The antenna is the number one factor in distance. A good antenna, cleared from obstacles is the easiest and most effective way to go. Next one is receiver sensitivity, but that's not so easy to improve and impossible on a low budget. What remains is power, improving that tends to be illegal. It is quite effective though: i have a digital link to a station with an indoor antenna, 15 km away. Most of the time 10 watts is enough, but sometimes interference requires up to 40 watts. But is has worked every day ;) One day (without snow) the antenna will be moved outside and then 5watts will probably be more than enough.
Last option is to reduce the (single skip) distance, by using one or more repeaters of some sort along the path. Create an automatic mesh network will add a lot to your project;) Joep Op zaterdag 16 februari 2013 schreef Sebastien Lelong ( [email protected]) het volgende: > Hi guys, > > > On 16 February 2013 08:11, Oliver Seitz > <[email protected]<javascript:_e({}, 'cvml', '[email protected]');> > > wrote: > >> >> Can't you just use a timer to program it such that the towel heater is on >> before you wake up ? >> >> You're such a spoilsport ;-) >> > > Indeed Sunish, not that fun at all :) I could even use RTC on my Bee for > this, and set an alarm, but... > > Wake up times can vary, and I "need" a way to sync my towel heater with > this. Ultimately I would write a program which scan my alarm clock on my > phone, create events on my calendar accordingly so heater is synced. And, > more, if for any reason, I don't wake up, my system would turn off heater. > I monitor light, temp, humidity, power consumption, publish them to Cosm, > all of these produce "wake up" patterns when reading graphs. If this > pattern wouldn't appear, then it would be turned off. > > >> >> RF over four stories is a long way... It's going through wall the better, >> the lower the frequency is. RC model cars and planes used to use something >> like 27MHz, maybe it's worth trying such a remote control. Or, if you dare >> to build RF by yourself, try something below 10kHz. Those frequencies are >> usually not restricted by any laws, and will easily even go through wet >> concrete. Be careful to only send a clean sine wave, for any harmonics will >> likely result in a visit by the police ;-) >> > > I was pretty sure RF 433MHz modules would do it... I need to test some > other options. As for power line carrier, there's no such power line on my > cellar. I was hoping to find a way to communicate between floors, using an > ultra low consumption setup on batteries... > > Thanks & Cheers, > Seb > > -- > Sébastien Lelong > > -- > You received this message because you are subscribed to the Google Groups > "jallib" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:_e({}, 'cvml', > 'jallib%[email protected]');>. > To post to this group, send email to > [email protected]<javascript:_e({}, 'cvml', '[email protected]');> > . > Visit this group at http://groups.google.com/group/jallib?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- You received this message because you are subscribed to the Google Groups "jallib" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/jallib?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
