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gittemeier
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Last seen: 1 year 2 months ago
Joined: 2020-09-22 19:51
Extended sleep wake from BLE

Hi Dialog Team,

I'm interested in using your DA14531 in a low powered sensor application, and am especially interested in your Extended Sleep power mode. Can you maintain a BLE connection in this mode, and can receiving a BLE message wake you from this mode into the active state? In section 4.2.2.2 of the datasheet, it says "RAM is expected to be retained for ... keeping a BLE connection alive (stack variables or BLE data)", but later I can only find references to waking from a GPIO or a timer. 

If you can't wake from Extended Sleep by receiving a BLE message, what's the lowest power consumption state that you can wake from with a BLE message? Is the next best option "Receiver Active, CPU idle at 16MHz, DCDC on", 2.2mA? Can this current be decreased by powering down the baseband during idle periods, as mentioned in section 29 of the datasheet? 

If it's helpful, I'm planning to use a 3V coin cell to power this, and putting the DA14531 into buck mode.

Thanks,

Sarah

Device: 
Martin.Ge
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Last seen: 9 months 5 days ago
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Joined: 2020-01-06 06:51
Hi Sarah, 

Hi Sarah, 

1.Can you maintain a BLE connection in this mode​ : 

Sure, the BLE connection is maintained during the sleep mode.

2.can receiving a BLE message wake you from this mode into the active state? 

Yes. In the extended sleep mode, you can wake up the device by receiving BLE message/RTC timer/Timer1.

3. what's the lowest power consumption state that you can wake from with a BLE message?

As for my previous practice, power consumption is about 3 uA. You can verify this by following the toturial: 

http://lpccs-docs.dialog-semiconductor.com/DA14531_Sleep_Mode+/index.html

4. Is the next best option "Receiver Active, CPU idle at 16MHz, DCDC on", 2.2mA? Can this current be decreased by powering down the baseband during idle periods

Yes. This current value can be reduced by powering down the baseband. 

 

Best regards 

Martin

gittemeier
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Last seen: 1 year 2 months ago
Joined: 2020-09-22 19:51
Great, thanks for your quick

Great, thanks for your quick reply! Last clarification, what happens if the DA14531 is put into extended sleep mode, and the BLE connection is dropped? Can it reconnect later and then still wake up to a BLE message? For example, say someone sets up this sensor, connects to it with their phone, puts the module to sleep and leaves for a few days. When he comes back, will the DA14531 be able to reconnect to his phone and wake up from a BLE message? 

PM_Dialog
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Last seen: 2 days 8 hours ago
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Joined: 2018-02-08 11:03
Hi gittemeier,

Hi gittemeier,

This depend on how the disconnection is handled by your application code. Please a look at the SDK BLE example – once the device is disconnected from a peer device, the .app_on_disconnect  = user_app_on_disconnect, and the advertisement is started again.

Please keep in mind that the system can go into sleep mode between advertising or connection intervals and woken-up via the BLE Timer. Additionally, you configure it in permanent sleep mode (no BLE activity) – the ble_app_sleepmode examples demonstrates that functionality.

As soon as the chip wakes up or advertising again, you can connect it with a peer device.

Thanks, PM_Dialog