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doc:lps:twr-tdma [2017-07-18 15:39]
arnaud [Abstract]
doc:lps:twr-tdma [2017-07-19 11:38]
arnaud [Compiling Crazyflie for TWR-TDMA ranging]
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 In order to activate TWR-TDMA, you need to recompile the Crazyflie firmware. Add the following to 'tools/make/config.mk': In order to activate TWR-TDMA, you need to recompile the Crazyflie firmware. Add the following to 'tools/make/config.mk':
-<code>+<code make>
 LPS_TDMA_ENABLE=1 LPS_TDMA_ENABLE=1
 CFLAGS += -DTDMA_NSLOTS_BITS=1 CFLAGS += -DTDMA_NSLOTS_BITS=1
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   * **LPS_TDMA_ENABLE=1** Enable the TDMA mode for TWR   * **LPS_TDMA_ENABLE=1** Enable the TDMA mode for TWR
-  * **TDMA_NSLOTS_BITS=1** Configures 2 time slot (good for 2 tags). The number of time slot is 2^TDMA_NSLOTS_BITS +  * **TDMA_NSLOTS_BITS=1** Configures 2 time slot (good for 2 tags) per frame. The number of time slot per frame is 2^TDMA_NSLOTS_BITS 
-  * **TDMA_SLOT** Optionally hardcode the time slot. See bellow for time slot auto-configuration.+  * **TDMA_SLOT** Optionally hardcode the time slot. See bellow for time slot auto-configuration
  
 ===== Configuring time slots ===== ===== Configuring time slots =====
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 ===== System performance ===== ===== System performance =====
  
-TWR-TDMA is currently implemented with time slots of 4ms. Each time slot is used by one tag to range with one anchor. This means that the ranging rate is of //1/(0.004 * (2^TDMA_NSLOTS_BITS)// and the rate of update of the full system is //1/(0.004 * (2^TDMA_NSLOTS_BITS* nAnchors)// where nAnchors is the number of anchors in the system.+TWR-TDMA is currently implemented with time slots of 4ms. Each time slot is used by one tag to range with one anchor. This means that the ranging rate is of //1/(0.004 * 2^TDMA_NSLOTS_BITS)// and the rate of update of the full system is //1/(0.004 * 2^TDMA_NSLOTS_BITS * nAnchors)// where nAnchors is the number of anchors in the system.
  
-The more timeslots, the less often measurements can be used to estimate the tag position and so the performance of the position estimate will deteriorate. For a great number of tag the [[doc:lps:tdoa|TDoA]] mode is better suited.+The more timeslots per frame, the less often measurements can be used to estimate the tag position and so the performance of the position estimate will deteriorate. For a great number of tag the [[doc:lps:tdoa|TDoA]] mode is better suited.
doc/lps/twr-tdma.txt · Last modified: 2021-06-24 16:54 by kimberly