533f9ee332
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This commit allows to synchronise multiple HackRFs with a synchronisation error **below 1 sampling period**
> WARNING: Use this at your own risk. If you don't know what you are doing you may damage your HackRF.
> The author takes no responsability for potential damages
Usage example: synchronise two HackRFs
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1. Chose the master HackRF which will send the synchronisation pulse (HackRF0). HackRF1 will represent the slave hackrf.
2. Retreive the serial number of both HackRFs using `hackrf_info`
3. Use a wire to connect `SYNC_CMD` of HackRF0 to `SYNC_IN` of HackRF0 and HackRF1
4. Run `hackrf_transfer` with the argument `-H 1` to enable hardware synchronisation:
```
$ hackrf_tranfer ... -r rec1.bin -d HackRF1_serial -H 1 | hackrf_transfer ... -r rec0.bin -d HackRF0_serial -H 1
```
rec0.bin and rec1.bin will have a time offset below 1 sampling period.
The 1PPS output of GNSS receivers can be used to synchronise HackRFs even if they are far from each other.
>DON'T APPLY INCOMPATIBLE VOLTAGE LEVELS TO THE CPLD PINS
Signal | Header |Pin | Description
-------|--------|----|------------
`SYNC_IN` | P28 | 16 | Synchronisation pulse input
`SYNC_CMD` | P28 | 15 | Synchronisation pulse output
Note:
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I had to remove CPLD-based decimation to use a GPIO for enabling hardware.
More info:
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[M. Bartolucci, J. A. Del Peral-Rosado, R. Estatuet-Castillo, J. A. Garcia-Molina, M. Crisci and G. E. Corazza, "Synchronisation of low-cost open source SDRs for navigation applications," 2016 8th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC), Noordwijk, 2016, pp. 1-7.](http://ieeexplore.ieee.org/document/7849328/)
[Alternative link](http://spcomnav.uab.es/docs/conferences/Bartolucci_NAVITEC_2016.pdf)
CPLD interface between LPC43xx microcontroller SGPIO peripheral and MAX5864 RF codec.
CPLD-based triggered capture
To build this VHDL project and produce an SVF file for flashing the CPLD:
- Xilinx WebPACK 13.4 for Windows or Linux.
Generate an XSVF
After generating a programming file:
- In the ISE Project Navigator, "Processes: top - Behavioral" pane, double-click "Configure Target Device".
- Click "OK" to open iMPACT.
- Ctrl-N to create a "New Project".
- "Yes" to automatically create and save a project file.
- Select "Prepare a Boundary-Scan File", choose "XSVF".
- Select file name "default.xsvf".
- Click "OK" to start adding devices.
- Assign new configuration file: "top.jed".
- Right-click the "xc2c64a top.jed" icon and select "Erase". Accept defaults.
- Right-click the "xc2c64a top.jed" icon and select "Program".
- Right-click the "xc2c64a top.jed" icon and select "Verify".
- Choose menu "Output" -> "XSVF File" -> "Stop Writing to XSVF File".
- Close iMPACT.
To Program
$ hackrf_cpldjtag -x default.xsvf