Hi,
I want to connect the Rx pin from one arduino to the Tx pin on another and talk at a baud rate of 115200 (or maybe slower if I have to).
Any idea what the maximum distance I might be able to achieve is? I'm hoping for at least 10 meters.
The cable will be 6-core flat phone-type cable (unshielded) that will also be supplying the power to one of the units.
Ok, I know i could do some experiments to find out, it just thought it would be easier to ask first!
thanks
High baudrate, no line drivers, bad cable, and 10 meters. That seems to me like you are at (or over) the limit.
With RS-485 line drivers and twisted pair wires, 100 meters is no problem.
It also depends on the cable, although they all look the same, there is a difference in quality.
How reliable do you want it to be ? Do you have a protocol to repeat messages ?
How reliable do you want it to be ? Do you have a protocol to repeat messages ?
Doesn't need to be very reliable, the data flow will be one-way only, will be a number between +-90 degrees, and will probably not actually vary that much.
I can probably just slow the baud rate and do some error correction or averaging.
Cheers
Yes, that would be the best option.
Between 1200 and 9600 baud, and a checksum byte.
How do you use the 6 wires ? I assume it is a flat cable ?
A ribbon cable has specific electrial characteristics.
You should decouple the power wires at the start and at the end of the cable. Or else a power peak might interfere with the data lines.
Perhaps like this:
1 = GND, on outside to avoid electric noise from outside.
2 = 5V, next to ground, because the current is 'paired' with GND.
3 = spare, perhaps for interrupt or data in other direction.
4 = spare, perhaps connect to ground at the transmitter size and open at receiver side
5 = DATA
6 = GND, on outside to avoid electric noise from outside.