Funcube Dongle » History » Version 2
laforge, 02/19/2016 10:52 PM
1 | 2 | laforge | The Funcube Dongle Pro (FCDP) is a small USB-key-sized low-bandwidth SDR. |
---|---|---|---|
2 | 1 | laforge | |
3 | 2 | laforge | It uses an audio codec as ADC (like many amateur radio projects) and thus can only be used for narrow-band signals up to 80kHz. |
4 | |||
5 | However, for capturing a single TETRA channel, those 80kHz is actually more than sufficient. |
||
6 | |||
7 | 1 | laforge | == Hardware == |
8 | |||
9 | === Major components === |
||
10 | The FCDP hardware seems to be using the following components: |
||
11 | * Microchip PIC24FJ32GB002 |
||
12 | * 16-bit low power microcontroller with Full-Speed USB, 32 KB Flash memory, 8 KB RAM, and advanced peripherals, 28-pin package |
||
13 | * homepage: http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en536120 |
||
14 | * datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/39940d.pdf |
||
15 | * TI TLV320AIC3104 Low-Power Stereo CODEC with 6 Inputs, 6 Outputs, HP Amp and Enhanced Digital Effects |
||
16 | * homepage: http://focus.ti.com/docs/prod/folders/print/tlv320aic3104.html |
||
17 | * datasheet: http://focus.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=tlv320aic3104&fileType=pdf |
||
18 | * Elonics E4000 Zero-IF Low Power CMOS Multiband Tuner (64 to 1700 MHz) |
||
19 | * homepage: http://www.elonics.com/products/rf_tuners.do?id=1 |
||
20 | * product brief: http://www.elonics.com/assets/PB_E4000_10_2009.pdf |
||
21 | |||
22 | === Architecture === |
||
23 | The hardware architecture therefore is quite simple: |
||
24 | |||
25 | The PIC24F implements the USB protocol/interfaces for HID (tuning) and audio towards the PC. It also drives the TI codec and the Elonics silicon tuner via an I2C interface. |
||
26 | |||
27 | Analog RF data enters the Elonics silicon tuner, where it undergoes zero-if down-conversion to complex I/Q baseband, which enters the TI audio codec where it is digitized using left/right channels for i/q. The resulting digital audio stream is passed to the PIC24F, which forwards it via USB to the host PC. |
||
28 | 2 | laforge | |
29 | == Software == |
||
30 | |||
31 | The OsmocomTETRA repository contains a demodulator script called '''fcdp-tetra_demod.py''' that can be used with the FCDP. |
||
32 | You have to use the 'qthid' application provided with the FCDP in order to tune to the respective tetra carrier frequency. |