm, that the signal fulfils the VIH and VIL levels requirements. Please connect an oscilloscope or a logic analyzer to the I2C lines, when you try to read the input port registers and please share the results.

With Best Regards,

Jozef

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PCA9555DB Usage issues

Re: PCA9555DB Usage issues