Picture from the edge of space – Design
(This post is a work in progress for the moment., It will be updated as my design evolves)
Balloon
Materials
- 800gm Weather Balloon
- N10 Helium Canister
Flight
With some help from CURF‘s predictor looks like the balloon will travel for around
- 2 hours 30mins
- Cover about 300km (Going about 75 mph!)
This of course, is based the weather on the day, I should run the predictor a few times,
Payload
Boxing
- EVA foam, its lightweight, and I can work with it to shape it into what I need.
- Paracord for the ropping
Controller Parts
- Rasperry Pi B+
- BMP180 Weather Module, for Pressure, Alt, Temp etc…
- BO23 “Slice of Radio” as our Radio Transceiver
- MTK3339 as our GPS Receiver
Power
This is still an on going question, though it looks like lithium AA battries, connected up to provide 5V.
Wiring plan
GPIO Pins
Header Pin | PI Usage | Allocated for |
1 | 3.3 | BMP180 – VIN |
2 | 5v | |
3 | I2C/SDA1 | BMP180 -SDA |
4 | 5v | |
5 | I2c/SCL1 | BMP180 -SCL |
8 | TXD0 | SOR -TX |
9 | Gnd | BMP180 -GND |
10 | Rxd0 | SOR -RX |
14 | Gnd | SOR -GND |
15 | GEN | SOR – DTR |
17 | 3.3 | SOR -3Vo |
USB
I cant wire the GPS module in as I would like as it used the Tx/Rx pins just as the radio does. SO I am going to wire it to a USB interface and connect to it as TTL device. The model I am using just outputs string, that I can read in like a console.
Tracking
I know I am going to use Habitat, I still need to get to grips with it, so far as I can see it works like this:
GPS -> Pi -> Radio -> Your laptop in the car (or a helpful station you pass) -> To the internet -> Then Habitat updates its space tracker.
Final Budget and
Item | Source | Price |
Balloon | ||
800g Balloon | Link | 45 |
Helium | 70 | |
Tracker | ||
Raspberry Pi | Link | 36 |
Radio RT | Link | 10 |
GPS Module | Link | 34 |
Barometric module | Link | 8 |
Camera | Link | 17 |
UART USB Converter | Link | 6 |
Breakout 40pin + cable | Link | 5 |
BreadBoard | Link | 8 | BatteryPack | Link | 15 |
Total | 254 |