Previous versions of the RDDRONE-FMUK66 included a separate arming switch connector. The HoverGames drone kit would also include a separate arming switch. However, since the release of RDDRONE-FMUK66 Rev. C a 10 pin connector is available for the Pixhawk 4 GPS. This GPS module has an arming switch as well.
SWITCH LED OUTPUT
The HoverGames drone kit will include an pre-built arming switch with the right connector. It should not be necessary to build your own switch. This information is purely for reference purposes.
E-Switch LP1 series switch with integrated LED.
There are 3 wires on the connector and 4 pins on the switch.
Pin 3 and pin 4 on the switch have to be soldered together with a small wire.
NOTE: Pin 1 of the connector does not go to pin 1 of the switch.
Polarity of the LED is important!
JST-GH 3 pin
Switch with LED
Pin 1 - 3V3
Pin 3 - LED (+) (Join pin 3 and pin 4)
Pin 4 - Switch (Join pin 3 and pin 4)
Pin 2 - NSAFETY_SWITCH_LED_OUT
Pin 1 - LED (-)
Pin 3 - SAFETY_SWITCH_IN
Pin 2 - Switch
JST sells pre-terminated wires for the JST-GH series of connectors. This is handy, since they are difficult to crimp by hand and need a special tool. The pre-terminated wires are easy to work with and just poke into the holes of the housing and click into place.
The JST-GH "stock" wires fit in the holes nicely. You just strip a little off the end, and bend it up to catch in the hole before soldering.
Pin 1 of the JST-GH has a tiny triangle on the connector. It is normally just in white, but has been highlighted here in black.
When building this cable, pin 3 and pin 4 of the switch need to be connected. Short pin 3 and pin 4 by soldering a piece of wire in between.
You need to apply heatshrink over all three wire connections. Remember that pin 3 and pin 4 are connected and will need a larger diameter piece. Here, a small piece was applied first and pushed up against the pin, then a second (larger) piece was applied over both pin 3 and pin 4.
A double heatshrink, with a second, larger diameter piece over the inner piece makes a nice looking end result.
When completed the arming switch will look something like this: