Aims
The Senior Scouts have the following aims that they wish to accomplish with this project:
- Construct a holder for the payload
- Construct a parachute for landing
- Take pictures of Near Space
- Take temperature measurements
- Communicate GPS position to the ground during flight
- Record flight
The first part the Scouts need to consider is the payload and what electronics they wish to use inside.
The Electronics
When we are thinking of ways to tackle this challenge we first need to have a clear idea of what the electronics in the payload needs to accomplish:
- Transmit to base station the GPS co-ordinates of payload during flight
- Take temperature measurements both internally and externally of the payload
- Trigger a set of cameras to take pictures during the flight
Of course, this is a very generalised picture of what needs to accomplished, it is always best to stay away from the technical details at the early stage of planning – failure to do so will complicate the design specification and we will start chasing our tails, so to speak.
We believe there are two main options open to us, both have a certain degree of overlap so if one doesn’t work out it would not be too difficult to change late in the day. The two choices are: use a micro-controller such as PICAXE to control the onboard systems and design all hardware and software, or go for the Raspberry Pi and write our own software with a small amount of adapting for hardware.
Using Raspberry Pi
The Pi allows more possibilities for processing and with their new camera board being released in April it would allow the cameras to be more compact and ‘plug-and-play’ style connection. It also has onboard memory which could be utilized as a buffer to write all the in-flight data into a flat file.
The block diagram for the Pi would be as follows:
The first point to consider is that, by making our own board and design the package is completely bespoke, meaning that it should be as efficient as could be. By doing this, however, we sacrifice time. To design, test, build and test a lot more, a completely bespoke system would take a huge amount of time.
Therefore, we shall continue with the Pi.