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doc:lps:toda3 [2018-06-15 08:53]
kristoffer
doc:lps:toda3 [2018-11-06 14:10] (current)
arnaud
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 ====== TDoA 3 set up ====== ====== TDoA 3 set up ======
  
-<WRAP center round tip 80%> +TDoA 3 is part of the official Crazyflie and LPS Node firmware releases since 2018.10.
-**NOTE** +
-The TDoA3 mode is experimentalThe protocol and implementation might change but is fairly stable. +
-</​WRAP>​+
  
-===== Compile and flash ===== +The Crazyflie ​will automatically detect that the positioning system is using TDoA3 and switch to the correct ​mode. 
- +If you want to force the Crazyflie ​to use TDoA3 on startup, use the LPS_TDOA3_ENABLE=1 compile option
-To try it out you will have to do the following:​ +
- +
-==== The Crazyflie ​==== +
- +
-  * Get the latest source code for the firmware from [[https://​github.com/​bitcraze/​crazyflie-firmware]]. Make sure the git submodules are updated +
-  * Compile for TDoA3 and force the TDoA mode with ''​make "​EXTRA_CFLAGS=-DLPS_TDOA_USE_V3 -DLPS_TDOA_ENABLE"''​ +
-  * Flash the Crazyflie ​with ''​make cload''​ script.+
  
 ==== The LPS Nodes ==== ==== The LPS Nodes ====
  
-  * Get the latests source code for the firmware from [[https://​github.com/​bitcraze/​lps-node-firmware]]. Make sure the git submodules are updated 
-  * Compile 
-  * Flash the nodes using ''​make dfu''​ 
   * Configure the Nodes as anchors, and set the mode to TDoA 3   * Configure the Nodes as anchors, and set the mode to TDoA 3
-  * Anchor ​positions ​can be set using the python client (0 - 7) but if you have more anchors you will have toools/​lpp/​set_positions.py script.py+  * Set anchor ​positions, see below.
  
 ===== Setting anchor positions ===== ===== Setting anchor positions =====
  
-Anchor positions can be set by the python client ​but it only supports ids 0-7. If you want to use more anchors there is a tool that can be used. +Anchor positions can be set by the python client ​or the tool in the lps-node-firmware repo. 
- +You might have to move the Crazyflie close to all anchors to transfer the positions from the Crazyflie
-The tool uses a Crazyflie as a bridge to transmit UWB messages to the anchors. When it is started it transmits positions for all anchors over and over, +
- +
-The tool is somewhat hackish and could use some updates, for instance the Crazyflie radio address is hardcoded ​in the scriptBe prepared ​to modify the script... +
- +
-  * Create a file with your anchor positions, see tools/​lpp/​positions_example.yaml +
-  * Start the Crazyflie +
-  * Pipe the position file into the tool ''​cat my_position_file.yaml | python3 tools/​lpp/​set_positions.py''​ +
-  * Move the Crazyflie close to all anchors to transfer the positions +
- +
-===== Sniffing ===== +
- +
-If an anchor is configured to act as a sniffer, it can be used to listen to the UWB messages in the system. To set an anchor to sniffer mode, connect via USB. +
- +
-==== Basic sniffing ==== +
- +
-Connect the sniffer via USB and check in /dev which port that it uses. Use this as the first argument +
-The second argument is the output format, use yaml +
-example: ''​python3 tools/​sniffer/​sniffer_binary.py /​dev/​tty.usbmodem1421 yaml''​ +
- +
-==== TDoA 3 parsing ==== +
- +
-Pipe the yaml into the TDoA 3 decoder to see TDoA 3 data unpacked +
- +
-example: ''​python3 tools/​sniffer/​sniffer_binary.py /​dev/​tty.usbmodem1421 yaml | python3 tools/​sniffer/​tdoa3_decoder.py''​ +
- +
-This will show all data that the sniffer receives. To limit the output it is possible to filter which anchors to show. Add one or more ids at the end to only show data from only these anchors. +
- +
-example: ''​python3 tools/​sniffer/​sniffer_binary.py /​dev/​tty.usbmodem1421 yaml | python3 tools/​sniffer/​tdoa3_decoder.py 2 3''​ +
- +
-==== Time of flight and anchor to anchor distance ==== +
- +
-By piping ​the TDoA 3 data into the TOF tool, the measured anchor to anchor distances will be displayed. By adding the '​m'​ argument the output will be in meters instead of UWB clock ticks. +
- +
-example: ''​python3 tools/​sniffer/​sniffer_binary.py /​dev/​tty.usbmodem1421 yaml | python3 tools/​sniffer/​tdoa3_decoder.py | python3 tools/​sniffer/​tdoa3_tof.py m''​+
  
 +All the anchors work in the same coordinate system, so you need to choose a common origin for your system. Try to expand your system step by step, testing it at each step to catch problem when they start to happen.
  
 ===== 2D positioning ===== ===== 2D positioning =====
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 Recompile the Crazyflie firmware using the LPS_2D_POSITION_HEIGHT compile flag set to the desired Z. Recompile the Crazyflie firmware using the LPS_2D_POSITION_HEIGHT compile flag set to the desired Z.
-For instance ''​make "​EXTRA_CFLAGS=-DLPS_TDOA_USE_V3 -DLPS_TDOA_ENABLE ​-DLPS_2D_POSITION_HEIGHT=1.2"''​ if the tag will be located at 1.2 meters height.+For instance ''​make "​EXTRA_CFLAGS=-DLPS_2D_POSITION_HEIGHT=1.2"''​ if the tag will be located at 1.2 meters height.
  
 ===== Longer range and lower bitrate ===== ===== Longer range and lower bitrate =====
 +
 +Note: this is experimental functionality that is not fully tested or might not work as expected.
  
 In this mode the UWB bitrate is lower and the data of messages can be read at a longer distance. The packet rate will be reduced though. In this mode the UWB bitrate is lower and the data of messages can be read at a longer distance. The packet rate will be reduced though.
  
-Recompile ​both Crazyflie ​and anchors ​with the LPS_LONGER_RANGE compile flag.+Recompile ​the Crazyflie ​firmware ​with the LPS_LONGER_RANGE compile flag. 
 + 
 +Example: ''​make "​EXTRA_CFLAGS=-DLPS_LONGER_RANGE"''​
  
-Example: ''​make "​EXTRA_CFLAGS=-DLPS_TDOA_USE_V3 -DLPS_TDOA_ENABLE -DLPS_LONGER_RANGE"''​+There is a setting for the bitrate in the Anchor configuration when connecting using USB.
  
 ===== Longer preamble ===== ===== Longer preamble =====
 +
 +Note: this is experimental functionality that is not fully tested or might not work as expected.
  
 It is possible to use a longer preamble, this will also reduce packet rate. There is no compile flag for this setting, it requires some code modifications in the Crazyflie and the anchors. It is possible to use a longer preamble, this will also reduce packet rate. There is no compile flag for this setting, it requires some code modifications in the Crazyflie and the anchors.
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 ==== The LPS Nodes ==== ==== The LPS Nodes ====
  
-  * Find the src/uwb.c file +  * There is a configuration setting for the preamble length 
-  * Locate ​the call to dwEnableMode() + 
-  * Change ​the second ​argument ​to MODE_LONGDATA_MID_ACCURACY +===== Sniffing ===== 
-  * Find the src/uwb_tdoa_anchor3.c file + 
-  * Locate ​the line where PREAMBLE_LENGTH_S is defined +Sniffing the system is useful when you want to start digging into the radio messages exchanged between the anchor. It is a debug functionality
-  * Change ​it to 1024 bits#define PREAMBLE_LENGTH_S ( 1024 * 1017.63e-9 ) + 
-  * Compile ​and flash+If an anchor is configured to act as a sniffer, it can be used to listen to the UWB messages in the system. To set an anchor ​to sniffer mode, connect via USB and configure it to sniffer mode. 
 + 
 +==== Basic sniffing ==== 
 + 
 +Connect ​the sniffer via USB and check in /dev which port that it uses. Use this as the first argument 
 +The second argument is the output format, use yaml 
 +example: ''​python3 tools/​sniffer/​sniffer_binary.py /dev/tty.usbmodem1421 yaml''​ 
 + 
 +==== TDoA 3 parsing ==== 
 + 
 +Pipe the yaml into the TDoA 3 decoder to see TDoA 3 data unpacked 
 + 
 +example: ''​python3 tools/​sniffer/​sniffer_binary.py /​dev/​tty.usbmodem1421 yaml | python3 tools/​sniffer/​tdoa3_decoder.py''​ 
 + 
 +This will show all data that the sniffer receives. To limit the output ​it is possible ​to filter which anchors to show. Add one or more ids at the end to only show data from only these anchors. 
 + 
 +example''​python3 tools/​sniffer/​sniffer_binary.py /​dev/​tty.usbmodem1421 yaml | python3 tools/​sniffer/​tdoa3_decoder.py 2 3''​ 
 + 
 +==== Time of flight ​and anchor to anchor distance ==== 
 + 
 +By piping the TDoA 3 data into the TOF tool, the measured anchor to anchor distances will be displayed. By adding the '​m'​ argument the output will be in meters instead of UWB clock ticks. 
 + 
 +example: ''​python3 tools/​sniffer/​sniffer_binary.py /​dev/​tty.usbmodem1421 yaml | python3 tools/​sniffer/​tdoa3_decoder.py | python3 tools/​sniffer/​tdoa3_tof.py m''​
  
  
doc/lps/toda3.1529045626.txt.gz · Last modified: 2018-06-15 08:53 by kristoffer