I don't think you should call something 'open source' until you've released the source, but other than that this is an extremely impressive project. HAM's have been doing EME since forever (https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Ear... ), it is a very neat trick.
It almost looks as if the EME bounce capability of this antenna is a fig leaf or an afterthought, my own 'applications' list would be a lot of things, but not that.
Apparently it’s a way to attract attention and support. I’ve been following picoIDE which got some attention here on HN 4 months ago [1]. When asked then where the src is, the answer was in a few weeks. Fast-forward a crowd-supply campaign (no mention 4 months ago) to the tune of 350k and the repo is still empty.
You can find all the software there (for every demo shown on the website), but it's not "build-ready" given the hardware isn't released yet as the website makes clear. The repo is from last year but not generally advertised.
I suppose HN picked up on this project again because of the moon mission this week.
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 standalone 4-antenna tiles (https://moonrf.com/updates/) show off some killer apps, like 30 fps spatial RF visualization and NEON-optimized drone video interception.
I'm rolling my eyes at the "Agentic Transceiver" part, though. It is highly doubtful that an onboard AI casually writes, debugs, and compiles a real-time C app with analog video color sync recovery and decode in ten minutes.
> 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
Using video interfaces to transfer arbitrary data at high speeds is becoming a common trick for cheap boards with limited interfaces. Video inputs and outputs are generally highly mature and optimized to avoid dropping frames because everyone wants reliable video. Putting arbitrary data into video IO pipelines is a cheap way to get high speed IO through standard interfaces.
There is a cool project that uses cheap HDMI to USB capture devices for high speed data transfer out of cheap FPGA boards that have HDMI output [ https://github.com/steve-m/hsdaoh ]
In a perfect world, using PCIe directly would be a much better solution for a project like this. Having access to PCIe DMA support directly without relying on video IO peripherals is helpful for high speed ADC/DAC applications like this. It would also make the board more portable to other SBCs.
The ECP5-5G can do PCIe 2.0 x2 or PCIe 1.0 x4 which would provide around 8Gbps of data transfer. The problem is that the Raspberry Pi 5 only exposes a single PCIe lane to the user. The other 4 PCIe lanes of the Raspberry Pi 5 SoC are routed to the RP1 chip, which has the MIPI and CSI interfaces that are used in this project. So the data is going through a convoluted path instead of being connected to PCIe directly.
I would have to look at the details more closely, but even using the PCIe 2.0 x1 port (around 4 Gbps after overhead) on the Raspberry Pi would be close in bandwidth to the 5.6 Gbps number they give for their custom MIPI solution.
I think the Raspberry Pi 5 is a good first choice for most projects because it is widely support and has the largest community, but for a project like this the benefits of moving to a different SBC with PCIe 2.0 x2 would have been helpful. Keeping the project semi-independent of the SBC has a lot of benefits.
unfortunately the ECP5-5G FPGA (with the SERDES/PCIe option), costs way more than the ECP5 (without SERDES). The Pi-5's MIPI interfaces gives you 8 parallel LVDS lanes that can run at 640 MHz each which is manageable for a cheap FPGA.
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.
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 tweaks and you could get this to be, at the very least, a sweet FMCW setup.
For context, the same phased-array transceiver technology is used in Starlink terminals, some of which have 1,280 active elements. Such a terminal can require as much as 150W to function.
It's also why pictures of modern naval vessels show flat panels instead of rotating parabolic antennas as in past decades. The panels contain advanced phased-array radars.
Pretty cool. And expensive. It's pretty amazing how starlink sells basically this for $200. Pretty sure they subsidize it.
Ps you don't really need this. A phased array is great for communicating with or tracking fast moving objects. For something as slow as the moon a simple parabolic dish, either manually aimed or with an az/el motor will be more cost-effective. Motors get expensive too with wind and rain and longevity (moving around 24/7) but hams don't moonbounce constantly.
Starlink sats move really quickly through the night sky and it tracks multiple so you don't have interruptions this is why for that purpose a phased array is great. For incidental ham use to the moon it's very interesting tech but not exactly necessary.
EME has been made a bit more affordable and effective by weak signal modes and DSP.
It used to require very high power, expensive transmission lines, preamps and monstrous arrays of Yagis. Now with JT65x, and SDRs, you can use cheaper coax to get transmit power to the antenna eating that loss with more RF, and put SDRs for RX at the array. People running digital modes are getting away with needing less gain.
5650MHz is the only place to do it with this thing. Might want to break out a calculator before the credit card because path loss has to be more than 285dB. But if you can swing it, might want to buy two so you have someone to talk to. I have not heard anyone using 5650.
> 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.
This is brilliant, but on a less than brilliant internet connection like mine the site images are loading at a snails pace. Maybe use WebP rather than png?
69 comments
It almost looks as if the EME bounce capability of this antenna is a fig leaf or an afterthought, my own 'applications' list would be a lot of things, but not that.
[1] https://news.ycombinator.com/item?id=45949352
I suppose HN picked up on this project again because of the moon mission this week.
It was discussed a few months ago: https://news.ycombinator.com/item?id=45790672
You have to understand this is a relatively sleepy personal project at this point still.
Their standalone 4-antenna tiles (https://moonrf.com/updates/) show off some killer apps, like 30 fps spatial RF visualization and NEON-optimized drone video interception.
I'm rolling my eyes at the "Agentic Transceiver" part, though. It is highly doubtful that an onboard AI casually writes, debugs, and compiles a real-time C app with analog video color sync recovery and decode in ten minutes.
> 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
Using video interfaces to transfer arbitrary data at high speeds is becoming a common trick for cheap boards with limited interfaces. Video inputs and outputs are generally highly mature and optimized to avoid dropping frames because everyone wants reliable video. Putting arbitrary data into video IO pipelines is a cheap way to get high speed IO through standard interfaces.
There is a cool project that uses cheap HDMI to USB capture devices for high speed data transfer out of cheap FPGA boards that have HDMI output [ https://github.com/steve-m/hsdaoh ]
In a perfect world, using PCIe directly would be a much better solution for a project like this. Having access to PCIe DMA support directly without relying on video IO peripherals is helpful for high speed ADC/DAC applications like this. It would also make the board more portable to other SBCs.
The ECP5-5G can do PCIe 2.0 x2 or PCIe 1.0 x4 which would provide around 8Gbps of data transfer. The problem is that the Raspberry Pi 5 only exposes a single PCIe lane to the user. The other 4 PCIe lanes of the Raspberry Pi 5 SoC are routed to the RP1 chip, which has the MIPI and CSI interfaces that are used in this project. So the data is going through a convoluted path instead of being connected to PCIe directly.
I would have to look at the details more closely, but even using the PCIe 2.0 x1 port (around 4 Gbps after overhead) on the Raspberry Pi would be close in bandwidth to the 5.6 Gbps number they give for their custom MIPI solution.
I think the Raspberry Pi 5 is a good first choice for most projects because it is widely support and has the largest community, but for a project like this the benefits of moving to a different SBC with PCIe 2.0 x2 would have been helpful. Keeping the project semi-independent of the SBC has a lot of benefits.
> Using video interfaces to transfer arbitrary data at high speeds is becoming a common trick for cheap boards with limited interfaces.
There is a line in the book Accelerando about how evolution did this with biological vision.
It's basically the highest bandwidth sense we have and evolved AFTER smell (chemical based) and auditory (gas pressure based) senses.
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.
> 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.
In the multi-tile array it apparently still only needs one Pi [1] as the FPGAs do the heavy lifting.
[1] https://moonrf.com/updates/
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 tweaks and you could get this to be, at the very least, a sweet FMCW setup.
> Getting a 1.5 kW, 240-antenna EME array
It says 1W TX power per antenna. So the 240 antenna array which draws 1500W has a transmit power of 240W.
https://news.ycombinator.com/item?id=45790672
It's also why pictures of modern naval vessels show flat panels instead of rotating parabolic antennas as in past decades. The panels contain advanced phased-array radars.
Ps you don't really need this. A phased array is great for communicating with or tracking fast moving objects. For something as slow as the moon a simple parabolic dish, either manually aimed or with an az/el motor will be more cost-effective. Motors get expensive too with wind and rain and longevity (moving around 24/7) but hams don't moonbounce constantly.
Starlink sats move really quickly through the night sky and it tracks multiple so you don't have interruptions this is why for that purpose a phased array is great. For incidental ham use to the moon it's very interesting tech but not exactly necessary.
It used to require very high power, expensive transmission lines, preamps and monstrous arrays of Yagis. Now with JT65x, and SDRs, you can use cheaper coax to get transmit power to the antenna eating that loss with more RF, and put SDRs for RX at the array. People running digital modes are getting away with needing less gain.
5650MHz is the only place to do it with this thing. Might want to break out a calculator before the credit card because path loss has to be more than 285dB. But if you can swing it, might want to buy two so you have someone to talk to. I have not heard anyone using 5650.
> 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...
> Power Supply: 12 V DC (≈1.5 kW peak)
That's a lot of juice for 12VDC
or does it still need industrial grade lasers?