Funcube Dongle » History » Version 9
laforge, 02/21/2016 08:54 AM
1 | 7 | laforge | {{>toc}} |
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2 | 1 | laforge | |
3 | 7 | laforge | h1. Funcube Dongle |
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6 | 2 | laforge | The Funcube Dongle Pro (FCDP) is a small USB-key-sized low-bandwidth SDR. |
7 | 1 | laforge | |
8 | 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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10 | 1 | laforge | However, for capturing a single TETRA channel, those 80kHz is actually more than sufficient. |
11 | 6 | laforge | |
12 | It is generally available for purchase from http://www.funcubedongle.com/ - however, it is out of stock almost all the time |
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13 | 1 | laforge | and you will have to click the order button at exactly the right time in order to get one. Apparently it is impossible for |
14 | the manufacturer to keep up with the demand. |
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17 | 7 | laforge | h2. Hardware |
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21 | h3. Major components |
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23 | 1 | laforge | The FCDP hardware seems to be using the following components: |
24 | 7 | laforge | * Microchip PIC24FJ32GB002 |
25 | ** 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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26 | ** homepage: http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en536120 |
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27 | ** datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/39940d.pdf |
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28 | * TI TLV320AIC3104 Low-Power Stereo CODEC with 6 Inputs, 6 Outputs, HP Amp and Enhanced Digital Effects |
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29 | ** homepage: http://focus.ti.com/docs/prod/folders/print/tlv320aic3104.html |
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30 | ** datasheet: http://focus.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=tlv320aic3104&fileType=pdf |
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31 | * Elonics E4000 Zero-IF Low Power CMOS Multiband Tuner (64 to 1700 MHz) |
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32 | ** homepage: http://www.elonics.com/products/rf_tuners.do?id=1 |
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33 | ** product brief: http://www.elonics.com/assets/PB_E4000_10_2009.pdf |
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36 | h3. Architecture |
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38 | 1 | laforge | The hardware architecture therefore is quite simple: |
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40 | 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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42 | 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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44 | 8 | laforge | {{graphviz_link() |
45 | 3 | laforge | digraph G { |
46 | graph [ rankdir = LR ] |
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48 | Antenna -> "Elonics E4000" |
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49 | "Elonics E4000" -> "TI AIC3104" [ label = "I/Q baseband" ] |
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50 | "TI AIC3104" -> "PIC24" [ label = "PCM" ] |
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51 | 1 | laforge | "PIC24" -> "Host PC" [ label = "USB" ] |
52 | 7 | laforge | } |
53 | 8 | laforge | }} |
54 | 7 | laforge | |
55 | h3. Image |
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57 | 9 | laforge | !fcdp_pcb.jpg! |
58 | 2 | laforge | |
59 | 7 | laforge | h2. Software |
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62 | 9 | laforge | The [[osmocomtetra:|OsmocomTETRA]] repository contains a demodulator script called *fcdp-tetra_demod.py* that can be used with the FCDP. |
63 | 1 | laforge | You have to use the 'qthid' application provided with the FCDP in order to tune to the respective tetra carrier frequency. |