User's Manual

Start signal Command | 0x40 Length Status CS

0x02 0x4E 0x01 1 Byte 1 Byte

Status:

0x00: Request successfully received and processed

0x01: Request not successful

To wake-up from shut down mode, a falling edge has to be applied to the WAKE-UP pin.

In this case, the module restarts such that all volatile settings are lost. As soon as it has

restarted a

CMD_RESET_IND

message is printed on the UART. Please note that in shut down

mode, the WAKE-UP pin has an internal pull-down to ensure the wake-up is not performed

accidentally due to a ﬂoating pin.

7.3.4 CMD_STANDBY_REQ

This command triggers the standby mode of the chip, a low power mode with RAM retention.

The standby mode is entered after the command conﬁrmation message is transmitted. The

UART interface is disabled in standby mode. The latency is smaller than the latency caused

by a complete restart of the module as done in the shut down mode.

Format:

Start signal Command Length CS

0x02 0x0F 0x00 0x0D

Response (

CMD_STANDBY_CNF

Start signal Command | 0x40 Length Status CS

0x02 0x4F 0x01 1 Byte 1 Byte

Status:

0x00: Request successfully received and processed

0x01: Request not successful

To wake-up from standby mode, a falling edge has to be applied to the WAKE-UP pin. Please

note that in standby mode, the WAKE-UP pin has an internal pull-down to ensure the wake-

up is not performed accidentally due to a ﬂoating pin. When a falling edge is detected, the

module wakes up but does not revert to factory settings as the RAM content is retained and

all volatile settings are kept. Upon being idle again, a

CMD_STANDBY_IND

message is printed

on the UART and the /RTS pin will show a low level.

7.3.5 CMD_STANDBY_IND

This message indicates that the module woke up from standby mode and is ready for oper-

ation.