The design of the OBC has been created to be easily understandable, to serve as a basis for future developments that can meet the expectations of the new conquerors of outer space. On this PCB you will find the elements commonly used in this type of system accessible for programming using the Arduino IDE.

The Main Module, or OBC (On Board Computer), consists of a state-of-the-art module of the ESP32-S2-WROOM type. Inside its radiation-proof metal insulation, it houses a powerful 32-bit LX7 microprocessor capable of operating at over 240MHz. 128 KB ROM. 320 KB SRAM. Wi-Fi 802.11 with bit rate above 150Mbps (2412 - 2484 MHz). And able to work with temperatures between -40ºC and +85ºC).

In addition, the OBC (On-Board Computer) module has a high-precision digital temperature sensor model MCP9808, with an accuracy of 1ºC between -40ºC and 125ºC. You will also find a voltage and current sensor model INA226 that will allow you to know at all times the consumption and quality of the energy that reaches your OBC from the solar panels/battery or USB. The OBC has a USB connector that will allow you to connect the device to your computer for programming, and a 20-pin connector with which you can connect it to other modules. Finally, the OBC module has a tricolour LED that you can program as an indicator of the status you need to display.

The whole assembly is housed in a 64x58mm PCB (Printed Circuit Board), respecting the recommendations set by the NewSpace community to be placed in a pocketQubes launcher (PocketQube Standard. The PocketQube Standard Issue 17th of June 2018).

The NessieSAT EPS includes control signals, inputs and outputs that allow it to control external devices and new PCBs. In this BUS called PQ20N you can find the following lines.

• UART RX (high speed serial data input connection)

• UART TX (high speed output data input connection)

• D5 Programmable digital input / output

• D7 Programmable Digital Input / Output (for use in EPS in Alert Power Detection)

• D6 Programmable digital input / output

• +3V3 Rail voltage from EPS

• AD3 Analogue input 12 bit resolution

• AD2 Analogue input 12 bit resolution

• AD1 Analogue input 12 bit resolution

• AD0 Analogue input 12 bit resolution

• DONE Interrupt input for indicating full battery charge

• IMU Interrupt input for IMU

• MISO High speed SPI BUS input

• CHG Input to indicate that the batteries are receiving power from the solar panels

• MOSI High speed SPI BUS output

• SCK SPI bus clock signal

• SDA I2C bus data signal

• SCL I2C bus clock signal

• GND Ground plane

• +5V Rail voltage