For info, Airspy currently have a 15% off sale on their products. So if you were thinking about getting one, now may be a good time. I have just ordered an R2 to go along with the mini I already have, not sure how much (if any) performance increase it will give, but I can use it to replace the Blue flightaware stick that one of my systems currently uses.
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They are better in many ways. They have a greater dynamic range. That means they can hear louder and quieter signals without changing the gain settings. The metal case provides better noise shielding.
I found their performance close to a radarcape or airsquitter.
The downsides are that they generally require a pre-amp, they are a little deaf at 1.2ghz and use a lot more CPU.
I have several and they work well.
I have never managed to get them to work for UAT 978Mhz. I tried a few years ago but never had any luck.
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Hi Jon,
I’m planning on replacing my Pi 4 with a Pi 5 so that I can add a Nooelec V5 for ship tracking to the Airspy Mini I currently use for adsb.
The Pi 5 has a USB current budget of 1600mA while the Pi 4 is limited to 1200mA. I’ve been testing the v5 with a Pi 5 running Ais-catcher, and it draws about 290mA, with the LNA/Filter adding another 50mA - so in theory the extra 400mA available from the Pi 5 will cover the ship tracking hardware, and the Airspy Mini shouldn’t be affected.
Seeing your comments makes me think that maybe I could replace the Mini running at 20 MSPS with an R2 running at 24 MSPS. What sort of current draw do you see with the R2?
Processor load shouldn’t be an issue - The Pi 5 with Air-catcher and an instance of readsb taking data from my current feeder has an over CPU utilisation of less than 2 per cent.
Thanks, John
Yep, looking at my Flightaware stats my Airspy mini gets about 25% more Positions Reported and about 10% more Planes Reported then the Blue Flightaware stick (both being feed from same aerial, LNA, splitter). I was wondering what improvement I may get from the R2.
I have a Pi 5 I got when they were released, but haven’t used it yet, so wondering if I should use that for the R2, or if it will be over kill and just use a spare Pi 4 I have. The Airspy mini is on a Pi 4, and it runs fine (CPU wise), apart from I set it up to run off a USB SSD, and I get MLAT dropping out now and then, and I assume it’s because the USB port bus is overloaded, so not sure if the Pi 5 would help with that issue.
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If you aren’t already aware, the extra USB current is only available when using the official non-standard pi power supply. It uses 5V 5A by USB-PD, which is not a standard PD output mode. A normal 5V 3A psu will only allow 600mA for USB devices.
The other consideration with USB is bandwidth. The pi 4 only has 1 USB 2 controller so all devices must share the bandwidth and an airspy uses practically all of it.
The pi 5 is much better in that regard. It has two separate controllers, one runs the top ports and the other the bottom. Additionally each controller should be able to support 2 full speed usb 2 data streams, so running multiple airspies becomes a possibility along with usb attached storage without them disrupting each other.
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What are the USB current restrictions when using PoE+ with a RPi5?
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Thanks @caius, that is very useful information that I hadn’t read deeply about the Pi 5 to discover. Without knowing this, I probably would have put the Airspy on the USB 3 bank and the V5 on the USB 2 bank - so good chance they would have ended up on the same controller.
I was aware of the issues around the Raspberry Pi non-standard PD supply - they do provide a way around this.
@tech0 I’m powering my Pi 5 with a Waveshare POE HAT
https://www.waveshare.com/product/raspberry-pi/hats/poe-hat-f.htm
This is an 802.3at POE device that can supply up to 25 watts through the HAT (If I’ve interpreted the spec correctly, a maximum of 22.5W is available to the Pi). When first installed on the Pi 5, the HAT isn’t recognised as a high power supply and the USB power output is throttled to 600mA. You can check this with the following command and response:
jrg@pi51:~ $ vcgencmd get_config usb_max_current_enable
usb_max_current_enable=0
To enable 1600mA mode edit config.txt:
jrg@pi51:~ $ sudo nano /boot/firmware/config.txt
Add the following line (I put in under the [all] heading, though strictly it should be under a Pi5 section)
usb_max_current_enable=1
Save and reboot the Pi 5 for the change to take effect. Run the vcgencmd command again to check.
Another potentially interesting Pi 5 command is vcgencmd pmic_read_adc
I haven’t investigated the output in detail but wonder if one of the current readings might relate to USB load?
I’ve had a good experience with a Waveshare 802.3af POE HAT on my Pi 4 Airspy Mini feeder - it has been running continuously since March 2023 without issues.
I don’t think there is any way for the Pi5 to detect the capacity of a PoE hat, so it’s up to you to set the high power flag if you need it. When it negotiates the 5A supply itself via USB-PD it can do so automatically.
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@JRG1956
My 4’s and 5’s all have Waveshare PoE+ hats. The 5’s have a cooling fan built into the PoE+ hat. I use a home made Pi Rack open on the sides with a mounting plastic plate for each Pi instead of a case.
@caius
The 5’s have a raspi-config setting to disable USB current limit.
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Just purchased a Airspy mini… Needless to say, its different. Not having any issues on a PI4 8gb, with a FA 1090 band pass. Curious to find out all of the different settings everyone is using. VERY different with putty/piaware. What does everyone’s airspy mini setups look like (filters, LNA’s, antenna etc). Still fairly new at this. so any help would be greatly apricated.
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