# Micro-Satellite Systems Design, Integration, and Flight
## 3 ChipSat RTOS and RF Development
### Testing RF on the TI Launchpads  
To transmit the sensor readings to be recorded, EM communication is needed because the ChipSats are not going to be retrieved. This fulfills requirement 1.0 (see Table 4), which was achieved using RF communication.  
The TI launchpad CC1310 was used as a testing device when developing the RF transmission code since it has the same microcontroller [34] as the ChipSats. The TI boards made the testing setup easier because the ChipSats had to be programmed through the launchpad. Also, it reduced the risk of harming the ChipSats if something went wrong at the beginning.  
The functionality of the TI launchpads and the speed, range, power, and filtering abilities of their transmissions could be checked and tested using SmartRF Studio version 2.18. Two TI launchpad CC1310s [35] were used with SmartRF Studio 7 for these tests. After installing and opening SmartRF Studio 7, the following screen will show up. See Figure 10.  
Figure 10 shows a list of connected devices in the bottom command window. It is recommended not to plug in both TI launchpads to the computer at first since they might  
\begin{table}
\begin{tabular}{c l l l} \hline \hline
**ID** & **Requirement** & **ID** & **Requirement** \\ \hline
2.1 & The system SHALL have 16-bit data & 6.0 & The system SHALL apply matched filtering \\ \hline
2.2 & The system SHALL collect magnetometer, accelerometer, and gyroscope data in 3D space & 7.0 & The signal SHALL be received by a ground station \\ \hline
3.0 & The system SHALL be frequency modulated & 7.1 & The signal SHALL be demodulated \\ \hline
4.0 & The system SHALL forward error correct (FEC) the data & \\ \hline \hline \end{tabular}
\end{table}
Table 4: _Cont._  
Figure 10: Connecting to TI launchpads on SmartRF Studio 7.  
be hard to tell apart. Instead, plugging the boards in one by one would let the user decide which board will be the transmitter and which one will be the receiver (marking them might help). By double-clicking on the device from the list of connected devices, the device control panel could be opened. The transmitter should use the packet TX mode. The transmitter should be set up as shown in the following screenshot. See Figure 11. The receiver should use the packet RX mode. It would be useful to have two separate windows open so both the RX and TX screens can be viewed at the same time. Make sure the sync words are the same for both the RX and the TX. Suitable settings for the RX receiver can be seen in the screenshot, see Figure 11 below.  
Both the transmitter and receiver have a start button at the top of the screen that needs to be pressed. The receiver will wait for the code word. So, it is necessary to start the receiver before the transmitter if one wants to obtain all the packets. This interface allows us to check the transmitting speeds, range, and power. As we expected, the launchpads sent signals well at nine-hundred and fifteen megahertz. The highest power was around fourteen decibels, compared to twenty-five milliwatts of transmitting power. The transmission distance was about 400 m.