I'm using a 3.3 MCU and a 5v logic RS-485 IC. I'm trying to send out some data to another controller. I don't have a logic level shifter as of now. So I decided to use resistor divider, to get it to a safe limit of 3V.
simulate this circuit – Schematic created using CircuitLab
The output I'm getting is confusing. When I don't connect the 3V RX data out to the MCU RX Pin, the logic levels are working fine.
But when I connect this RX out pin to the RX pin of the MCU then the voltage level seems to float.
I checked the ground levels and it was just the same. Then I thought it could be some impedance issue, but nowhere it explicitly states the impedance of the UART input pin.
What's wrong here? If it helps, I'm using TI's C2000 series controller.