• State Verified Answer
  • Replies 6 replies
  • Subscribers 62 subscribers
  • Views 2964 views
  • Users 0 members are here
Attachments (0)
Nordic Case Info
  • Case ID: 106723
Options
This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts

Timing of central RX and peripheral TX

muhkuhns

I got an easy but fundamental question: How to make sure that the central sees the advertising package of the peripheral..

For example when the peripheral advertises only every 5 seconds.. The centrals scan windows would have to be >5seconds? (and also the scan interval) So ongoing RX current??? (Or does the RX current only occurs when it actually receives an advertising packet?)

If they would establish a connection.. could I decrease the current consumption of the central while not increasing the current consumption of the peripherals? (Do they synchronize their RX/TX or something?)

Parents
  • 0

    @muhkuhns: As shibshab mentioned there is no way to guarantee a packet will be received even if the central was listening on that channel due to interference.

    If we leave interference & noise aside, what you need to make sure that the central can catch all the advertising packet is to listen all the time. Usually the peripheral will advertise in all 3 channels. The S120 listen to each of them one at a time (rotating between 3 channels). So what you need to do is to configure the scan windows equal to scan interval. This will make the scanner scan all the time. It doesn't have to be 5 second scan windows and scan interval. Just set the scan window = scan interval. Note that to make sure the scanner listen all the time, there should be no connection should be active on S120 when scanning.

    When connected, the scanner doesn't have to listen all the time any more. They synchronize and agree on timing windows and channel maps to continue.

Reply
  • 0

    @muhkuhns: As shibshab mentioned there is no way to guarantee a packet will be received even if the central was listening on that channel due to interference.

    If we leave interference & noise aside, what you need to make sure that the central can catch all the advertising packet is to listen all the time. Usually the peripheral will advertise in all 3 channels. The S120 listen to each of them one at a time (rotating between 3 channels). So what you need to do is to configure the scan windows equal to scan interval. This will make the scanner scan all the time. It doesn't have to be 5 second scan windows and scan interval. Just set the scan window = scan interval. Note that to make sure the scanner listen all the time, there should be no connection should be active on S120 when scanning.

    When connected, the scanner doesn't have to listen all the time any more. They synchronize and agree on timing windows and channel maps to continue.

Children
Related