Electronics (24)

M0RVB

Yet another project...

Note to self... stop collecting bits for projects and start building instead! Just in, this PCB and chip for the TARPN NinoTNC. Described as a multi-speed, multi-protocol USB-KISS packet radio interface this comes as a very nicely made PCB and PIC plus a bill of parts complete with Mouser part numbers and a spreadsheet that loads into Mouser to make a complete order. This will be a fun build. The TARPN website also has full ordering and step by step construction details. Neat!

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M0RVB

RF interference...

Tidying up the whole shack make life easier to reach stuff but did not completely cure one issue, that of RF flying about the place and getting into things where it was not wanted. I tried 10m this morning and two things happened. First, it set off the house alarm. Second, wsjt-x would not hold a tx cycle or tuning. The autotune was happy but that acts quickly. Using wsjt-x's tuning for a few seconds, or transmitting a CQ and the FT450D would tx, then off, then try again etc. This has happened before. First off, yes there is RF in the shack and it's due to the rather naff antenna wire in the loft. I need to live with that until I get some wire in the air outside. And yes, I've been saying that for ages! But before it was really down to the mass of cables all entwined and those have been completely tidied up now. So I was rather annoyed that the same issue has returned. And then I discovered that my attempts to dust round the desk had moved the serial cable between the FT450D and the Signalink and it was now laid across the…

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M0RVB

Zigbee randomness

Recently the outside lights here decided to switch off at random intervals for no apparent reason. There are 5 different controllers, two being Zigbee bulbs and the others Zigbee switches. All use 2.4GHz. All had been running reliably for maybe a year. On/off cycles are controlled by scripts on the server as well as manually via an app. In each case whichever set of lights had gone out did report as being off and would turn back on via the app. Some days there was no issue, on others at least one would go off at some point. The Zigbee bulbs never failed, just the switches. There was no evidence of any commands being sent to turn the lights off, but there was the occasional error being reported. Rebooting the server made no difference. A power cycle of the server seems to have cured the issue so I am considering it likely to be the Zigbee transceiver itself. This is now nagging at me to figure out what happened and presumably it will reoccur some time in the future. Too many other things to sort out though!

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M0RVB

Shack networking

It's surprising just how many things one gathers that need Ethernet. Having just made an NTP server out of a Raspberry Pi that took the last port in my 8+2 port PoE switch I needed more ports. The switch is a Netgear GS110TP, 8 Ethernet ports and up to two SFP modules for interlinking. So I have added a second GS110TP linked to the original one via a short fibre lead and two SFP transceivers. The house now has 4 Ethernet switches, all Netgear, making 48 Ethernet ports in total but not all in use, plus 3 wifi access points, Netgear again and all PoE powered. Actually I could have settled for a non-PoE switch as the additional one but this one came cheap, and new in box. All the switches and access points do SNMP too, centrally monitored using MRTG. Why? Because they can!

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M0RVB

Pi PoE

Still sorting the shack out today, hopefully two more days and it’s done. Today’s task was to fit PoE HATs to the two Raspberry Pi systems that run things like Pi-Star, the ADSB grabber and HamClock. These were both Pi 3B’s which do not have the pins for PoE - the 3B+ or the 4 does. So, first off, strip the cards out of the box. Not too bad. The first Pi 4 and its HAT was easy but the Pi Star one has the RF board. Installing the PoE HAT does not leave any of the Pi 4’s pins protruding. Fortunately I had a small stock of extenders, in fact, just enough. Not the neatest of constructions but it works. One thing caught me out though. The Pi Star Pi gets a static IP address via DHCP. When it booted up it would not let me connect or get to the web interface. A scan of the network found it and only then did I remember that, of course changing the card means a new MAC address! Anyway, both cards now have their MAC addresses in pi-hole (even though the IP is static doing it that way makes pi-hole…

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