BLE modem sleep still needs much current

[ukrsms]

ESP-IDF version 3.2.2
I've studied the topic ble taking too much power on how to set up Bluetooth modem sleep with external 32.768kHz crystal and tried it by my own.
I enabled Enable Power Management
Enabled Tickless Idle
and set RTC clock source (External 32kHz crystal) as well as Bluetooth low power clock (External 32kHz crystal) in SDKConfig
Set MIN and MAX CPU frequency, enabled Light sleep with esp_pm_configure(&pm_config)
according to the instruction.
I connected the crystal according to the picture:

32k.JPG (25.52 KiB) Viewed 6962 times

In the test made by @mywang-espressif he got the average current about 2-3mA, however, in my case I got the current a bit lower than 30mA.

In order to define the cause I print locks in my task with esp_pm_dump_locks(stdout); and got the list:

• Lock stats:
  bt APB_FREQ_MAX 0 0
  btLS NO_LIGHT_SLEEP 0 1
  rtos1 CPU_FREQ_MAX 0 1
  rtos0 CPU_FREQ_MAX 0 0

If I am not wrong the second line means NO_LIGHT_SLEEP lock was acquired preventing the chip from going to light sleep (32kHz crystal is not used?). When looking in file bt.c (esp-idf\components\bt\) in order to find the lock I found a line I am confused with:

Code: Select all

static DRAM_ATTR esp_pm_lock_handle_t s_light_sleep_pm_lock; // pm_lock to prevent light sleep due to incompatibility currently

Does this mean the Modem sleep is not available?

Could someone confirm he was able to achieve 3mA consumption with BLE being active?

[kengster]

Hi! Did you figure out anything?
I am trying to reduce as much as possible the power consumption when using BLE. For my aplication I need to have always the BLE ON, so I need to avoid any kind of sleep that turns off the BLE. I am getting 70-80mA and that is to much for me.

I have seen that this could be reduced using an external crystal, but I am not sure how to do it.

I am also trying to figure out how to reduce the power consumption by deactivating other functions.

Have you got any recommendation?

Cheers,

Iker.

[lx393ale]

Hi @kengster,
Have you solved? I'm facing in the same problem.

Thank you

[moshesimon]

Hi guys,

I'm also struggling with this problem.

If anyone can help me out id be very grateful and happy to pay for your time.
please email at moshesimon4ever@gmail.com