Introducing Dreamcatcher - see picture!

A fully integrated SDR receiver. Includes the following features (@Abhishek @zoltan: please edit/update this list). Be the first to find out when it is available: http://eepurl.com/Tp87T

  • L-band SAW filter (1525 - 1559 MHz)
  • Two-stage L-band LNA with 34dB gain
  • 0.5 PPM TCXO
  • RF bypass for tuning from 24 - 1600 MHz - use as a regular RTL-SDR!
  • USB ports
  • GPIO forest
  • UARTs, I2C, SPI headers (unpopulated) for driving external hardware
  • Two microSD card holders - for boot and storage!
  • 1 GHz CPU
  • 256 MB RAM
  • USB wifi dongle (not shown) - AP mode capable!
  • Lots of LEDs! and Switches!
  • microUSB OTG
  • microUSB power port
  • Audio In/Out
  • Speaker with 1.4 W integrated audio amplifier
  • Fully mainline (4.10) Kernel and (2017.01) Uboot support!
    *** JST battery is being removed

On the Roadmap:

  • armbian/debian support

This is a fully-integrated SDR receiver - RF frontend, SDR, Compute, Wifi - Everything!

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This is what we need - - looks to be about 2 times the size of a CHIP with great features. We’ll all standby for ordering instructions. Ken

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Where can we order this?

Have you guys considered adding a voltage regulator to support a wider range of voltage? I could see that causing noise though.

@demandzm That’s exactly why @zoltan killed the voltage regulator. We may get clever about it in the future, though.

@on4bgc We are almost ready for production. Parts are getting pipelined as we speak, but we did run into one design problem on this rev2. After confirming rev2.02, we’ll be ready for production. Fingers crossed for the second week of April.

@kenbarbi It is substantially larger than CHIP. The board is 120mm x 120mm. About the size of a DVD case.

It’s even bigger that the SDRx and CHIP together…and has no wifi and only 256MB Ram instead of 512MB.
Also there is no ROM that is much faster than a microsd card.

Sorry, but i don’t really understand what the point is.

Chip + SDRx seems to be a better deal doesen’t it? Will it replace the SDRx? Or is it only used in the Lantern?

regards,
Manuel

I thought that would be the case. For now I will stick with my buck converter for camping trips. :slight_smile:

We are using a standalone wifi dongle because of all of the wifi problems we’ve had on the CHIP. Speaking of, let me know if you can find any CHIPs :wink:

For our application, this meets our needs. Of course, for general purpose computing, it may not. This will replace SDRx. Our path has been to integrate as much as possible–and have more control over our supply chain.

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bigger, yeah: single sided component placement with bunch of connectors, gpio forrest, LEDs, etc. It’s more like a unique SDR development board then a final, compact product now. Look the bright side of this, possibly much less heating issues compared to tiny CHIP :slight_smile: (more heat dissipation area)

256 MB RAM can substituted with 512 MB any time during production

Yeah, NAND faster then micro SD card, but who cares? :smiley: it’s not a video processor board so quality SD card should be fine ever. The main reason for microSD is that it is easier for people to flash than FEL process. We had other technical issues which influenced this decision, so not coincidence.

As @Syed said, CHIP is not very easy to come by.

2 Likes

I see a lot of potential here, even outside of outernet.

A few thoughts:

  1. Get a thermal camera on that prototype ASAP.
  2. It looks like your microSD card ports stick out too far. I assume that the enclosure will be flush with the collar on the audio jacks, and the edge of the microSD port sticks out to about the far edge of the jack. That means that the microSD will be hanging outside the enclosure a bit, and it’s easy to damage this way.
  3. Same thing on the left side of the board, if you want your USB jacks to be accessible from outside an enclosure then you should pull back the battery connector or put it on another edge (unless you mean to have an external battery?).
  4. Maybe can eliminate that AMS1117-3.3 by just using the AXP209’s 3.3V regulator?
  5. Why two RF inputs? You could use a GPIO off of the processor to switch between an LNA bypass or not.
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We have an L-band SAW filter that the bypass can avoid.

To clarify - - the Dreamcatcher at 120 x 120 mm is the size of the Patch antenna. Based on your comment about heat, it looks like one could stack the Patch, Dreamcatcher, and Lipo in a smaller enclosure (or add the Dreamcatcher to the current Lantern enclosure).

I see the JST power plug so I presume unit can charge a Lipo and work off external ac for awhile as the current CHIP does, Ken

  1. Why do you think it has thermal issues? You mean the SDR or the digital section? The digital area is 5 times bigger then CHIP area, so pretty good surface for heat dissipation with paying attention for exposed pads.
    We “hand scanned” the first working prototype board btw and was okay so far :slight_smile: Will eager to get more feedbacks once of course!

  2. SD cards will be okay with the case according to the datasheet. The audio jack will sit a bit deep, will need to solve that with the enclosure design (once we have everything), audio jack cannot pushed more to the pcb edge unfortunately…

  3. LiPo is just a evaluation feature now, will disappear as makes no sense here with actual energy budget.
    Bigger problem is the micro USB which sits much deeper then other components have to work on that also when mating with the case.

  4. Yeah, I was thinking of that but finally left it there to avoid connecting noisy digital VDD to the sensitive radio parts. Hopefully the LDO smooths out some ripples, this can be tested later. Also not to mention that now instead loading AXP209 + 3.3V DCDC regulator we have an independent LDO driven by the USB 5V, hopefully augmenting lot’s of CHIPs power outage issues caused by overloads.

  5. For having single RF port and two RF chain we would need 2 RF switcher (now using 1). Not to mention that that case an RF switch would sit on the top of the RX chain degrading the NF of the satellite receiver chain as the first stage dominates that. Bias tee would be also more tricky.

Thanks for the valuable comments!

I would definitely use 512MB RAM in the final product.
If the Dreamcatcher has no heating issues like the CHIP, that would be really nice.

@Syed I would also like to know where to get a second CHIP :wink:
But inbuilt WIFI is a must in my opinion. I also never had a WIFI issue with the CHIP so far.
Also will the USB dongle be in the kit from you?

Is there already a estimation on MSRP?

regards,
Manuel

@zoltan Already hit on it, but NTC has shown troubles keeping the supply chain going for CHIPS. To me it seems they may already be moving on to other projects. Also they still seem to ship each CHIP individually from Asia, which it would make much more sense to send batches back stateside and send them out from NTC HQ, one would think anyway.

I think that the problem is the shipping.

If you chip each individually, you have eventual less Shipping cost (Chinapost).
But you definitely have not pay tax or custom dutys, what is a problem in the US and EU.

If you ship a whole batch, you will need to pay these taxes and dutys.

regards,
Manuel

The R820T2 (if that’s what you have under the can) produces a ton of heat. You lose a lot of sensitivity if it’s overheating. Also since it is covered with the metal shield, the only way to keep it cool is via the PCB. So you may want to verify that what you’re doing is working. If the IC is staying below 180F while operating then you’ve done a really good job of dissipating the heat via the PCB. See here for some sample measurements that I made with a FLIR E8. These were done on the “nano” sized R820T2 dongles with less area, but the idea still holds.

Very nice measurements, thanks for sharing!

We testing the SDR section since a relatively long time on different prototypes of SDRx, that was copy pasted into the Dreamcatcher board. The shield shouldn’t cause issues as not the IC package dissipating most of the heat but the exposed pad guiding it to the solid copper poured GND layers (4 layers) and that copper layers does the heavy lifting of the heat transportation all around the PCB. BTW the shield has venting holes now, this might change.

Once I’ve done single point heat sensor measurements using multimeter, can reproduce it for you while start evaluating DC. Thanks for noting this, we know it’s can be a real issues, more often seen on L-Band operation of rtlsdr.

One more thing. I’m not sure the details of your CHIP power issues, but we had them also when trying to drive an SDR and charge the LiPo. It was easily fixed by changing the AXP209 load sharing settings.
See here.
Simple fix in our case.