Just got the RS-485 breakout board that uses the SP3485 and am having trouble identifying the pinouts I should use for the A/B signals. want to mount in on a board with a 0.1" pitch and the 0.1" holes don’t line up. Specifically, when I put the header in the set of holes marked for the Arduino side (Tx/Rx/RTS/Vcc/Gnd) the 0.1" holes on the other side don’t line up. Is there a figure that clearly identifies which holes are which (like by the J number on the schematic)? Am I using the correct holes? Do I happen to have a defective board?
Can you post a photo of your board?
don’t see how.
if I figured it out top and bottom view attached. the 5 holes on the top are the computer interface. the three on the bottom are the bus. spacing between pins is 0.1" but from top to bottom does not line up with a 0.1" space board.
You can use the header on the 5-pin side and three pieces of solid wire (like a resistor lead) on the 3-pin side. You may want to verify the spacing on the breadboard as it looks like both the spacing of the holes and pads are all over the place.
/mike
I know that is a solution. I can use pins on either the 5 pins OR the 3 pins because the spacing between the pins is correct. I was hoping that I was missing something or was trying to use the wrong pins. Would have been nice is they had put the J numbers on the board to match the numbers in the schematic.
The square pad on the RJ-45 pads is pin 1. The pad numbers go up as you zig zag your way down the connector.
If you’re just looking for the RS-485 pads, those are the pads labeled A, B, and G on the edge of the board.
tks but looking to mount it on a “mother board”