hey sorry for the delayed reply. Not sure why there is no notification for your comment. I have not encountered this issue in using this library. Maybe this was handled by the library itself.
hi, i already see the code, and i think that was active low for the relay. but in my case, I want use active high relay, did u know something to use active high with pcf8575 ?
Hii can you please upload a video . How to connect ( 2 - I/O port expander ) directly to arduino uno board I want to connect 25 relay chanel that's why . I don't know how to connect 😕 2 expander to arduino uno and write programming of 2 different expander address on it please help
Hey, that sounds like a cool idea. I will have it listed in my future videos. In the meantime, please subscribe to my channel if you have not done so. This would get you notified of any new content.
is it safe for esp32 to send 5v to vcc? I'm worried that digitalRead could damage microcontroler by sending 5v data to 3.3v pin. In other case can i send 5v and only use digitalWrite to pcf, so that no data is recieved to microcontroler, protecting it?
![Building a custom I2C chip for Wokwi simulation - PCF8575 [full walkthrough]](/img/n.gif)
good video. I have a doubt, how you avoided the floating GPIO pins of PCF8575? pullup/down resistors of which value?
hey sorry for the delayed reply. Not sure why there is no notification for your comment. I have not encountered this issue in using this library. Maybe this was handled by the library itself.
hi, i already see the code, and i think that was active low for the relay. but in my case, I want use active high relay, did u know something to use active high with pcf8575 ?
Hey maybe you can reverse the logic in your program. I have not checked the datasheet of the pcf8575 and if this can be done in hardware.
very helpfull video, thank you
Can the PCF8575 do PWM?
I'm pretty sure it's just on/off
Hii can you please upload a video . How to connect ( 2 - I/O port expander ) directly to arduino uno board I want to connect 25 relay chanel that's why . I don't know how to connect 😕 2 expander to arduino uno and write programming of 2 different expander address on it please help
Hey, that sounds like a cool idea. I will have it listed in my future videos. In the meantime, please subscribe to my channel if you have not done so. This would get you notified of any new content.
Hi, can I power the relay board with 12v?
I don't know. Can you? Lol.
If it's a 12v relay board then yeah.
is it safe for esp32 to send 5v to vcc? I'm worried that digitalRead could damage microcontroler by sending 5v data to 3.3v pin. In other case can i send 5v and only use digitalWrite to pcf, so that no data is recieved to microcontroler, protecting it?
It is not safe. You can find in the datasheet the Max voltage of a GPIO based on the Vcc voltage. You need an extra chip to do voltage shifting
Hello, very informative, i have same 5v 16 relays board and trying to work with blynk and gpio s not enough :) found your video, thank you
Hey, glad I could help. Happy exploring!