All Development related posts in here

SPOT updates logging to the positlogger website
Dec
24
2014

SPOT tracking to APRS.FI

Our SPOT is used as a secondary tracker and we have been trying for a while to get its tracking updates to aprs.fi. We use aprs.fi as the main tracking map and now we have finally got the SPOT follow-me 10minute updates appearing on aprs.fi. To do this we use an intermediate site called positlogger.net […]

2m Tape Measure Yagi
Oct
17
2014

2m Tape Measure Yagi

This design has been around for a long time and we thought it woudl be good to have a 2m Yagi antenna to use to find the tracker if all our other tracking methods fail This design was by Joe Leggio WB2HOL who has a great write up here on how to build one so […]

Laptop running iGate Software connected to THD72A with antenna on the roof
Oct
16
2014

iGate mounted in 4WD

Our iGate is now mounted in the 4WD. – The laptop has a custom wooden mount which sits on the centre console of the defender – The Kenwood TH-D72A sits in the drinks holder. An antenna mounted on the roof racks provides great reception – A custom mount for the Inverter, Laptop power supply and […]

Habduino packaged with on/off switch and dipole Antenna
Oct
15
2014

Habduino Tracker packaged & Ready to fly

Our Habduino tacker has been through a lot of testing including tied to the front of the 4WD and driven at 100km/hr. It packaged in a foam container with the GPS antenna and radio antenna attached. This configuration includes string loops for connection to the inline balloon string

Sep
24
2014

APRS Mobile iGate

When balloons we are tracking are at low attitude on launch and descent the closest iGates can be 100km or more away and we dont get updated from the onboard trackers. To help get accurate positions we have installed APRS iGate software on our laptop and connected to our Kenwood TH-D72A. APRSISCE is developed by […]

IMG_6498
Sep
12
2014

Redundant Pressure Shield – cutdown

We have finished the pressure shield in its redundant configuration. It can work in a single standalone or dual redundant mode. Based on Arduino Elevens with custom shield. Uses a timer cutdown as well as air pressure measurements to shutdown the cutdown and “safe” the nichrome cutters.

Mar
19
2014

Arduino based Tracker – Habduino

We have taken delivery of an Arduino based APRS and RTTY tracker called Habduino. The Habduino uses a 10mW UHF transmitter on 434.650Mhz and a 300mW VHF transmitter on 145.175Mhz for APRS. The Habduino was developed by Anthony Stirk.   We built a 70cm UHF dipole 1/2 wave antenna  and used our existing 2m VHF […]

Mar
12
2014

Balloon Flight Simulator on Arduino

We are still in the process of building a redundant cutdown device to meet CASA medium balloon regulations. The redundant cutdown needs to be able to respond to condition on its own without intervention from the ground, so we have developed a balloon flight simulator that runs on the Arduino along with the cutdown code. […]

Feb
23
2014

Pressure Shield Testing

To comply with CASA regulations for medium balloons we need to fly redundant cutdown systems. Our design uses Ardunino’s (Freetronics Eleven) devices as the heart of the redundant cutdown. We have opted to use a pressure sensor to let the Arduino know if its going up, floating at the same altitude or falling. Our initial […]

Apr
28
2013

Cold Soak Testing Cutdown

We now have the cutdown working at +20C, the test below shows  it can cut through the load string. We have simulated the payload with a 2kg weight. At +20C the cutdown glows red to orange and easily cuts through the load string. The arduino is programmed to provide power to the nichrome for 5 seconds then […]

Feb
06
2013

Payload Cutdown and Balloon Envelope Termination Design

As we are going to fly a medium sized balloon (as defined by CASA) we need to include 2 independent balloon envelope (read balloon popping) devices and 2 independent payload cutdown devices. We completed a design in early February . We decided on using timers on all devices and would perform cutdowns in this order […]

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