KMtronic or SDR-05V Cable

APT supports Canon/Nikon shutter cable based on USB Relay Broads. It is very easy way to make a cable and requires no electronics skills and no soldering! Other advantage is that there is no need of Serial-to-USB adapter, the cable is connecting directly to an USB port.
There are to options for relay boards:
1. KMTronic USB Relay Board (https://www.kmtronic.com/usb-relays.html/usb-relay-controller-one-channel-pcb.html). Once the cable is ready, the option KMTronic based shutter cable in Main Settings tab has to be enabled and the COM port should be selected  in the Long Exposure Control
2. Any USB Relay Board based on SDR-05VDC-SL-C chip like this one AliExpress link Once the cable is ready, the option "USB Relay SDR-05" should be selected  in the Long Exposure Control. We have report that this board also work fine.
Flows the instructions how to make the cable.
You need three main things:
1. A USB Relay Board
2. The cheapest possible shutter control for your camera
3. USB cable
The other things you will use are: something to cut wires, isolation band and a screwdriver.
Step 1
Cut the remote controller cable near to the button in order to get longer cable attached to the connector. Remove the isolation from the there wires and connect the cable to the camera. Turn the camera on. Start connecting the wires in a pair to see which pair will shoot an image (in this case it is the Blue and the White). There is no risk to damage anything! This is the same what the remote controller does ;)
Step 2
Cut the unneeded wire and isolate it with some band. You can use the plastic bag - cut one of the ends like on the picture ( smaller cut would be better :) ). If there is need shorten a bit the not isolated parts of the wires and connect the them to connectors C and NO (leave NC free) using the screwdriver. The green LED will be turned on during exposure so you may want to be visible...
Nikon specific: The remote controller has 3 wires Yellow, White, Red (R) and two positions - half press to focus and full press to take image. It makes contact between Yellow and White to focus and all three for image. So the working configuration is to connect White+Red to C, Yellow to NO. Your remote controller could have other wire colors, but the logic should be same.
Step 3
Isolate the board somehow. On the picture is given one option. Other is to use white isolating band (white in order to see the green LED) and wrap both cables and the board in one package. If you have suitable plastic box, it can do the job...
Do no use metal box!