# What do Sdist and Ldist in the databot bluetooth spec measure?

**URL:** <https://community.droneblocks.io/t/what-do-sdist-and-ldist-in-the-databot-bluetooth-spec-measure/803>\
**Category:** databot\
**Created:** [March 11, 2023, 4:17pm UTC](https://community.droneblocks.io/t/what-do-sdist-and-ldist-in-the-databot-bluetooth-spec-measure/803 "2023-03-11T16:17:27Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![pat.ryan](https://avatars.discourse-cdn.com/v4/letter/p/bcef8e/32.png) [@pat.ryan](https://community.droneblocks.io/u/pat.ryan)\
**Post date:** [March 11, 2023, 4:17pm UTC](https://community.droneblocks.io/t/what-do-sdist-and-ldist-in-the-databot-bluetooth-spec-measure/803/1 "2023-03-11T16:17:28Z")

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Hi Everyone  
I am looking at some of the bluetooth settings for the databot and I see ‘Sdist’ and ‘Ldist’ but I am not sure what they measure. Does anyone have any insight?

Also regardless of which one I set, the response comes back with the same response key, so it seems like you can only have one set to return data at a time, is that correct?

Thanks

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**Author:** ![dbaldwin](https://avatars.discourse-cdn.com/v4/letter/d/d2c977/32.png) [@dbaldwin](https://community.droneblocks.io/u/dbaldwin)\
**Post date:** [March 13, 2023, 5:53pm UTC](https://community.droneblocks.io/t/what-do-sdist-and-ldist-in-the-databot-bluetooth-spec-measure/803/2 "2023-03-13T17:53:06Z")

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These are related to the time of flight sensor that measures distance. SDist representing “short distance” and LDist measuring “long distance”. Check this out:

> The VL53L1X offers three distance modes: short, medium, and long. Long distance mode allows the longest possible ranging distance of 4 m, but the maximum range is significantly affected by ambient light. Short distance mode is mostly immune to ambient light, but the maximum ranging distance is typically limited to 1.3 m (4.4 ft). The maximum sampling rate in short distance mode is 50 Hz while the maximum sampling rate for medium and long distance modes is 30 Hz. Performance can be improved in all modes by using lower sampling rates and longer timing budgets (as can be seen in the figure above).

From here:

> **[Pololu - VL53L1X Time-of-Flight Distance Sensor Carrier with Voltage...](https://www.pololu.com/product/3415)**
>
> This sensor is a carrier/breakout board for ST’s VL53L1X laser-ranging sensor, which offers fast and accurate ranging up to 4 m. It uses the time of flight (ToF) of invisible, eye-safe laser pulses to measure absolute distances independent of...

and here is a code example from the databot repo:

> <https://github.com/arbotics-llc/databot_ESP32/blob/4ffdf1678f2eeecb20d00f165f0e9cc78383c278/examples/Sensors/databot_distance/databot_distance.ino#L25>

This example uses the long distance range. If it were up to me I would just go with Ldist unless someone on the databot team mentions otherwise.