5.3.2.8 Set Deep Sleep Advertising (SDO,<0,1>,<hex16>)

Format: SDO,<0,1>,<hex16>

The Deep Sleep Advertising (DSADV) in the RNBD451 module is configurable using the SDO command. The SDO command accepts two input parameters. The first parameter is a single digit value that determines the enabling/disabling of the deep sleep advertising feature, and it expects two bytes length as the second input parameter. The value ‘1’ enables the deep sleep advertisement. When the deep sleep advertisement is enabled, then the UART is not operational to save the power consumption. If the first parameter value is ‘0’, the RNBD451 module runs without DSADV, and UART is operational all time.

It is necessary to wake up UART by pulling UART_RX_IND (UART RX Indication, PB4) pin low from the host MCU before the host MCU transmits data to the RNBD451 module.

The second input parameter indicates the deep sleep advertisement interval with a 0.625 ms time unit.

With deep sleep advertisement enabled, the RNBD451 module wakes up and advertises once for every set interval time. After the single advertisement, the RNBD451 module enters into deep sleep again until it gets connected with a central.

If the host MCU wants to send a command during the time when the RNBD451 module is operating in deep sleep advertising, then the host MCU must wake up the RNBD451 module. Which means, the UART_RX_IND (UART RX Indication, PB4) must be active prior to sending any UART data.
Note: The wake-up time must be more than 25 ms.

If the DSADV interval setting is more than 400 ms, the RNBD451 module rejects DSADV. In this scenario, there is no power consumption advantage than normal Sleep mode, and the RNBD451 module rejects the DSADV. MCU can choose the normal Sleep mode command instead of the Low Power Control (SO) command. For more details, refer to 5.3.1.6 Low Power Control (SO,<0,1>).

Figure 5-3. Wake-Up RNBD451 from DSADV Timing Diagram
Note: T1: The time prior to UART data. This time must be more than 25 ms.
Default: 0, 0000 // DSADV mode is disable
Example: SDO,1,0640 // Set DSADV enable for interval 1s
Response: AOK

// Success

Err // Syntax error or invalid parameter