> Possibly the most requested feature, automatically setting the timezone based on the GPS coordinates was essential. However, most people don't realise how complex this process is, at least within the restrictions I'd given myself: no internet or cellular modem, nothing beyond the GPS data, and a USB port for occasional updates.
> If we had an internet connection, sure, we could just query an online service. But I don't want my clock to require wifi.
> If we had a cellular modem, we could get the time from the cell towers, which is broadcast through a protocol called NITZ. This is how phones auto-update when you enter a different timezone, but it's somewhat unreliable depending on the carrier, and overall worse than using GPS. And I really don't want my clock to have a sim card.
> I'd also like, just for the sake of it, for the clock to work anywhere in the world, even at sea.
> This means we need to keep a copy of the map data for the country outlines for the whole world. It also means we need a full copy of the timezone database, and have the processing power onboard to make use of all this.
> Auto timezone
> Possibly the most requested feature, automatically setting the timezone based on the GPS coordinates was essential. However, most people don't realise how complex this process is, at least within the restrictions I'd given myself: no internet or cellular modem, nothing beyond the GPS data, and a USB port for occasional updates.
> If we had an internet connection, sure, we could just query an online service. But I don't want my clock to require wifi.
> If we had a cellular modem, we could get the time from the cell towers, which is broadcast through a protocol called NITZ. This is how phones auto-update when you enter a different timezone, but it's somewhat unreliable depending on the carrier, and overall worse than using GPS. And I really don't want my clock to have a sim card.
> I'd also like, just for the sake of it, for the clock to work anywhere in the world, even at sea.
> This means we need to keep a copy of the map data for the country outlines for the whole world. It also means we need a full copy of the timezone database, and have the processing power onboard to make use of all this.