dpdtledswitches
I am looking to push a button and one led comes on when i push the same button again the first led goes off and the second light comes on. alternating lights each time the button is pressed. one light should always be on.
I was hoping to use a microswitch as the button i want to use has a microswitch that i was going to switch. Would this be a dpdt? Does that exist in a latching pushbutton. Any other circuit ideas that would work?
I appreciate the input
You apparently were looking for a push-on, push-off switch. What you got was a momentary pushbutton switch that's normally open.
As per my comment, the "Off-(NO)" position description is a little incorrect; it should be "Off-(On)" which simply means the switch has two positions, off and on, but the on position is momentary, thus in parenthesis.
The seller also describes it as "latching" which should mean that a single push changes its position, and it stays there until the next push. Technically that would mean it's also not momentary, so the description is contradictory.
I'd ask the seller for a refund or replacement. I frequently order non-critical parts from Hong Kong or Shenzhen, China via eBay and generally have good results. Most of the sellers from those locations are very concerned about feedback and maintaining a good reputation, so you should get an amicable response.
Modify HDMI DPDT push button with an NPN to control with GPIO pin?
It will be quite easy to modify, though there are two distinct circuits you need to drive separately. You will need to remove the DPDT switch to get correct remote operation.
HDMI switches (with manual pushbutton selection) all use one of various HDMI multiplexers to change the TMDS/Clock and DDC/CEC signals from one source to the other. This multiplexer is usually controlled by a logic signal which could be directly driven by external logic.
There may be a simple SPDT switch (one half of your physical pushbutton switch) which switches over the +5V supply from one source to the other.
A typical chip used for the data switch may be like this FSHDMIO8
The most likley configuration inside you switch box would be like this:
simulate this circuit – Schematic created using CircuitLab
If you remove the DPDT switch you should be able to wire in a relay module made for Arduino use without too many problems. An example of what you could source is here and it's schematic shown below. Search for "DC 5V DPDT Relay Module Board for Arduino" and you'll find several options.
This particular module drives the relay with an NPN transistor and will work (the IN signal) for both 3.3V and 5V MCUs, however the itself relay requires 5V for operation. For example this would work if your MCU were a Raspberry Pi, where the I/O signals are 3.3V but there is 5V available to power the relay.
Best Answer
An alternating (push-on, push-off) pushbutton switch would be the easiest. It needs to be SPDT (or better). There are plenty available.
simulate this circuit – Schematic created using CircuitLab
If you want to connect it to an MCU or other logic, then R2 can be used to assure a valid '0' logic level, otherwise you don't need R2.