Hardware
The TTC board is composed by the following main components:
- MSP430F6659, as the beacon microcontroller.
- RF4463F30, as the radio module for the beacon and the telemetry link.
In the image below, a general hardware diagram can be seen, with the connection and protocols between the components:
The beacon microcontroller is the MSP430F6659IPZR. Its main characteristics can be found in the table below:
| Characteristic | Value |
|---|---|
| CPU | MSP430 |
| Frequency | Up to 20 MHz |
| Non-volatile memory | 512 kB |
| RAM | 66 kB |
| GPIO Pins | 74 |
| I2C | 3 |
| SPI | 6 |
| UART | 3 |
| DMA | 6 |
| ADC | ADC12-12ch |
| Comparators | 12 inputs |
| Timers - 16-bit | 4 |
| Multiplier | 32x32 |
| BSL | USB |
| Min Vcc | 1,8 |
| Max Vcc | 3,6 |
| Active Power | 370 uA/MHz |
| Standby Power (LPM3) | 2,6 uA |
| Wakeup Time | 3 us |
| Additional Features | USB LCD Real-Time Clock Watchdog DAC Temp Sensor Brown Out Reset IrDA |
| Operating Temperature Range | -40 to 85°C |
The NiceRF RF4463F30 is a transceiver module based on the Silicon Labs Si4463 radio. This module also contains a PA module to increase the output power up to 31 dBm.
In compliance with the TTC requirement 3, the RF4463F30 module operates with 5 V as input voltage in the TTC board, to achieve 30 dBm (1 W) in its output (The RF connector).
The RF4463F30 module uses the Si4463 radio module. The main characteristics of this IC can be found in the table below:
| Characteristic | Value |
|---|---|
| Frequency range | 119-1050 MHz |
| Receiver sensitivity | -126 dBm |
| Modulation | (G)FSK, 4(G)FSK, (G)MSK and OOK |
| Max. output power | +20 dBm |
| PA support | +27 to 30 dBm |
| Ultra low current powerdown modes | 30 nA shutdown, 50 nA standby |
| Data rate | 100 bps to 1 Mbps |
| Power supply | 1,8 to 3,6 V |
| TX and RX FIFOs | 64 bytes for each or 129 bytes shared |
The schematics of the TTC module can be found here.
The PCB (Printed Circuit Board) of the TTC module has basically the MSP430F6659 ic, the RF4463F30 module and all the external connectors.
Some characteristics of this PCB:
- The components and traces of the board are distributed over two layers (one in each side of the board).
- The RF modules are placed in a isolated ground plane (Connected to the main GND using a ferrite bead). This region can be seen in the figure below.
- The antenna output of the RF4463F30 modules are connected to their respective connector over a 50 Ohm coupled trace.
All the external connections of this board are described here.
The TTC PCB has two types of assembly: Develop and flight.
The develop type has the purpose to be used during the development stage and tests. In this version, the connectors 3 and 5 are not soldered (Using this page as reference).
The flight version were designed to be used during the satellite operation. In this version, the connectors 1, 2, 4 and 6, and the reset button, are not soldered.
The detailed power consumption of the TTC module is available in the tables below.
Static power consumption:
Dynamic power consumption:
