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Topic: Idle command to Bluetooth WT-11 of the Arduino BT? (Read 651 times) previous topic - next topic


I am searching for command to put the BlueTooth into Idle mode (Arduino Alpha) to save the power, but could not find it anywhere.

- Can someone help me on it?
- If YES, then what is the command to wake the Bluetooth WT-11 up later?

Thanks to any help  :-?



Mike T

Jul 07, 2009, 11:58 am Last Edit: Jul 07, 2009, 11:58 am by nospam2000 Reason: 1
Hi Curious,

I am searching for command to put the BlueTooth into Idle mode

You can use the deep sleep mode. I never used it myself, so this info is just from the iWrap 2.2.0 User Guide. To enable the deep sleep mode, you have to set bit 4 in CONTROL CONFIG:

SET CONTROL CONFIG {configuration_value}

Bit 4
"Deep sleep enabled". If this bit is set, 'Deep sleep' power
saving mode will be used. Deep sleep is an aggressive power
saving mode used when there are no connections.

The meaning of the other bits:
Code: [Select]
 // Bit 0 = 1  RSSI value will be visible in the inquiry results
 // Bit 1 = 0  reserved
 // Bit 2 = 1  Interlaced inquiry scan
 // Bit 3 = 1  Interlaced page scan
 // Bit 4 = 1  Deep sleep
 // Bit 5 = 1  Bluetooth address in CONNECT event
 // Bit 6 = 0  reserved
 // Bit 7 = 0  Displays the PAIR event after successful pairing
 // Bit 8 = 0  Enables SCO links. This bit must be 1 if you use audio profiles.
 // Bit 9 = 0  reserved
 // Bit 10= 0  reserved
 // Bit 11= 0  Enables interactive pairing mode
 // Bit 12= 1  iWRAP randomly replaces one of the existing pairings,
 //   when 17th pairing is done (max number of pairings is 16)

This results in the value 103D:
Code: [Select]

You can also activate it directly using the SLEEP command:
The SLEEP command will force deep sleep on. After issuing this command, the module will enter deep sleep until a Bluetooth connection is received or something is received from the UART interface in command mode. The SLEEP command will also work when there are one or more active connections and iWRAP is in command mode.

- If YES, then what is the command to wake the Bluetooth WT-11 up later?

It seems that it awakes automatically with the first character received from UART:

If deep sleep is used, the first character written to UART wakes the module from the 'Deep sleep' and that's why the character is lost. There are two ways to overcome this problem:
1. If you command iWRAP with a micro controller or processor, add 'space' or 'line break' characters in front of every command.
2. In PSTool, set parameter 'EXIT deep sleep on CTS line activity' to TRUE. Now 'Deep sleep' does not lose characters any more, but current consumption will increase

If you are using 'Deep sleep' the minimum baud rate that can be used is 19200. Lower baud rates will corrupt the data.

To enable automatic power saving during connections, "SET BT SNIFF" withappropriate parameters can be used.


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