Lock Down Project March 2020 - High Altitude Balloon

I started this project in March 2020 thinking it would only take me a couple of months. It ended up taking me the guts of 6 months. 

Firstly I knew nothing about high altitude ballooning. 

Where to start:

https://www.daveakerman.com/

https://ukhas.org.uk/

http://habhub.org/

Code - https://github.com/sonicepk/FlexTrack
Parts/Components - Aliexpress

Arduino Mega/Uno
NTX2B radio
uBlox MAX-8Q GPS receiver
ESP32-CAM
DashCam Camera SJCAM
Siemens GPS modem
Batteries – Energizer Lithium Max
Polystyrene sheet cut to shape
Hot glue gun
Name of payload/radio call sign HarryS1 after Harry Styles!
String, 45Kg breaking strain
Gaffa tape
Red paint
Special silver marker/pen

Make your own antenna. 

https://ukhas.org.uk/guides:payload_antenna

 

Frequency 434Mhz
Low power < 10mW
Transmitter used NTX2B – cheap/available/reliable/proven to work
Transmission protocol RTTY - Baud rate of 50bit/s
Frequency Shift Key. ON/OFF keying. 

Network of radio receivers around the world. One in Northern Ireland, none in the Republic.
Decent radio receivers are expensive.
Thankfully, relatively cheap USB software defined radios (SDR) are now available that can be used. But I had no experience. Advice was not to use, and only suitable for testing at home.
Purchased a cheap(30 Euro) SDR USB receiver from NOOELC. Worked up to 12Km until we lost signal due to loss of line of sight rather than radio signal. Very impressed with NOOELEC.
Gets hot – added small cooling fins! 

 

 

USB SDR modem
Windows 10.
Opensource CubicSDR software for receiving and demodulating the signal
VB-Jack, software audio input/output jack. Feed output from Cubic SDR to DL-Fldigi
DL-Fldigi – modified version of Fldigi used to decode RTTY signal and upload CRC validated strings to the HABHUB tracker website for live tracking

 

 

Results

 

 

 

 

 

https://www.youtube.com/watch?v=1SP6DLWCTBo&t=1242s