This repository contains the software and the PCB designs of a radiosonde. This radiosonde is used as a platform to test and integrate payloads for the future CubeSat missions. Version 4.0 complies with the PC104 board standard for CubeSats. The balloon's software architecture uses a command pattern with a ZMQ data format.
The OBC of the radiosonde consists on a PC104 PCB board compatible with the design specification of the SUCHAI CubeSat. The shape of the board considers spaces to improve the cable management inside the radiosonde. The board has some socket pins to connect either a Raspberry Pi 3, 4 or Zero. There are also some sockets to connect sensors such as the BMP180 to measure temperature and pressure, the MPU-9250 to measure the attitude of the radiosonde and a XA1110 to obtain GPS and GLONASS data.
The PCB has some pin headers to select the power source from the stack. It also has 2 I2C pins to connect additional sensors or for debug. There is also a hole to pass the ribon cable of the camera to connect it to the Raspberry Pi.
- SBCs: Raspberry Pi 3, 4 and Zero
- GPS: XA1110
- IRIDIUM: RockBlock Mk2
- Sensors: BMP180, MPU-9250
- Raspbian Lite
The deployment system, also called release system, consists on using Nichrome wire to cut the thread that ties the balloon with the radiosonde's structure. This thread is normally pressing a hinge lever, which is used to detect the release status. The microcontroller can detect the current status by measuring the hinge level's voltage on one of its pins. When the microcontroller receives a command to cut the string, it polarize a mosfet transistor to pass current through the Nichrome wire.
This boards has two independent ports to release balloons. Each one with a LED for the deployment status.It also has a reset button accessible from outside the main structure.
The board is designed with the shape of a type A interstage panel like the one that CubeSats of 2U ore more can have. This saves space inside the structure and enables the compatibility with both radiosondes and CubeSats.
- Microcontroller: ATSAMD21E18 (TQFP32)
- Hinge lever: AV4524
- Mosfet: PMV16XNR
- TO DO
- Summary of set up
- Configuration
- Dependencies
- Database configuration
- How to run tests
- Deployment instructions
- TO DO
- Writing tests
- Code review
- Other guidelines