I’m trying to improve my understanding of how these things work so would appreciate it if anyone can help me.
I have managed to get communication going back and forth using XBees and 232 Explorer shields and am now looking at 485.
I went with a 232 shield for the XBee as it obviously does more than just connect the right pins to the D-Sub (I did try that first) but I don’t really know what.
Now I’m looking at 485 comms I’m having trouble finding a current 485 shield, especially one that isn’t very expensive.
Then I found this thread
Few years old but the last comment discusses a way that you can do 485 comms without a 485 chip which, I guess is what I’m also using on the Explorer board (but a 232 one obviously).
Does this mean there is a way for me to send and receive 232 from an XBee without a conversion chip / board? And the same for 485?
Has anyone on here done these things?
The XBee products are 3V CMOS level devices. If your Processor or device is also a 3V CMOS level device, then you can connect the XBee directly to it without the use of a level shiftier.
RS485 does require a chip as you are using one of the radios line as a TX Enable. Also the radio does not offer true RS485 as that is either 4 wires (two for Tx and two for Rx) or 2 wire (Differential Tx Rx lines).
Thanks mvut again for your help
I see, so I suspect I the reason my 232 comms didn’t work is that the device I’m connecting to is 5V (I think), does that sound right?
And using a 485 chip would allow me to use the 2 available pins on the XBee and the chip would do the necessary conversions?
So is what the person said on that thread not possible then?
Yes that does. You must use a level shifter between the two devices for it to work.
No, using an RS485 chip will not give you more lines. You have the same Tx Rx lines for RS232. You actually reduce it by 1 line as you need to use a TX Enable pin where by on RS232 you do not.