I bought the SUP500F from SparkFun and according to the specs the Venus645FLPx is supposed to have a hot start open sky acquisition time of <1s. It seems to be taking 30 seconds on my hardware whether I do a hot start or a cold start. I’ve got a battery backup and the real time clock and SRAM seem to be maintaining values over power down, but the the acquisition time still seems long.
Has anyone gotten this chip to do a fast hot start? Did you do anything special to make it work?
teekay_tk:
i get about 2-3 seconds with antenna in a wooden shed. dont do anything facny, try to see if the battery backup line actually does have voltage on it.
Thanks TK. Which Venus are you using? Since the SUP500F has a chip antenna I’m guessing you’re using a different model, but they should act the same. I just have to keep debugging, but at least I know what to expect.
aha, I am using my own desing. But I really hate any design that uses a patch antenna without a substancial ground plane. in my eperiments a ground plane is very important and most patch antenna reference desighns use it
teekay_tk:
aha, I am using my own desing. But I really hate any design that uses a patch antenna without a substancial ground plane. in my eperiments a ground plane is very important and most patch antenna reference desighns use it
Not knowing anything about RF design (heck I don’t know that much about electronics in general ) I went for the easier choice and used something with the antenna built in. I heard it was good to avoid traces under the chip, so I masked them out on my PCB, but I have no idea how well the RF portion is designed.in the SUP500F.
) I went for the easier choice and used something with the antenna built in. I heard it was good to avoid traces under the chip, so I masked them out on my PCB, but I have no idea how well the RF portion is designed.in the SUP500F.