The recent arrival of both Dorji 433 GFSK (Gaussian Freq. Shift Keying) data modules & 08M2 PICAXEs has set me pondering a decent matched application. Perhaps a 433.92 MHz ("434") data repeater may suit their joint horsepower ? The idea of course is that ground level gathered data, perhaps normally obstructed by buildings & terrain, could be received by an elevated repeater & then rebroadcast for the distant receiver. Radio hams & TV stations have been doing this for decades with voice & video, employing a split (typically 600 kHz for VHF hams) between the received & outgoing frequency so retransmission is instantaneous. In data terms however a store & forward approach on the same freq. would do fine, with short delays tolerable.
Years back I rustled up a simple DS18B20 temperature repeater, & this gave excellent results. However no serious attempt was made to ease the 10s of mA level current drain. If battery drain was to be minimised (especially if solar power was used) then some way of sensing incoming signals & awakening the snoozing setup would be essential. In spite of probing around the DRF7020D13 modules RF section, neither an RSSI or WOS (wake on signal) feature was found. Dorji make a simpler FM module which has these, although it may not be compatible. However their more powerful (& hence not legal) DRF7020D20 apparently does at least offer an RSSI tap. Note -the ease of use & GFSK (Gaussian Freq. Shift Keying) features of the Dorji are really appealing,so I'm tempted to continue with these.
Any thoughts or experiences welcomed. AFAIK such 434 MHz data repeaters are legal providing power levels are respected- quite a number of $$$($) commercial ones are available. Stan.
Years back I rustled up a simple DS18B20 temperature repeater, & this gave excellent results. However no serious attempt was made to ease the 10s of mA level current drain. If battery drain was to be minimised (especially if solar power was used) then some way of sensing incoming signals & awakening the snoozing setup would be essential. In spite of probing around the DRF7020D13 modules RF section, neither an RSSI or WOS (wake on signal) feature was found. Dorji make a simpler FM module which has these, although it may not be compatible. However their more powerful (& hence not legal) DRF7020D20 apparently does at least offer an RSSI tap. Note -the ease of use & GFSK (Gaussian Freq. Shift Keying) features of the Dorji are really appealing,so I'm tempted to continue with these.
Any thoughts or experiences welcomed. AFAIK such 434 MHz data repeaters are legal providing power levels are respected- quite a number of $$$($) commercial ones are available. Stan.
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