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What is scan window in BLE?
Scan Window Defines how long to scan at each interval. This variable is defined in units of 625us and and has a range between 4 and 16384. By default is set to 50, which is equivalent to 50 * 625 us = 31.250 ms. It must be equal or smaller than scan interval.
What is scan interval?
The Scan Interval or Scan Time refers to the amount of Time it takes the Programmable Controller to evaluate a ladder logic program one time. The Scan Interval is typically in the low-millisecond range.
How does a BLE scan work?
The BLE peripheral receives the Scan Request and responds with a Scan response. Both iOS, Android and other systems issue Scan Requests automatically without user intervention when scanning. Your device will therefore receive these requests if it has it enabled.
What is a connection interval?
The connection interval is the amount of time between two connection events in units of 1.25 ms. The connection interval can range from a minimum value of 6 (7.5 ms) to a maximum of 3200 (4.0 s).
What is Gap and GATT in BLE?
GAP and GATT are complementary connection protocols that perform in parallel on BLE devices. GAP, the Generic Access Profile, defines the framework for allowing device discovery, security, connectivity and the related network topology, and it is thus mandatory for a BLE device.
What is a BLE PDU?
For data packets it consists of 32 bit random value generated by BLE device in “initiating state”. The same value is used in a “connection request (CONNECT_REQ)” message. PDU:It consists of either “advertising channel PDU” or “data channel PDU” as defined in the figure.
Is there a better way to set ble scan interval?
Is there a better way? You are free to control the equivalent if scan window and interval yourself in higher-level code by starting and stopping scanning. This is exactly what the open source Android Beacon Library does with its equivalent configurable parameters:
What is the difference between scan window, interval?
The Scan_Window configuration parameter defines the amount of time for the duration of the scan. The Inquiry_Scan_Window can only be less than or equal to the Scan_Interval.
What are the parameters of Bluetooth Low energy scanning?
Scanning Basics Scan Parameter Description Range Scan Interval Interval between the start of two consec 10 ms to 10.24 s Scan Window The duration in which the Link Layer sca 10 ms to 10.24 s Scan Duration The duration in which the device stays i 10 ms to infinity
What is the scan interval for Bluetooth 4.0?
According to the Bluetooth 4.0 core specification the time period of ‘advertising events’ are as shown below for the different types of advertising packets: ADV_IND: General connectable and scannable advertisement packets’ time period ranges from 20 ms to 10.24s in steps of 0.625ms.