Assembled Radiosonde
Exploded View
The Analog Devices ADF7012 FSK transmitter gets its reference clock from the 8 MHz MCO output of the MCU. The MCU handles the control interface of the radio via bit-banging over standard port pins. TX data is sent asynchronously to the ADF7012 TXDATA pin. The MCU generates transmit data with the help of TIMER21 and its TIM21_CH1 output. A PA (unknown type) boosts the output signal.
Modulation is 2FSK with 5.5 kHz deviation. Data bits are sent Biphase-M encoded in short bursts with 4800 bit/s (9600 smbols/s).
Main PCB Scan
Sensor Boom Scan
Still some stuff missing here...
| Designator | Function | Manufacturer | Part Number |
|---|---|---|---|
| U1 | MCU | STM | STM32L051R6T6 |
| U2 | GPS Receiver | Sierra | XM1110 |
| U3 | Pressure Sensor (optional) | STM | LPS22HB |
| U101 | Switching Regulator | Microchip | MCP1642B-ADJI/MS |
| U102-104 | LDO | TI | LP5907MFX-3.3 |
| U201 | Transmitter | Analog Devices | ADF7012 |
| U301 | RC Oscillator | X | TL555I |
