Radio and rails...

M0RVB

Nextion displays and memory sieves

You know the phrase 'memory like a sieve'? Well, that's mine. I just received a 3.2" Nextion display via Aliexpress which arrived after only a few days from China. This was to be a display for the M17 hotspot. But there were a few unexpected hurdles! First off, I could not remember the connections from the GPIO pins of the Pi to the Nextion. It's actually really easy, pins 4, 6, 8 and 10, but it took me an age to find that information on the web. Onthe Pi 4B the GPIO pins are numbered from the top (the opposite end from the USB and Ethernet connectors) with odd numbers on the left and even on the right. There are plenty of diagrams on the web. So pin 4, which is +5V is the second one down on the right, pin 6 is next down and 0v, then pin 8 which is transmitted data from the Pi, and pin 10 is received data to the Pi. The Nextion display came with a cable with a connector for the display. This has red for +ve, blue for data from the display, yellow for data to the display and black for 0V.

Continue reading...
M0RVB

Farewell Hamshack Hotline

All good things come to an end - Hamshack Hotline has closed down and the first of four lights on my SIP phone has gone out. Sad. I had been using the service for some time and I actually purchased a Cisco SIP phone from eBay specifically for it. In the end my 4-line SIP phone had all its lights lit as I also got numbers for Freestar, Hams over IP, and CNET which I replaced with Amateurwire later on. The phone seemed to lock up once the service was switched off - no idea if that was actually the cause as I disabled the line after a reboot. I also remembered to remove Hamshack Hotline from my Groundwire app. Of course, being the first one I signed up to it is on the top of the four line buttons on the phone. Now I need to edit the config to move things about.

Continue reading...
M0RVB

Another toy, another mode...

The latest addition to the shack is a Connect Systems Inc CS7000-M17 Plus hand held radio. I got this because of interest in the M17 mode - see https://m17foundation.org/ generally for information. The radio came from KB Cubed in the US (https://www.kbcubed.com/), not solely because the price had been reduced but also they were able to ship to the UK whereas other suppliers could not, or as far as I found anyway. It comes with a USB programming lead that attaches to the side once a cover is removed. However, as it came with the M17 mode already installed I have not yet needed this. The radio, being the Plus model will also do DMR which means I may no longer need the MD380 but I have yet to try this out. As there is no M17 activity around here I also needed a hotspot. I run the excellent pi-star package for DMR and POCSAG but there is a future issue - the main branch of the MMDVM software will no longer support M17 and once pi-star updates my hotspot would cease to function. As there is a WPSD branch with M17 retained I decided to set up a hotspot…

Continue reading...
M0RVB

Powering small LoRa devices

My latest reorganisation is to set up a Raspberry Pi to connect various LoRa devices providing power and a console to each. I have four such devices, three of which were powered from a 12V PSU with a USB adapter plugged into the 'cigar lighter' socket, adn one was powered from the ADS-B feed in the loft which in turn is powered by the Pi that does the ADS-B feed. That powers the rtl-sdr dongle plus an LNA, both colocated with the collinear in the loft. The new setup consists of a 7-way USB hub with switchable power to each USB connector. This hub is connected to the USB 3 port on a Pi 4B. Five ports are in use, one for the radiosonde receiver, one for the TinyGS receiver, one for the 868MHz Meshtastic node in the loft, and one for the 70cm Meshcom node also in the loft. The latter two are fed via 15m USB leads. The fifth connection is not an active device - it is my illuminated shack sign! This gives several advantages. First, each device can be power cycled without needing to fiddle with the USB connectors. Second, each can have a console on…

Continue reading...
M0RVB

SatNOGS

As if I didn't already have sufficient Raspberry Pi systems around the house I set up one for SatNOGS (https://satnogs.org/). I already have a little LoRa device for TinyGS so why not add somehting else satellite-y? I mean, there was a spare port on the Cross Country Wireless multicoupler (and indeed there are still two spare ports now). Configuring it all was relatively straightforward although you do need to read the information on the wiki first. I am using an rtl-sdr V3 dongle which was sitting doing nothing so itis nice to actually use the thing. There is plenty of information on how to set things up and my station is running in test mode while I check it all out. With my compromised setup I did wonder if I would pick anything useful up but it does seem to. The results can be found at https://network.satnogs.org/observations/?station=4293 At the moment everything is spread about. The Pi needs boxing up and a place found on the shelf, pulus the USB and RF leads need tidying but otherwise it all seems to work ok. I have added a Minikits LNA to give a bit more oomph. When configuring the system you use…

Continue reading...