Power Management

Audio Agent is configured to reduce the power consumption in both connected and not connected state.

Not Connected

By default, if Audio Agent is not connected, it will be connectable and stays discoverable for a certain amount of time (configurable). If connection is lost, Audio Agent will attempt to reconnect the number of times specified by the MAX_REC parameter. After that, and if Deep Sleep is enabled, Audio Agent will go into Deep sleep mode (a very low power consumption mode). In this mode Audio Agent will not be discoverable or able to accept any connection. This allows reducing current consumption to a minimum when the device is not connected and not operational. In order for Audio Agent to get out of this mode, a random character has to be sent through the UART. After a 5ms wake-up time the module will be operational again. If GPIO commands are enabled, any GPIO change will also get Audio Agent out Deep Sleep.

Note: Waking Audio Agent up will not disable Deep Sleep and the module will go back into Deep Sleep after the command is executed. It is recommended if Deep Sleep is enabled, to always send a carriage return before a command. This will not return anything if Audio Agent wakes up from Deep Sleep and will return “ERROR 0x0012” if Audio Agent is already awake. After sending the carriage return, wait for 5ms (the chip wake-up time) and then send the command. The chip will stay awake for 1s after the last byte is received on the UART.

Connected

When Audio Agent is connected, it is set-up to reduce power consumption while maintaining the connection. In this state, Audio Agent will automatically establish a link policy to allow it to reduce power consumption while still being able to receive link updates.

Note: If Deep Sleep is enabled, Audio Agent will go into deep sleep after 1000ms of no activity.

Battery configuration

The battery configuration is in BATT_CONFIG. The value of the charging current is configurable (between 0 and 200 mA) and three levels define the battery behavior.

- Vbat Battery Voltage:

When the voltage drops to the critical voltage (145*20=2900mV by default), Audio Agent automatically shuts down to preserve remaining power.

- Vchg Threshold Voltage:

Audio Agent will stop charging if the value is superior to this limit (4250mV by default).

- Vthm Thermistor Threshold Voltage:

The Vthm is on AIO1 1 input. Audio Agent will not charge if the value is superior to this limit (1350mV by default)

1

AIO readings saturate above 1.35V