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Help with a simple (I thought) circuit

gambcl 4 years, 10 months ago

Hi folks, I am trying out Fritzing to diagram a circuit for a hardware programming cable that I would like to make. I have a circuit diagram from someone who has made this cable and used it, so I know the circuit works. I am trying to recreate it in Fritzing and then after trying it out on a breadboard I might order a PCB to build it into a project box.


Basically the cable input comes from a USB FTDI RS232 cable which terminates in 6 wires, so I have a 6-pin header on the left side of the diagram, the cable output is another 6-pin header on the right side of the diagram.

Two of the input wires just go to output pins via resistors.

One each of the input and output pins are connected to Ground.

One input pin is 5v, which is fed into a voltage converter to output 3.3v, which is then fed to a switch, which then connects to both an output pin and an LED (with resistor) to indicate when the button is being pressed.

The other pins are not connected.


I tried drawing the schematic, which seemed to go fine. Then I tried arranging it all on a breadboard and when I had finished I had ratsnest lines appearing on my schematic, but I can't figure out why. When I try to delete the ratsnest wires on the schematic things pop out of the breadboard, and so on.

I feel like I'm missing something.

Am I doing something obviously wrong here? I am new to electronics tinkering, doing this mainly as a fun/learning exercise, so I could easily be doing something stupid.


The cable diagram can be see here:


And my attempt at Fritzing it is here:


If anyone has 5 minutes to spare to see if I am going crazy or just missing some basic knowledge I would be very grateful.


Thanks for any help,