Dreamcatcher - ethernet via SPI?

Any thoughts on using an ethernet module such as an ENC28J60 via one of the SPI connections on the Dreamcatcher v2.03? Could the 3.3V connection from the TWI2 or UART be used, or would I be better to tap that in from elsewhere on the board?

I’m not looking for anything high bandwidth, just ssh and command line for installing and configuring software. I know that the rtl8188 wifi and usb ethernet are good options. I was just curious about using the SPI.

It looks like the DC2.03 has two SPI ports – SPI1 and SPI2.
Each device on a SPI interface typically needs its own Chip Select.
I’m a bit concerned that both ports refer to the same CS0 signal.
I did not ohm it out to see if that CS0 is shared with anything else.

I think you should be able to get a driver for the ENC28J60 under ARMbian. It’s quite common.
Armbian supports an Ethernet adapter with DHCP and SSH server ready on default port (22)
I’m not sure though if that driver depends on an interrupt line.

I think building a little daughter board that connects to one of the two SPI ports should work.

UART1 or TWI2 both have a 3.3v connection. I don’t think an Ethernet module is going to draw that much. The modules are $4 on E-Bay. I would definitely try it. If you can get at the other four pins on the Ethernet side, you may even be able to build a PoE DreamCatcher.

–Konrad, WA4OSH

Just curious: Why are you not using the built in WIFI of the Dreamcatcher?


Sometimes Wi-Fi does not have the reach that Ethernet does. Ethernet can go 328 feet, realistically, for Wi-Fi this is a stretch. Sometimes, Wi-Fi comes with a lot of interference such as apartment buildings where everyone and their brother is on Wi-Fi, all occupying the entire bands to ensure they get much more bandwidth over the air than they get from their ISP. Sometimes it’s easier to locate the receiver closer to the antenna/LNB, etc. I don’t know what Nate’s reasoning for needing Ethernet is.

–Konrad, WA4OSH

@Nate You might want to comment on this.

@Tysonpower Admittedly, tinkering and learning are a big part of why I’m attempting to add ethernet. I do also live in an apartment and generally don’t set up wifi on devices unless or until I have a need to do so. Though, I do think that the wifi included with the dreamcatcher would be best for most uses.

@Konrad_Roeder Thanks for the input. I’ve ordered a couple of the ENC28J60s (I’ve meant to pick up a couple for use with arduino and RPi clones, anyway). I’ll try to post the results once I actually connect things up. Regarding the CS0, even if they were shared on both SPI ports, it’d only be an issue if I actually tried using both, right? Though from what I can tell, the CS0 trace on SPI2 appears to lead straight to one of the pins on the A13.

– Nate, KE0PFS

@donde You are welcome. :wink:

@nate and @TysonPower Something I did not mention before: At 1.5 GHz, the losses are in the neighborhood of 10dB per 100 feet. What this means it that the bare LNB can’t be very far from the receiver. Ethernet can be extended in many ways. It can overcome the horrendous losses over coax.

@Nate Yes, I did not ohm it out. But it looked like CS0 on both SPI ports were connected together. It does not matter unless there’s another SPI device using CS0. I don’t have a working DreamCatcher anymore. But if that CS0 is already being used for something else we’ll have a problem. Each SPI device needs its own chip select.

As an aside, I2C uses addresses, so many devices can share an I2C bus.

My other concern is that the driver may be interrupt driven. I have not looked at the ENC28J60 code to tell you.

– Konrad, WA4OSH

Good Morning all. I still see the Outernet beam loud and clear. Tomorrow is the 16th and “Good Night” for Outernet on L beam. I wonder what we might see in place of it? Soon we hope to see our Outernet riding on a Ku beam. And delivering news and data at 10 times the speed. GO TEAM!

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