karbiuch
Junior Member level 1
Hi
I wrote simply program to send data from uC to PC. I use PIC UART and ft232. It works.
Now, I would like to transfer my weather measuring system from my room to the garden. USB does not work at such distances (20m). That's why I decided to use RS485. I think, the easiest solution is to use RS485 in full duplex configuration. Unfortunately, the microprocessor does not send or receive messages from PC. My connection cables are very short, 0.2m. In my opinion, this is a hardware problem. I cant find solution to fix it. Could you check if I have a mistake in the electrical schematic?
I tried to add a 120ohm resistor and a 3.3V to 5V converter. It doesn't help.
https://datasheets.maximintegrated.com/en/ds/MAX1487-MAX491.pdf
I wrote simply program to send data from uC to PC. I use PIC UART and ft232. It works.
Now, I would like to transfer my weather measuring system from my room to the garden. USB does not work at such distances (20m). That's why I decided to use RS485. I think, the easiest solution is to use RS485 in full duplex configuration. Unfortunately, the microprocessor does not send or receive messages from PC. My connection cables are very short, 0.2m. In my opinion, this is a hardware problem. I cant find solution to fix it. Could you check if I have a mistake in the electrical schematic?
I tried to add a 120ohm resistor and a 3.3V to 5V converter. It doesn't help.
https://datasheets.maximintegrated.com/en/ds/MAX1487-MAX491.pdf