Funcube Dongle » History » Version 4
laforge, 02/19/2016 10:52 PM
1 | 4 | laforge | [[PageOutline]] |
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2 | = Funcube Dongle= |
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4 | 2 | laforge | The Funcube Dongle Pro (FCDP) is a small USB-key-sized low-bandwidth SDR. |
5 | 1 | laforge | |
6 | 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. |
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8 | However, for capturing a single TETRA channel, those 80kHz is actually more than sufficient. |
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10 | 1 | laforge | == Hardware == |
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12 | === Major components === |
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13 | The FCDP hardware seems to be using the following components: |
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14 | * Microchip PIC24FJ32GB002 |
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15 | * 16-bit low power microcontroller with Full-Speed USB, 32 KB Flash memory, 8 KB RAM, and advanced peripherals, 28-pin package |
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16 | * homepage: http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en536120 |
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17 | * datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/39940d.pdf |
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18 | * TI TLV320AIC3104 Low-Power Stereo CODEC with 6 Inputs, 6 Outputs, HP Amp and Enhanced Digital Effects |
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19 | * homepage: http://focus.ti.com/docs/prod/folders/print/tlv320aic3104.html |
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20 | * datasheet: http://focus.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=tlv320aic3104&fileType=pdf |
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21 | * Elonics E4000 Zero-IF Low Power CMOS Multiband Tuner (64 to 1700 MHz) |
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22 | * homepage: http://www.elonics.com/products/rf_tuners.do?id=1 |
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23 | * product brief: http://www.elonics.com/assets/PB_E4000_10_2009.pdf |
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25 | === Architecture === |
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26 | The hardware architecture therefore is quite simple: |
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28 | 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. |
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30 | 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. |
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31 | 2 | laforge | |
32 | 3 | laforge | {{{ |
33 | #!graphviz |
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34 | digraph G { |
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35 | graph [ rankdir = LR ] |
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36 | |||
37 | Antenna -> "Elonics E4000" |
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38 | "Elonics E4000" -> "TI AIC3104" [ label = "I/Q baseband" ] |
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39 | "TI AIC3104" -> "PIC24" [ label = "PCM" ] |
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40 | "PIC24" -> "Host PC" [ label = "USB" ] |
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41 | } |
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42 | }}} |
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43 | |||
44 | 4 | laforge | === Image === |
45 | [[Image(fcdp_pcb.jpg)]] |
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46 | 2 | laforge | == Software == |
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48 | The OsmocomTETRA repository contains a demodulator script called '''fcdp-tetra_demod.py''' that can be used with the FCDP. |
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49 | You have to use the 'qthid' application provided with the FCDP in order to tune to the respective tetra carrier frequency. |