Ultra flat signal and power cables to go through window frames

I need to get 9V 2A power and seven signal cables through a window frame.

I found this for power, and it works well, but nothing for lower current 5V signal carrying cables (sensor to microcontroller); traditional ribbon cable is too thick.

Any ideas?

Thanks!

perhaps flat cable(s)

Thanks for your suggestion!

I tried one from an old scanner, but that could not withstand being sharply bent 90° multiple times like that power cable I already found.

In some way, this ultra-flat stuff, very similar, one finds in consumer electronics like cameras, etc. would be a solution, as that goes around sharp angles a few times, saw it also in my old laptop, but that stuff is custom-made and I don't know who sells this stuf in "boring" straight strips.

You could try sticky backed copper tape. It's used for lead lighting (stained glass) artwork. It is bare unprotected copper so would need some coating to keep it from corroding. Perhaps cut it into thin strips and cover it with kapton tape.

When you say multiple bends, do you mean 2 or 3 90° to get installed, or they get bent periodically?

I agree with the copper tape suggestion. If you don't have Kapton tape, heavy clear packing tape works well too.

Or you could use the power cable for signals too? Only the short distance to cross the window.

That link gave you the keywords - FFC Flat Flexible Cable - to search for, they are widely available.

On the window and frame you could remove the sharp corners with a file (or other suitable tool) in the area where the cable passes though. so that the cable can have smooth bends rather than abrupt 90 degree creases.

JohnRob: When you say multiple bends, do you mean 2 or 3 90° to get installed, or they get bent periodically?

Permanently, with most window frames here, there will be six bends, like with the flat power cord linked to above. I can't botch it with self-made stuff as it's for a citizen science project. I thought about simply using four flat power cords, but they are fairly wide, but in the worst case that might be the option. I found this and many similar ones, but they want you to buy huge quantities, not selling to individuals. Maybe I just have to look around longer to find a low quantity vendor (I'm in Europe) here. Thanks all for your suggestions!

Lagom: Thanks for your suggestion!

I tried one from an old scanner, but that could not withstand being sharply bent 90° multiple times like that power cable I already found.

In some way, this ultra-flat stuff, very similar, one finds in consumer electronics like cameras, etc. would be a solution, as that goes around sharp angles a few times, saw it also in my old laptop, but that stuff is custom-made and I don't know who sells this stuf in "boring" straight strips.

If you search for "flat flex cable" you should be able to find straight runs in various lengths.

What about using RF link instead?

Thanks, good idea... I used packet radio before (TX and RX both inside or both outside), not through triple glazed windows though, but it may work? You have some experience with that? WLAN does not penetrate strongly enough, when the router is somewhere inside people's appartments.

With packet radio, I would need some kind of "bridge" solution inside, receiving packet radio and transmitting WLAN. In the past, not being a professional coder, I never succeeded resolving library conflicts if the microcontroller had to make use of RadioHead and WLAN functionality at the same time successfully : (

litz wire ?

Possibly... don't have any. This set-up has to go outside the window of several high-rise appartments and must be safe-ish for the people who live there.

Packet radio, if it goes through the window would be great, if only I knew how to make a reliable bridge inside to WLAN. Have to search for tutorials about that.

instead of litz you can use small diameter enameled wire ( 0.3mm ) and scotch tape, just to pass the window frame after that use regular cable. or arduino wifi, i2c ?

The obvious way to extend the WiFi range is to use a repeater. :roll_eyes:

Trouble is the glass. Modern triple pane windows are UV coated with some metallic stuff and gas filled, and that blocks WLAN very well, hence the idea to find ultra flat cables for the stuff outside and have the WLAN ESP32 module inside. Seems like appartments in various high-rises today are like Faraday cages. Cellular not too good either, not that that matters.

Glass doesn’t block wifi, the walls around them do. As long as you’ve got your transmit and receive antennas in line of sight, there should be no problem.

Lagom: Possibly... don't have any. This set-up has to go outside the window of several high-rise appartments and must be safe-ish for the people who live there.

Packet radio, if it goes through the window would be great, if only I knew how to make a reliable bridge inside to WLAN. Have to search for tutorials about that.

In that case, the window frames are likely steel or aluminum. Why not tell us what material you are dealing with? Paul

They're from 2002, modern wood plus aluminium construction, double and triple pane.

I'll pester some flat flexible cable vendors first, if they can be persuaded selling to an individual who doesn't need 100 metres per day, lol.

In any case, making a packet radio to WLAN bridge is interesting, too, if one can overcome the library conflict problems.

Thanks again for the many good suggestions.

79galinakorczak: instead of litz you can use small diameter enameled wire ( 0.3mm ) and scotch tape, just to pass the window frame after that use regular cable. or arduino wifi, i2c ?

I forgot to add - DIY rainbow cable using scotch tape and 0.3 mm wire, 0.1 is also ok , I just made it for curiosity.