As mentioned in my last blog post, I've also been looking at the panasonic DPT ("Digital Proprietary Telephone", also known as the "Digital Super Hybrid System")
This is a digital signalling format, with a lot of similarities to an ISDN BRI.
Audio is transmitted as G.711 (u-law or …
For quite some time, I've been reverse engineering the Panasonic APT ("Analog Proprietary Telephone", also known as the "Advanced Hybrid System") protocol.
This is a protocol for carrying button press information from phones, and also for carrying status information (LED controls and text to be displayed on an LCD …
To balance out the complexity of the last project, here's a very simple (but useful) project that doesn't have any active components at all.
When working with telecoms equipment, it's very common to need to connect RJ45 (8P8C) or RJ12 (6P6C) connectors.
Although it's possible to buy patch cables and …