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[DJW]

Morning All


I'm wanting to build in various containers / boxes to house various electronic components around a hull, up to 12 channels involved.  And then rather than a rats nest of conventional 3 pin connectors and wires, I was thinking of using 6 pin multiplex connectors to act as the standard connector through the boxes.  But then the gain is minimal as each multiplex connector could only carry 2 channels.  My question is can I just use 2 of the multiplex pins to take power and ground from the Rx to though the connector, then use 4 pins to carry signals from (up to 4) channels. Then split the power and ground back to the devices inside the boxes along with their signal wires.


This approach would only be used on low power aux switches, so assume no large power drain from the Rx.


(In this case Rx is a FrSky R8 Pro and the aux switches are Pololu 2803 https://www.pololu.com/product/2803 )


And if this approach is technically OK to use, any downsides..?


Thanks in advance.
David.

[C-3PO]

Hi David,
The only concern maybe some "cross channel" interference (inductance) bewteen the "pwm" signal lines if they are running side by side acting like an antenna - think you will have to try it and see what happens - not sure if ferrite rings would help with this. That said they (PWM) originate from the RX side by side 

Re the power distribution - it makes sense to me and you have already identified low current requirements so so long as adequate cable size (current flow) is used you should have no problems - as an extension to that you could even connect your power "ring main" directly to the battery supplying the RX rather than pull from one set of RX pins.

The only downside to networked power distribution is that if you have a loose connection everthing connected after it will lose power which might under certain circumstances make your hair go grey...

I know you are into Arduino - not much gain here & additional cost - but you could locate Arduino's strategically around the boat to act as local decoders connected to a 3 wire network (+ | - | DATA)  to drive all servos/switches etc

Regards
C-3PO _._

[DJW]

Hi 3PO


Thanks for the comments and confirmation that the approach is valid, and I do like the 'direct to battery' insight, makes sense.  I'm using a FrSky 8A SBEC from a 4S LiPo to power the Rx, switches and the Arduinos.


Three Arduinos in this build (1/5 Aquarama) so far, two for independent twin engine sound and one for a 'cranking' vibration motor / bilge water detector. Still using your Aquarama sound files..!  Will be posting a video when I have it hooked up.  Its all going to be modular so may try the ESP32 Sound route when I have the timings and effects figured out and the rest of the boat ready.


And my hair is already grey, so nothing to lose..!
Hope you're well.
David.

[C-3PO]

Hi David,

Following your build with interest - Your boat is certainly going to be a bit of a beast!!!

It might well be worth installing the power supply as a ring rather than a long line, might mitigate against voltage drop and also reduces impact of a "loose" connection.

I am making very slow progress* with my interpretation of an esp32 sound system - but boy does it sound good... I will be interested to compare notes with your esp32 sound when you get to that part of your project.

* slow progress due to messing around with a pond side WiFi configured Submarine Leveller with whistles and bells and bells on the whistles 

Regards
C-3PO _._

[DJW]

Haha...  like the ring approach. I'm already getting frustrated with the current approach. Wires everywhere.


Just uploaded a video to illustrate where I'm at with current sound system. Since recording I've added the vibration motor to sync with the startup sounds.


https://youtu.be/sct1FfVY3TU


Your Sub leveller sounds interesting. Is there a thread running..?


Best regards
David.

[Akira]

I like he powe ring idea as preented. It was commented that possibly connecting the ring directly to the battery a=ather than going thru the receiver. I would extend a word of caution here. First, if the receeiver is operating on 5V, then you would neeed to connect to the receiver power supply, be it a BEVR or 5 volt battery. If the receeiver, as some now are capable of, is able to operate off 12v, then great, but you should make sure thta whatever is drawing power from the ring is capable of thata voltage as well. Most electronic switches , for instance, opertae off reveiver voltage, ie 5v.I ddo like the approach though and I may use it on my upcoming project, now that I have bought 40 meters of servo wire, LOL.

[JimG]

Replying to the original post, I have used this to allow for the connection of 4 servos in one plug. The two outer connectors are used for power and the inners for servo signals. This has been used for the connections to the wings on aircraft and has worked well, normally with mini or micro servos. I have used this with one large model using high power servos without any problems although I did double up on the power leads to the connector. I generally use the thicker servo wires to allow for higher currents.
Jim