I am having a problem to read values from my temperature and humidity sensor(XY md02--> http://www.sah.rs/media/sah/techdocs/xy-md02-manual.pdf) whish is attached to my ravpi core. I enable the modbus master and in pictory i add modbusRTU master. Device path is /dev/ttyUSB0, baudrate is 9600, patity...

I have RevpiCore with 4GB of memory. is it possbile to upgrade this to 8GB , 16GB or 32GB of memory, replacing memory or on some other way.

Thanks,