Monday, November 27, 2023

DigiPi -2-

Mosquitto / MQTT

One of my first experiments starting with DigiPi on my Raspberry Pi 4 was to install MQTT ( Mosquitto )  

sudo remount

sudo apt-get install mosquitto
sudo apr-get install mosquitto-clients

sudo systemctl enable mosquitto
sudo systemctl start mosquitto
sudo systemctl status mosquitto

The commands above gave no special problems. To using mosquitto over the network additional setup is needed. This protection only demonstrates attention to safety of DigiPi. 

mosquitto -v 

1700517586: mosquitto version 2.0.11 starting
1700517586: Using default config.
1700517586: Starting in local only mode. Connections will only be possible from clients running on this machine.
1700517586: Create a configuration file which defines a listener to allow remote access.
1700517586: For more details see
1700517586: Opening ipv4 listen socket on port 1883.
1700517586: Error: Address already in use
1700517586: Opening ipv6 listen socket on port 1883.
1700517586: Error: Address already in use

Local test

As (local) test i typed in a terminal screen (i used the browser terminal) to subscibe to mytest 

mosquitto_sub -d -t mytest

In another screen (for this i did log in using putty) i published "demo" to mytest

mosquitto_pub -d -t mytest -m "demo"

And got the expected response !
Perhaps i will later on use MQTT in combination with DireWolf
To use mosquitto over the network additional setup is needed. This protection only demonstrates attention to safety of DigiPi.

Saturday, November 25, 2023

DigiPi -1-


As i have a HAM licence I was looking for HAM software for my Raspberry Pi 4.
What often pops up is DireWolf, not the animal or the game!
DireWolf is  “Decoded Information from Radio Emissions for Windows Or Linux Fans”)  and was developed by John Lagner, WB2OSZ. As the name implies it can run on PC's and even a Raspberry Pi.
Also i found DigiPi ( ), the KM6LYW Radio DigiPi Project
DigiPi is a hot-spot for all amateur radio data modes, including APRS, ax.25, winlink email, ft8, js8cal, slowscanTV, PSK31, packet and even CW.  The implementation is an elegant, inexpensive, low-power, open-source Raspberry-Pi--based amateur radio data transceiver, managed exclusively by web browsers or smart-phone apps, with no bulky keyboards, monitors or complicated wiring.  At the website you can download an image for the raspberry pi with the options mentioned above already installed (including DireWolf and a web-interface.
DigiPiAt this moment (november 2023) the DigiPi image is behind a paywall, and the password is available to patrons on the KM6LYW Patreon Page. Anything gets you access to the DigiPi image, even a dollar. According to KM6LYW the point is not to keep the software locked up, but to ultimately throttle the  questions and support load.  Plus it gives priority access to design  decisions, code contributions and early releases. DigiPi is community driven  and open source.
I made a small contribution and could download the image and put it on an sd card for my Raspberry using BalenaEtcher. (Also other sdcard writing tools can be used.)
I did not yet connect a ham radio and wanted to experiment with the software on my Raspberry and am interested in DireWolf and a sdcard with DigiPi seemed a nice way to start.
Also (as i am just starting up my HAM activities) i do not have one of the many transceivers on a list, that can be connected directly via USB to the DigiPi, however it also possible to interface over audio.  For experimenting i recommend to plug in a USB audio device in the USB (perhaps in the beginning with nothing connected) as the software does sense if no interface is available and in that case it will not go to some options.

The installation

There is sufficient info available to make the system work, however i had some special wishes and also wanted to experiment.
I want the network connection running over the wired ether-net interface, not over Wifi. Also i like to run some other software (The Mosquitto MQTT server) and perhaps later interface this with DireWolf.
Therefore i connected an ether net cable to my LAN and booted the system.
The DHCP server of my home-network did give the IP to the ether-net connection of the system. (The IP address of the Wifi is managed by the DigiPi).
What i did and not every time will mention is that installed parts needs to be activated (by (re-)starting the service or a reboot of the Pi). So see this as a general guide not an exact list of commands that always will work for you!

Timeserver / nameserver problem

I noticed the date and time on my pi where not correct.
Over the wired network i could reach the system  (using hostname  "DigiPi" or the IP address)
I did try to configure ntp, however i did not find the configuration files.
I made the decision to install ntp using "sudo apt-get install ntp"
However i did not succeed as the nameserver was missing and sites on the internet could not be reached by name.
At the bottom of dnsmasq.conf is 

#craiger hotspot stuff

#AutoHotspot Config
#stop DNSmasq from using resolv.conf
#Interface to use

I changed changed no-resolv to #no-resolve and after this domainnames on internet could be resolved.

Now i could install ntp using "sudo apt-get install ntp" however i did not investigate the  system sufficient !! :
During ntp install i noticed removal of "chrony" and that is (a better) alternative for ntp.
I expect the time was not updated as the timeserver on internet could not be reached by chrony. So better not install ntp !
At this point i could go back and create a fresh sdcard and i am sure i will need to do that some time however
 "sudo apt-get install chrony"
gave me back chrony and i noticed the date and time where now correct.

Some links:

to be continued

Wednesday, August 30, 2023

Mailbag July 2023

A new mailbag post with some backlog mail.
(I planned to post this July mailbag begin Augustus, however it is already end August and some new interesting products have arrived for my next mailbag blogpost.

USB External soundcard.

As i want to experiment with audio signals i did buy an external to protect the sound chips of my computer

USB External soundcard.

Another sound card.
I was happy to have ordered 2 different cheap soundcards as my first experiments where more successful with this card that with the other one.

USB receiver

QRP Tranceiver
More connectors

Nice storage bag for cables
Cheap bluetooth USB led strip

A review of this product was already published on my blog

Air T split with valves

I want to make a ventilation system in my new shed using the Inline Blower.
This is a T splitter with 2 valves for the ventilation system.
This corner pieces also to use for ventilation system
Some more valves for the ventilation system
Cable binders (black)
Cable binders colored
Heatshrink, always good to use for electronic projects, you can never have enough
More connectors
Connectors with a small cable
Portable antenna
I hope to make a dedicated blogpost about this antenna 
Dupont / crocodile clip cabes

Mosquito killer lamp

And even more connectors

Thursday, August 10, 2023

Bluetooth USB led strip

This is a review of  a cheap Bluetooth USB led strip.

AliExpress advertisement campaign tells you you can buy 3 (or more) items from a selected list for US $1.99 or ~1.84 Euro each. Often interesting products can be found and i already did buy some of them. I stumbled upon a one meter USB Bluetooth RGB ledstrip. For this price it is an an interesting product and perhaps i can use it later in my new shed so i decided to put it on the pick list and ordered it.

Very soon it arrived together with other below 2 euro products in a packed in a separate plastic envelope. Here below a short review of the cheap Bluetooth USB led strip.

Bag with the led ledstrip

When powering the leds on a changing a red - green - blue light sequence started. According to the description it should be possible to control this led strip via Bluetooth. However there was no clear description how to do this.

On the cable is a small QR code. I tried scanning it however i was not very successful. I hoped the QR code would link to some vendor website or an app on the Google playstore for controlling the led strip.  Instead the QR  code linked to some (unrelated ?) TikTok video (i don't have TikTok installed). Perhaps when TikTok is installed a video about the device will be shown, however on my phone some unrelated TikTok movie started and i was asked to install TikTok. However i did not want to re-install TikTok just for this device after i de-installed it for security reasons some time ago,

QR code on led strip

On the vendor's page at Aliexpress was also no clue so i scanned for Bluetooth devices. My Android phone i did find a BlueTooth device named "ELK-BLEDOB". When connecting to it my phone told me i needed a special app for it.

After some quick searches on the internet this device name seemed for LedStrips and i decided to install some 'generic' app for led strips. In the Google App store i found an app called "duoCo Strip" and installed it. After installing i found a new app named "Lotus Lantern" and after a virus scan i started it.

 I did struggle a little to connect the bluetooth device in the app, however finally it worked and i managed to change the colors of the led strip, tested some of the sequences and also tested the color changing using music or sounds received by the smartphone microphone. For details see the help pages of the app. (you can find screenshots of this in this blog posting),

After disconnecting and reconnecting the USB led strip started using the last selected sequence. I did not test the led strip for a long time , sometimes i needed to reconnect it and also in the beginning the led's reacted relative slow to the app, however that improved during the use.

 In summary for this price (less than 2 Euro's) a nice USB powered 1 meter Led strip that can be controlled via Bluetooth.

Tuesday, July 11, 2023

Mini portable uninterruptible power supply (manual)

Some additional picture of the UPS shown in my last post 
My Mini UPS:

The manual:

Friday, July 7, 2023

Mini portable uninterruptible power supply

Recently i received this mini portable uninterruptible power supply (UPS) that i ordered after seeing a YouTube video of this interesting device. On AliExpress it is advertised as "Mini Portable UPS Router 5V 9V 12V Uninterruptible Power Supply for WiFi, Router Large Capacity Backup Power Adapter Ups Backup"

From the title you and seeing two Ethernet connectors you could think it contains a router or Wifi, however Ethernet connectors ar only available as this small power supply also can provide power over Ethernet (PoE). With a small switch you can select between 15V or 24V PoE.
Is also has a 5V USB outlet and 3 sockets providing  5, 9 and 12 Volt. It has a lithium battery and a circuit to act as UPS when main power stops. On top is an on and of switch and an indicator showing charging level. A European and USA type cable are provided for the main power voltage. Also included are a 'normal'cable and a 'split' cable for the 5,9 and 12 volt connectors.
It is a nice device that maintains power in the event of a power failure and provides some often used voltages. The 5V USB connector is also useful to have. It is not possible to draw all the advertised power at the same time and the power output is somewhat limited. For example it is not possible to power my FritzBox router using this device. If it could power my FritzBox i probably would have ordered immediate a second one to keep my network on in case of a power failure.

Product specification:

Battery capacity: 10400MA
Input: 85-265Vac
Frequency: 50-60Hz
Output: USB 5V/2A
DC 5V/1A
DC 9V/1A
DC 12V/1A
POE 15V/0.6A
POE 24V/0.6A
Output power (max):18W
Operating temperature:-10℃~40℃
Product size about:16CM*10CM*3CM
Weight 440 gram.

Below photos of the box and the unboxing: