Making serial cables
The purpose of this tutorial is to clarify the assembly of the DB9 serial to "5 Pin MTA connector" cable used in FabLab. I hope it is clarifying.
First thing is to know what connect to!
Thanks to Jan we have these beautiful drawings of the connectors and the connection.
- One female DB9 serial connector
- One 5 Pin MTA connector
- Flat cable with 5 wires
- Wire Cutter
5 Pin MTA Connector
Note: Start by the 5 pin MTA connector because it is easier to do this with the wire order of the flat cable.
Important: Check if the wire exits the connector in the same direction that it exits the board. Important: Leave a 3 cm tip on the other end of the connector. It could be useful to troubleshooting.
The cable is done!
Know one must check if it is well connected.
Place a male connector to the female db9 to access easily to the pins. Also place a male connector in the MT5 connector for the same reason. Then with a multimeter as an Ohmmeter, check for continuity in the corresponding pins.
If you don't have continuity it can be one of two things.
- Misplacement of the wires in the pins. Check the other pins were you were not supposed to have any continuity.
- Not enough pressure in the back shell of the connector and therefor no contact. To check that remove a little bit of isolation of the excess cable that was left before, and measure continuity between this tip and the pin in the back of the auxiliary male connector. If you don't have continuity press a little harder and check again.