In addition to the sensors, there are several other pre-designed modules that you will be interacting with. These modules are specified to make things consistent between all of the teams and help ensure that we can communicate with your femtosat.
Purpose: communicate with the ground from the femtosat
Note: The above library is based on the library mentioned in the hookup guide but has been modified for use in the competition. Please use that version on your femtosats.
Radio – What to do
Correctly add the radio to your schematic, and connect the antenna, power, grounds, DIO, and SPI lines. When building the board design, make sure that the antenna is close to its pin. After testing and building your design, contact the radio mentor to set up a time to test the radio.
The radio modules are 3.3V and the Arduinos from the shop are 5V. If you connect them directly, you will kill your radio module! Put 1k Ohm resistors in series with the MISO, MOSI, SCK and SS wires to protect your radio. This is only necessary with the dev boards, you don’t need to do this on your femtosat.
What you don’t need to do
You won’t need your own equipment for the radio testing. The radio mentor will have access to the club’s equipment. If your radio isn’t working correctly, don’t worry! There are many potential issues that can cause this. The radio mentor will have a good knowledge for trouble shooting and will be able to help you.
On launch day the radio on your femtosat will be communicating with a ground station - radio equipment setup specifically to communicate with the femtosatellites. There are five main components for the ground station.
Computer -> SDR (Software Defined Radio) -> Filter -> LNA (Low Noise Amplifier) -> Antenna
The antenna receives the signal, the LNA amplifies it (makes it stronger), the filter takes off the extra edges, the SDR decodes, and the Computer displays. It is simple to set up, but it must be done correctly for it to work. We will take care
Purpose: provide a backup to the radio
Arduino Library Download: coming
The primary means of communicating with spacecraft is through the use of radios. However, because we will be recovering the femtosats we have the opportunity to have a backup system. The memory module is a module that we designed in the Spacecraft Club to help with your femtosats. Your femtosats will be able to communicate with the device and send all of the data to the module. Then the memory module will store everything you give it into a file. Once we recover your femtosat we will download the saved information and provide the file to you. Implementing the module should be straightforward. Information on interfacing with the memory module is included in the starting schematic. There is also a library provided to communicate with the memory module.