Projects

Below i share some information about my hamradio and electronics projects. Some of these projects are "work in progress" others have lost my focus or "completed" :)

APRS Modem

APRS project built on Arduino NANO and LibAPRS from Markqvist. This is an Arduino IDE library that makes it easy to send and receive APRS packets with a MicroModem-compatible modem. Also implemented a cheap serial TTL GPS for position reporting. The board have the possibility to connect other sensors like temperature etc. I have some spare PCB's for this APRS Modem (see picture below) laying around if anyone is interested please send me an email…

Above is picture shows the APRS modem used in a remote station setup together with a Boafeng UV82 radio and a simple timer. The timer was used to save power in idle mode and It was scheduled to trigger transmission 4 times a day. The "payload" data was outside temperature at the remote site.

Above is a early setup of APRS modem together with Baofeng radio

SWR meter

Built this modified Bruene SWR meter bridge, this meter has served me well connected to the Flexradio 1500 on the HF bands

Satellite tracker

I have for some time wanted to build a antenna tracker to use on the amateur radio satellites in low earth orbit. The SARCNET design has good description and they provide the software for the Arduinio Pro Micro, so no need to reinvent that. WIth YagiCAD software i designed a portable light weight dual 2 meter/70 cm Yagi Uda antenna giving around 9 dB gain. The rotator is build on a tripod with plumbing pipes a satellite tv rotator for elevation motion and a 1 rpm 12V motor for azimuth. One of the advantages with this design is that it utilises a motion sensor and electronic compass as feedback on pointing direction in both elevation and azimuth (X-Y )plane. for amature iuse this setup gives enoug accuracy. As controller i used a Rasparry Pi with GPREDICT installed. The setup worked fine, and i was able to recive and tranmsitt without any big issues. This project still needs some improvemnts to the cabling and tweeking of the motor controlls. Also some interference on 2m when running big jumps on the elevation.

Thanks to the people at SARCNET for providing SW and circuit diagrams

L-Match

USed this L-Match with a longwire and counterpoise on the Flexradio 0.5W and WSPR, happy with the conntact in eastern parts of Australia.t

Boombox

Wooden Boombox with car stereo and speakers. Inside a VRLA lead acid battery to power it all... simple but solid

NMEA Simulator

NMEA simulator i built some years ago after missing a tool to assist working on marine sensors and equipment. It can receive NMEA strings from marine sensors (wind,position,heading etc) to verify that the string is sent at the correct baudrate and contains the correct data. Before this i used a laptop with hyperterminal... carry a laptop with me. It also have the possibility to transmitt fixed NMEA sentences for wind, heading and position to assist during troubleshooting...

Screamalert

Screamalert is a desperate attempt to lower the noise level at the dinner table. It is built using the arduinio nanot the acceptable soundlevel with the potmeter. If the sound level in the room is going above this set level the box will make a sound.

Visual Clock

Also a project to aid with the kids. We were tired of having the kids going out of theire room and waking th whole house very early in the mornings, or in the middle of the night.... thinking it was morning. Modified a wall clock with a timer and a Red LED to visual show when it was night(Red LED on) and when it is morning (Red LED off)