I couldn't get GNU radio even to compile on my end, last I tried. That being said, it's clearly cool - it's being used of course by some hams this month to command ISEE-3. You can see their modulation scheme in GNU Radio here <http://www.jmalsbury.com/how-to-talk-to-a-36-year-old-space-probe-isee-3-with-gnu-radio-a-usrp-and-a-big-dish/>.
>From the article: "In these early days of deep space communication, the designers wanted to make the receiver on the spacecraft as simple as possible. Instead of designing clock recovery circuits on the spacecraft receiver, they decide to include the clock on the uplink signal. This is accomplish by AM modulating the FSK sub-carrier with the clock signal. Thus, there is now sub-carrier where frequency represents data, and amplitude represents clock. This FSK/AM modulated sub-carrier then phase modules the RF carrier (2.05 GHz). ". Phew! On Wed, Jul 2, 2014 at 6:15 PM, Guan Yang <[email protected]> wrote: > On Jul 2, 2014, at 17:56, David Reeves <[email protected]> wrote: > > That's pretty. I'll be at the space tomorrow, and happy to lend a hand > with any assembly and testing. > > > > Would you plan to stick to this power for the most part, or crank it > higher later? > > I plan to have higher power later, or figure something else out. The issue > is that we're dealing with a Chinese module that's not fully documented (no > block diagram for example). The transceiver IC itself is powered at 1.8V > and various low voltages, fed by a series of LDOs. I don't know the voltage > of the external power amplifier. The datasheet says they recommend powering > at 5V. My guess would be that the PA operates directly at 5V. > > 5V should be easy with USB power, but since the microcontroller is at > 3.3V, we would need annoying level shifters. > > When we start powering things from a battery, this implies two switching > regulators, one to boost to 5V, and another to buck/boost to 3.3V. Or > operate everything at 3.6V, a little above the module's minimum. Or just an > LDO for the 3.3V. All of these take up valuable space on the board. > > Konstantin is working on his own RF design using a Silicon Labs chip > that's similar to the one on the module. It might be cheaper. These modules > are about $10 apiece. > _______________________________________________ > Radio mailing list [email protected] > https://list.hackmanhattan.com/listinfo/radio >
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