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An open-source 240-antenna array to bounce signals off the Moon

moonrf.com

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Re: An open-source 240-antenna array to bounce signals off the Moon

#12

Post by jowelene »

HNisCIS wrote: post #4
infinitewars wrote: post #2

Wild hardware flex for a garage project. Reverse-engineering the Pi 5's MIPI to push 5.6 Gbps from custom MASH sigma-delta ADCs to a Lattice ECP5 FPGA to the Raspberry Pi is serious engineering. The idea that the RF receiver looks like a "camera" to the Pi while the transmitter is a "display" is super creative. Getting a 1.5 kW, 240-antenna EME array for $2,499 is actually cheap for something like this. Their standal…

I'm struggling to understand the signal chain or antenna architecture here. If those two MAX chips are 2829s this would be 2x2 mimo per tile but I'm not super familiar with that product line and the PCB layout looks like a 4x4 setup. And yeah, the agentic stuff is dumb, I've played a ton with doing low level SDR work on Opus 4.6 and it's truly ass. Also, the "can't radar, plz don't ITAR" is horseshit. Some basic fw t…

MAX2850/2851 4x4. Also, large radar stuff is more nuanced than "just some fw tweaks" as you claim. Same as Facebook is not just some PHP scripts...

Re: An open-source 240-antenna array to bounce signals off the Moon

#13

Post by Terr_ »

diimdeep wrote: post #3

Cool, how full array compares to the single antenna placed on Starlink satellite ?

How would that be a useful comparison? Aren't the use-cases too different?

Not only is the moon >100x farther away (even accounting for near-horizon satellite angles), but you're also trying to bounce a signal off it as a passive reflector, which is harder than just transmitting something an active lunar receiver could detect and re-transmit back.

Re: An open-source 240-antenna array to bounce signals off the Moon

#14

Post by mschuster91 »

> The target launch price is probably ~$399 (dependent on the tariff landscape over the next month). For that you get the QuadRF tile, an included Raspberry Pi 5, the custom case, tripod, USB-C power supply, cables, and a pre-loaded SD card with a ton of cool SDR applications.

Meanwhile... the RPi alone will probably make up 299 dollars of that price tag [1].

It is not a good time to design hardware that needs RAM. Arrest and imprison Sam Altman.

[1] https://www.jeffgeerling.com/blog/2026/dram-pricing-is-killi...

Re: An open-source 240-antenna array to bounce signals off the Moon

#19

Post by Neywiny »

infinitewars wrote: post #2

Wild hardware flex for a garage project. Reverse-engineering the Pi 5's MIPI to push 5.6 Gbps from custom MASH sigma-delta ADCs to a Lattice ECP5 FPGA to the Raspberry Pi is serious engineering. The idea that the RF receiver looks like a "camera" to the Pi while the transmitter is a "display" is super creative. Getting a 1.5 kW, 240-antenna EME array for $2,499 is actually cheap for something like this. Their standal…

While true I do worry that it's mandating a pi 5 for each tile? And who knows how specific it is to the 5. Doesn't seem very open relative to something like a usb superspeed, pcie, or 10gbe. USB could be maybe done with the LIFC-33U depending on I/O limitations. PCIe can be done on various FPGAs in the lattice lineup and others.

If you use PCIe, theoretically you don't need to reverse engineer how they implemented because you're not at the edge of the spec like they are here.

That said, I've thought about doing what they're doing countless times and it is nice to see it would work.

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