Satellite Control Board
The project basically involves the control card design inside a satellite.
The Satellite Control Card is designed to fulfill the most basic and critical functions in order to carry out the mission process of the satellite to which it is connected.
These critical tasks are:
- Being able to read and process data from sensors without any problems.
- To be able to send data from sensors to the Ground Support Station.
- Calculating real-time location data and sending it to the Ground Support Station.
STM32F101C8T6 microprocessor was used as the processor. It processes the data received from sensors and peripheral units and provides relevant commands.
The circuit receives its power energy from 2x3.7V Li-Po batteries. This energy must be distributed to the elements in the circuit in a controlled manner. For this purpose, there are 5V and 3.3V reducing linear regulators on the circuit. By using these regulators, voltage fluctuations that may occur in the circuit are eliminated and pure DC energy is transmitted to the units on the circuit.
BMP280, one of the sensors on this board; Temperature and barometric pressure values can be measured directly. Data flow was provided using the SPI communication protocol with the BMP280 sensor processor. The data obtained from this sensor is used to obtain the altitude data of the satellite. Thus, GPS location improvement is also achieved.
The electronic card contains gyroscope and accelerometer units that can measure in 3-axes in the MPU6050 6 Axis Acceleration and Gyro Sensor. Data flow was provided using the I2C communication protocol with the MPU6050 sensor processor. Using these units, yaw, pitch and roll angle as well as the rocket's speed are calculated.
The satellite is intended to provide position information through the GPS Module throughout its mission in the air. It was preferred to make a connection via terminal instead of a direct connection on the board. Terminal connections are designed in accordance with the UART communication protocol.
Telemetry data is sent to the Ground Support Station via the XBEE S2C Pro module. Since the data flow between the XBEE S2C Pro Module and the processor supports UART communication, the connections on the terminal block are designed in accordance with the UART communication protocol.
In addition, the system is planned to provide the connections required for the operation of both the camera and a servo motor connected to the camera via terminal blocks.
The circuit includes an oscillator (clock) circuit for use by the processor, a Reset button for manual "Reset" operation with a button, a Programmer, a Micro SD Card Socket circuit and a Buzzer circuit.
Thus, many parameter data are obtained during the satellite's mission process.
Since the sensors were preferred as IC instead of modules in the circuit design, care was taken to use decoupling capacitors, taking IC health into consideration.
All electronic components used in the project are as follows:
STM32F101C8T6
8 Mhz 12.5 pF Oscillator
2 x 3.7V Li-Po Batteries
LD1086DT50TR (5V Regulator)
LD39150DT33-R (3.3V Regulator)
Micro SD Socket
BMP280
MPU6050
GY-NEO6MV2 (GPS Module)
XBEE S2C PRO
5V Buzzer
