FPV visor discussion
Posted: Fri Oct 14, 2011 7:14 am
Hi all. I decided to go for next step in RC flying, FPV. For starter, I try to keep it low cost, but reliable. I got 5.8GHz bevrc video link, built helical & cloverleaf antennas, I have frsky telemetry system. But the catch is video display. Spending $300+ on googles is no way for me, and those cheap ones from hobbyking seem inferior to me - low res + blue screen of death. I'm checking RCMR web and youtube daily in hope of some fpv visor info .
I got pretty nice 3.5" 640x480 lcd from ebay, for about $17. After some testing by covering RX antenna with my hand to induce interference, I was surprised that LCD didn't turn off until whole picture went static with no recognizable image. It would turn right back on under a second, If I removed my hand from antenna. The only problem was it needs pretty clean signal to lock on sync and switch back on (Before you ask , yes I tried putting OSD between video RX and LCD - cheap one from hobbyking. The one thats in series with video line. Didn't work, OSD was barely visible on lcd and did't help in any way. If video signal was lost, OSD started blinking its red LED. Maybe paralell one would generate sync?). So I guess if I loose video at the distance, I'm done . But I think my CPL antenna setup will be more than enough for non-long range flights, under 10km.
After that tests, I bought some grandma reading glasses . Highest dioptre I could get was +4. Those allow me to get my nose 10cm from the LCD, but that is not enough. It would not fit inside any welding visor I tried at local shop . I'm thinking of some fresnel lens in front of lcd, but I'm afraid that it displays correctly only around ceter and distorts at the edges.
Another point - if I flip front visor cover with attached LCD up, I still have grandma reading glasses on my nose. And I can't see a thing with them on plus I get dizzy immediately
I wonder if we could brainstorm some ideas while Bruce is busy.
Richard
I got pretty nice 3.5" 640x480 lcd from ebay, for about $17. After some testing by covering RX antenna with my hand to induce interference, I was surprised that LCD didn't turn off until whole picture went static with no recognizable image. It would turn right back on under a second, If I removed my hand from antenna. The only problem was it needs pretty clean signal to lock on sync and switch back on (Before you ask , yes I tried putting OSD between video RX and LCD - cheap one from hobbyking. The one thats in series with video line. Didn't work, OSD was barely visible on lcd and did't help in any way. If video signal was lost, OSD started blinking its red LED. Maybe paralell one would generate sync?). So I guess if I loose video at the distance, I'm done . But I think my CPL antenna setup will be more than enough for non-long range flights, under 10km.
After that tests, I bought some grandma reading glasses . Highest dioptre I could get was +4. Those allow me to get my nose 10cm from the LCD, but that is not enough. It would not fit inside any welding visor I tried at local shop . I'm thinking of some fresnel lens in front of lcd, but I'm afraid that it displays correctly only around ceter and distorts at the edges.
Another point - if I flip front visor cover with attached LCD up, I still have grandma reading glasses on my nose. And I can't see a thing with them on plus I get dizzy immediately
I wonder if we could brainstorm some ideas while Bruce is busy.
Richard