Let's look at the current consumption of the STEVAL-IDB007V1

littleshrimp

Let's look at the current consumption of the STEVAL-IDB007V1 [Copy link]

 

Test method, disconnect the JP2 jumper, and use an external power supply to power JP2 pin 2VBLUE342912[/attach]

The devices using VBLUE power supply include 2 sensors and BlueNRG-1

The current of the 2 sensors LPS25HB Power Down is 1uA, LSM6DS3 Power The current when Down is 6uA

The actual measured current is the current of the sensor Power Down + BlueNRG-1

The default transmit power of BLE_Beacon is -2dBm in the example. The broadcast interval is 100ms.

The actual test idle current when not transmitting is 9.68uA

The current when transmitting is 7.14mA,Because the ammeter sampling rate is low, the current may be inaccurate when measuring short pulses

[a The transmission time is about 3ms (the sampling rate when measuring current is limited and cannot show the current change during actual transmission)339863For more information about the low power consumption of BlueNRG-1, please refer to the official document "AN4820: BlueNRG-1 and BlueNRG-2 low powermodes》

The document gives a more accurate current change

http://www.st.com/resource/en/application_note/dm00263007.pdf

2The interval between broadcasts is about 106ms

Change the transmit power in the code to -18dBm (BlueNRG-1 only has High Power mode, the actual transmit power will be automatically set to -14dBm)

The test transmission current is about 5.38mA 339867-18dBm The average current when the broadcast interval is 100ms is 115.73uA

Change the broadcast interval to2s

-18dBmThe average current when the broadcast interval is2s is15.14uA, and the use of0.1Fsupercapacitor can work3[ 4 hours or more

In actual use, it is also necessary to addADC and timer sensor modules. The average current will increase appropriately. The working current can be spread by reducing the number of broadcasts. 0)]Pay special attention

In low power mode, GPIOneeds to be "specially handled", otherwise the sleep current will be unstable

In low power mode, the GPIOclock will be turned off, and the GPIOcannot be modified to output or pull up or down to stabilize the current

through code ]When using peripheral circuits to handle "idle" GPIO, it is necessary to combine the circuit in the schematic diagram. For example, when BlueNRG-1 is connected to LSM6DS3's SPI interface, it is not idle and needs to be processed.

0pt]Do "special processing", otherwise the sleep current will be unstable. In low power mode, the GPIO clock will be turned off, and the GPIO cannot be modified to output or pull up and down to stabilize the current through code. Use peripheral circuits to handle "idle" GPIO. When , it is necessary to combine the circuit in the schematic diagram. For example, BlueNRG-1 connects LSM6DS3 SPI interface, although it is not idle, it also needs to be processed

[attach] 339871[/attach]

0pt]Do "special processing", otherwise the sleep current will be unstable. In low power mode, the GPIO clock will be turned off, and the GPIO cannot be modified to output or pull up and down to stabilize the current through code. Use peripheral circuits to handle "idle" GPIO. When , it is necessary to combine the circuit in the schematic diagram. For example, BlueNRG-1 connects LSM6DS3 SPI interface, although it is not idle, it also needs to be processed

[attach] 339871[/attach]

gs001588

Pictures speak louder than words. They are all measured waveforms, combining theory with practice, with reason and evidence, and are credible.

littleshrimp

gs001588 posted on 2018-1-12 17:23 Pictures speak louder than words. They are all measured waveforms, combining theory with practice, with reason and evidence, and are credible.

What stage have you reached in your challenge?

cruelfox

Hey, what instrument is used to measure this current?

littleshrimp

cruelfox posted on 2018-1-12 17:36 Hey, what instrument is used to sample this current?

silabs EFM32 development board

忘归尘

"Using a 0.1uF supercapacitor can work for 3 or 4 hours" is not true. 0.1uF Farad capacitor?

littleshrimp

Wang Guichen posted on 2018-1-15 08:27 “Using a 0.1uF super capacitor can work for 3 or 4 hours” is not right. 0.1uF Farad capacitor?

I wrote it wrong, it should be 0.1F

zhangxpid

Hello, in low power mode 3, after power on, the serial port keeps printing WAKEUP Reason = POR, as if it is always being woken up, and the power consumption is relatively high, but this situation only happens occasionally (the power consumption may be different when the same code is tested twice), which should be the situation you are talking about. If it is practical, adding a pull-up resistor does not seem to be reasonable. Can you please ask if there are other methods besides external pull-up resistors?

littleshrimp

I later found out that the specific reason was caused by LSM6DS3 and had nothing to do with bluenrg