Hi.

Another question for the assembled wisdom. My telephone/internet/cable provider does a deal where I pay a fixed amount (around £5) per month, and get free* landline calls. This used to save me a lot of money, since I'm on the phone much of the day.

However, their definition of free has changed over the years. It used to be unlimited time per call, then it was reduced to 2 hours per call, now it's 1 hour per call. After the time elapses, I start getting charged at about 4p per minute, which can add up pretty quickly to amounts I resent paying

I'm looking for a widget that can be connected to the phone socket, set for a specific time period, and alert me if the on-hook time exceeds this. I can then hang up and redial if necessary, avoiding further call charges. I can't seem to find such a device, although I would have thought the utility of it would make it something someone would manufacture.

Has anyone come across something that would perform this function? If not, I may have to design one.

Pca

*For a given definition of 'free', which changes regularly and unilaterally

I know it's not up to your usual standards of elegant cleverness... but wouldn't a relay on the phone hook, connected to a simple bedroom alarm clock do what you need?

Yeah, I know... "Where's the fun..."

tanstaafl.

I'm sure you could whip something up in no time.

Two ways you could go about it, I think:

1. Software only. Packet sniff your network for the phone-call packets to determine when calls start and stop, or perhaps even just query your internet router for that information (there's gotta be a way to do it). Leave it running as a daemon on one of your computers.

2. Programmable hardware. A doohickey plugged into the telephone's end of the system. When an ordinary POTS telephone goes off-hook, there's a change in the voltage on the line (I forget whether it goes high or low). A simple timer circuit hooked up to a buzzer that resets on thosse voltage changes.

Can't do it directly with a computer, as it's an analogue phone line.

Having thought about is some more, it occurs to me I can probably use a modem to do pretty much all of it. Check the on/off hook status once a minute, start the timer, and make irritating beeping noises when it runs out. Either plug it into my mailserver in the cupboard just behind me and do it under linux, or make it standalone with a PIC.

And a friend of mine has a metric crapload (SI unit, of course. One crapload is equal to 2.43 buttloads, a common american measurement. This makes a buttload approximately 411.5 millicraploads, for further reference ) of brand-new 56k modems he can't even give away...

pca

I have one...

It's called Asterisk...

I also get to do VOIP calls and a metric crapload of other things too

Didn't you have these kind of things in pubs and student dorms around the uk too?

http://link.marktplaats.nl/233423620

Not sure if those pulses needed for that to work are still sent out though.

Right but it's an analogue phone line that plugs into your internet router, and therefore becomes VOIP data out the back end, right? (The kind of restrictions you were talking about made it sound like the kind of thing a company would do on a VOIP system.)

We're rather sheltered here in USA/Canada, with "flat rate" local calling on residential lines. Our buddies around the world generally have metered billing for everything, including local calls.

-ml

Nope. It's an analogue line that comes out of a socket on the wall. It's provided by the cable company, but it's not cable-based, it just runs in the same wiring trough. Other than that it's functionally the same as any other analogue PSTN phone line provided by BT for the last 50 years. There's no interlink with any IP based system accessible to me, although I have no doubt that once it gets back to the exchange it turns into a VOIP system of some sort.

pca