Arduino for STM32

Hi. I try to reduce the power consumption of Arducam mini 2MP (OV2640) connected to my STM32L476 board. I can take it to Standby mode with the following code. However, it still consumes about 40 mA in standby mode which is much more than what it should be (about 1 mA according to the datasheet)! Does anybody know what is wrong with this simple task?

Many thanks in advance

mebab wrote: ↑Fri Jun 18, 2021 4:58 am Hi. I try to reduce the power consumption of Arducam mini 2MP (OV2640) connected to my STM32L476 board. I can take it to Standby mode with the following code. However, it still consumes about 40 mA in standby mode which is much more than what it should be (about 1 mA according to the datasheet)!

Code: Select all

    myCAM.set_bit(ARDUCHIP_GPIO,GPIO_PWDN_MASK);

Does anybody know what is wrong with this simple task?

Many thanks in advance

Some battery power device need save power when in the idle status, the ArduCAM offers the low power mode to reduce power consumption, by shutdown the sensor and memory circuits.

Thanks @StevenD. I have tested either of the Standby and Shutdown modes. They look about the same in terms of power consumption! Do you have a different estimation of the power consumption in shutdown mode?

@mebab did you find a solution to this? I was wondering whether you are measuring the current directly at the ArduCAM pin? I'm thinking, perhaps you have current flowing through the I2C pins (or some of the SPI pins). Although you have turned-off the supply, I'm guessing the pull-ups of teh I2C pins are still connected to the supply, therefore there will be current flow.

In fact, I am measuring the consumed current sunk from the power supply (battery). From the Electrical Current profile on the scope, I know which part is due to CAM operation. You just need to disconnect and measure the current consumption without CAM to know how the CAM consumes the power.
I decided to disconnect the CAM Power when I don't need it by using hardware. I used a Darlington transistor to switch the power on or off to the CAM. Please note that the collector-emitter voltage drop should be less in order for CAM to be able to operate properly. In this case, you have to re-define CAM again whenever you turn it ON. I wish they had made a software-based method to minimize the power. However, it looks like there is no other software solution yet.