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Project:AlarmClock: Difference between revisions
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More ideas for getting time
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== Ways of determining the current time == | == Ways of determining the current time == | ||
* NPL (was MSF) radio signal. Symtrik module is the popular option, available from [[http://www.pvelectronics.co.uk/index.php?main_page=product_info&cPath=9&products_id=2 PV Electronics]]. | * NPL (was MSF) radio signal. Symtrik module is the popular option, available from [[http://www.pvelectronics.co.uk/index.php?main_page=product_info&cPath=9&products_id=2 PV Electronics]]. Simple to decode, but very difficult to get a good signal with the supplied kit. I can just barely get a signal in Cambridge and none at all in the hackspace. It is very sensitive to supply voltage smoothness. | ||
* [http://en.wikipedia.org/wiki/DCF77 DCF77] should also be receivable in the UK. | |||
* DAB. The Venice 5 module is commonly cited, but not generally available (forums recommend buying cheap complete DAB radios and breaking them apart). See Elliot's section below. If this can be made to work, it has the obvious bonus of better radio stations. | * DAB. The Venice 5 module is commonly cited, but not generally available (forums recommend buying cheap complete DAB radios and breaking them apart). See Elliot's section below. If this can be made to work, it has the obvious bonus of better radio stations. | ||
* GSM. No idea if this can be done cheaply enough. | * GSM. No idea if this can be done cheaply enough. | ||
* GPS. Receivers can be bought cheaply, but require an outdoor or close to outdoor antenna. | * GPS. Receivers can be bought cheaply, but require an outdoor or close to outdoor antenna. | ||
* Mains frequency and BBC longwave radio both offer relative time signals, but are not enough to determine the absolute time. | * Mains frequency and BBC longwave radio both offer relative time signals, but are not enough to determine the absolute time. | ||
* RTC module from [http://proto-pic.co.uk/real-time-clock-module/ Proto-Pic] - not a radio controlled time module but a tiny module which quotes a minimum life of 9 years with the built-in battery. In a production setting this could be set to the right time at the factory. | |||
== Prototypes == | == Prototypes == | ||
