Jasper on POTS (telephone)

[Ned McNeil]

I just finished getting a Jasper implementation running on a rPi b3+ over the land-line phone system still wired into my house, that has long since been disconnected from the telephone company.

I hacked a telephone apart to connect my Raspberry Pi's headphones out to where the sacrificial telephone's microphone was, and tapped off the phone line to input into a USB sound card functioning as Jasper's "USB microphone". Now, Jasper's sacrificial phone is always off-hook, and i can pickup any other phone in the house to connect to the line, and interact with Jasper "over-the-phone": when I query into the telephone handset, Jasper responds into my earpiece.

If there is community interest, I will finish drafting up the electrical schematics for the circuit I ended up using for this implementation. (I used an LM386 to amplify jasper's output into the phone "mic")

I hope to further implement some sort of signaling from the phone hook to the GPIO on the Pi so that, I do not need to query in spoken: "Jasper", but instead take an edge-detection of "phone-becoming-off-hook" as the query, then I can pick up the phone and go right into speaking my command.

[Adam Peacock]

I'm in the process of converting Jasper to Python3 so, pls share if you feel your work could help someone else! ;)

//adam

[Ned McNeil]

glad to see the forums aren't completely dead in these corona times.

i just drew up this electrical schematic of my current setup, it's attached.

i'm happy to field questions/provide updates as they arrive.

[Peter Peterson]

Hi, new to the forum, and That is a genius way of reusing an existing closed system. I'll admit I'm a little rusty on reading diagrams but if I was looking at that right it looks like the system is not entirely dependent on corded phones correct? 

I mean you would have to change the edge detection but in theory you could use anything that connects to a land line as an input. Such as an intercom with a push button or use an intercom that is always listening as a mic and have one in every room that you have a land line in.

I am currently going back to college for programming and electrical engineering and this sounds like a very fun project to implement as part of my studies. when I get to go back in the fall (cross fingers and knock on wood) lol

[Ned McNeil]

yeah -- that it correct: with my current setup, any device that can interface with POTS level audio can be connected to the line where the phones go (though, if you were building your own system that utilizes your house's old phone lines and planned to not use any phones at all, a differently engineered supporting circuitry might be more elegant for your application, you might not, for example, have to power the devices from the same line as the audio is transmitted, which would omit the need for the DC biasing and filter)