PDoA at 10 Hz with more than 10 tags

Wireless Connectivity Ultra-Wideband
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1

Hi guys,

is there a way to allow more than 10 tags in the PDoA procedure with DWM1002 (node) & DWM1003 (tag), without decreasing ranging frequency?
According datasheets there are 10 TDMA slots, which can be assigned to tags in the “KList”.
In the tag_list.h source code file I found:

//maximum is limited by NUM_SLOTS; FCONFIG_SIZE and available memory size, see     default_config.h
#define MAX_KNOWN_TAG_LIST_SIZE                (9)  // MAX_KNOWN_TAG_LIST_SIZE =  DEFAULT_NUM_SLOTS - 1 as Slot 0 is for Beacon
#define MAX_DISCOVERED_TAG_LIST_SIZE           (9)  // MAX_DISCOVERED_TAG_LIST_SIZE =  DEFAULT_NUM_SLOTS - 1 as Slot 0 is for Beacon

Thus, I assume I have to increase MAX_KNOWN_TAG_LIST_SIZE. This constant depends on the slot configuration in default_config.h :

#define DEFAULT_SLOT_PERIOD_MS      10       /**< Slot period (ms), the best of what the implementation can achieve */
#define DEFAULT_NUM_SLOTS           10      /**< Number of slots: cannot be shorter than (MAX_KNOWN_TAG_LIST_SIZE + 1) */
#define DEFAULT_SF_PERIOD_MS        100     /**< SuperFrame period: cannot be shorter than NUM_SLOTS*SLOT_PERIOD */

Since DEFAULT_NUM_SLOTS = DEFAULT_SF_PERIOD_MS / DEFAULT_SLOT_PERIOD_MS and the slot period is already “the best of what the implementation can achieve” (…with this hardware?), it is not possible to increase the amount of tags within the PDoA system without decreasing the ranging frequency (100ms SuperFrame --> 10Hz). Or is there a way to decrease the default slot period?

2

This config is a safe option. Best way is to rewrite the Example application and optimize its flow. It is written for your understanding of the processes, not in mind to use 100% of the speed possible…

You also would want to experiment with other timing parameters. And of course use the compile option -O3.

On another HW I have the following config, which gave me 20 tags.
/* Slot configuration */
#define DEFAULT_SLOT_PERIOD_MS 5
#define DEFAULT_NUM_SLOTS 20
#define DEFAULT_SF_PERIOD_MS 100
#define DEFAULT_TAG_POLL_TX_RESPONSE_RX_US (700)
#define DEFAULT_TAG_POLL_TX_FINAL_TX_US (2000)