RF96 datasheet(109/121 Pages) HOPE

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Page 109

RF96/97/98

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WIRELESS & SENSING

PRELIMINARY

DATASHEET

7.2.2. Manual Reset

A manual reset of the RF96/97/98 is possible even for applications in which VDD cannot be physically disconnected. Pin

7 should be pulled low for a hundred microseconds, and then released. The user should then wait for 5 ms before using the

chip.

Figure 43. Manual Reset Timing Diagram

Note

whilst pin 7 is driven low, an over current consumption of up to one milliampere can be seen on VDD.

7.3. Top Sequencer: Listen Mode Examples

In this scenario, the circuit spends most of the time in Idle mode, during which only the RC oscillator is on. Periodically the

receiver wakes up and looks for incoming signal. If a wanted signal is detected, the receiver is kept on and data are

analyzed. Otherwise, if there was no wanted signal for a defined period of time, the receiver is switched off until the next

receive period.

During Listen mode, the Radio stays most of the time in a Low Power mode, resulting in very low average power

consumption. The general timing diagram of this scenario is given in Figure 44.

Listen m ode : principle

Receive

Idle ( Sleep + RC )

Receive

Idle

Figure 44. Listen Mode: Principle

An interrupt request is generated on a packet reception. The user can then take appropriate action.

Depending on the application and environment, there are several ways to implement Listen mode:

 Wake on a PreambleDetect interrupt

 Wake on a SyncAddress interrupt

 Wake on a PayloadReady interrupt

7.3.1. Wake on Preamble Interrupt

In one possible scenario, the sequencer polls for a Preamble detection. If a preamble signal is detected, the sequencer is

switched off and the circuit stays in Receive mode until the user switches modes. Otherwise, the receiver is switched off

until the next Rx period.

RF96 Datasheet(PDF) 109 Page - HOPE Microelectronics CO., Ltd.