Pluto+ versions

[haywardperson]

I want to thank you Paul for going to the trouble of sharing this project with us. It is very exciting and I can't wait to get started. Trying to choose which of the many Pluto+ versions for sale on Aliexpress. There is a large price difference between them. In doing research I found one message thread on AMSAT-DL that the newer versions, without the "Pluto+" silkscreened on the circuit board were not reliable. Any thoughts on what version to buy to have a successful build?
Also when Matt did a number of videos of using the Pluto+ he had to use filters, preamp, amp etc to create a usable transceiver. Would you recommend following his Langstone build and using the same setup for completing the SDRberry as a full transceiver? If I use the Compass Express can the buttons be programmed for useful functions on the SDRBerry?
Thanks very much!!

[paulh002]

Hi,
I don't have experience with the Pluto+. I only have an older model Pluto, I was also checking for a Pluto+, but have bought some other SDR's because there are several users with SDR+ and HackRF. But I am still interested in the Pluto+. From a software point of view there is no difference. Regarding the Compass Express I don't know the device, or are you referring to the Contour Express? Those buttons can be used, right now they are hardcoded but that could be changed and made more configurable. With regard to the filter selection Sdrberry supports I2C for configuring filter settings. You can specify the I2C commands for every band. It should not be a problem, It supports some common I2C GPIO chips, and if the one you are using is not supported it can always be added. I would first before building a complete set try to connect Sdrberry to the Pluto+ and see if everthing works as expected. Some people did a lot of testing with HackRF for the UHF bands and the gave me a lot of feedback. We can do the same for the Pluto+. Just let me know.

73,
Paul

[haywardperson]

Thank you so much for your reply Paul. Yes I meant the Contour Express :)
Ok, great. So I will first set everything up with the SDRPlay to get the system basically working. Then I think I will choose one of the original Pluto+ with that label on the circuit board.
Thanks again

[haywardperson]

I just got everything working with the SDRplay, sort-of since I don't have the 7" rpi monitor yet nor the Pluto+, on an hdmi monitor. Looks GREAT.
So if I may ask a question while I am waiting for the new hardware... Please if this question is too basic just let me know.
I am not familiar with your use of the term " I2C for configuring filter settings". I am used to using I2C bus devices building drones, like GPS modules etc. So I am guessing that you support I2C devices that could be like a external GPIO card that would then control the switching of various filters for the different bands. Am I understanding correctly or are there actual I2C connected filter modules that you communicate with I2C commands directly?
Thanks for your time.

[paulh002]

Yes, correct. You have GPIO chips like PCF8574 which has 8 I/O 's combined with a relay driver like ULN2003 you can switch filters. I don't know if there are commercial available or kits for the specific frequency you want to use. Because higher frequencies are a bit special. You can also use solid state RF switches like AS169 which can switch till 2.5 Ghz. Best to ask some people who have experience with this kind of technique.

[haywardperson]

Got it, like this https://m0xpd.blogspot.com/2014/01/low-and-band-pass-filters.html

[haywardperson]

Just wanted to add to this discussion what I have found out about the Pluto+. The original version has the words "Pluto+" silkscreened on the circuit board. It also has a metal can covering parts of the RF circuitry. There are a couple of reports that the newer version, made by another company than the original Pluto+, does not work as well and has problems. Reported by Matt at Tech Minds and two others. I bought mine from Hackgeek.

[haywardperson]

Paul, Another question you may not be able to answer because you don't have a Pluto+ but...
Unlike the original Pluto the Pluto+ has an ethernet port built in. It makes sense to mount the Pluto+ and all the filters and amplifiers in a box at the antenna. So it also is attractive to use POE to piggy-back the dc power for the devices over an ethernet cable and use the Pluto+ via ethernet. But there is something strange about the PLUTO+ config.txt. There are two places for ethernet addresses with the second called [USB_Ethernet] which is the one several projects use. One QO-100 user uses a USB ethernet adapter even tho he has a built in ethernet port on his laptop and connects instead using the USB-ethernet adapter to the Pluto+ ethernet connection.
So the question is if the Pluto+ is connected via ethernet, to the RPI4, rather than USB will the SDRBerry software find the Pluto+ or does it only look for USB connected SDR's.
Thanks

[paulh002]

Its not sdrberry that communicates with the Pluto+, but the SoapyPlutoSDR driver. The SoapyPlutoSDR driver uses the analog devices libiio driver to connect to the Pluto. So the question is can SoapyPlutoSDR support the ethernet port on the pluto+.
I don't know, but you could ask on the github page of SoapyPlutoSDR. https://github.com/pothosware/SoapyPlutoSDR

A tip can be that you can change the probe value

[probes]
hifiberry = "driver=hifiberry"
pluto = "driver=plutosdr,hostname=192.168.100.1"
radioberry = "driver=radioberry"
rtlsdr = "driver=rtlsdr"
sdrplay = "driver=sdrplay"

Change the ip number of the pluto to the number of the ethernet port. 192.168.100.1 is default for the USB port. This would be my guess

[haywardperson]

Got it. It looks like SoapySDR depends on libiio and it says:
"ou can use libiio natively on an embedded Linux target (local mode), or use libiio to communicate remotely to that same target from a host Linux, Windows or MAC over USB or Ethernet or Serial."
But if I am not understanding I can still use USB-Ethernet converters on both ends.

[haywardperson]

Shouldn't you be asleep :)

[paulh002]

Yes, I should

[haywardperson]

Also could you be so kind and glance at my diagram and see if it looks like I have a grasp on the project since I have never done anything like this before?

[haywardperson]

Please excuse my American humor. I know insomnia is trying. I hope you find a way to get the rest you need.

[paulh002]

Did not know Americans have sarcastic humour, always thought this was a tipical Dutch trade. But luckily I manage to get some sleep, thanks

[haywardperson]

Not so much sarcastic as a feeble attempt to lighten the mood. I understand how difficult it can be not to be able to sleep.

[paulh002]

Thanks, don't want to turn this thread in to a medical discussion, but I can sleep but are waking up a lot due to the "old man disease" so to say. Which has turn bad. The nightly distraction is sometimes welcome. Next year January I will be out of action for a while, hopefully it will be fixed. Luckily no healthcare insurance issues over here. Have a merry Christmas and happy new year, cheers Paul

[haywardperson]

I understand completely. It is only sane to have basic health care for all.
So that is good and medicine gets better every year.
Happy Holidays to you too!