RT1062 sleep and idle questions

OpenMV Products
1

The RT1062 does not seem to support light sleep, so I am assuming machine.idle() and sensor.sleep() is the closest to a light sleep. However, I am unsure how to use idle, do I use the RTC wakeup with idle, or should I call sensor.sleep(True), machine.idle(), then time.sleep(n)?

Side question: how do we achieve the lowest power mode of 30uA? So far in deep sleep I am seeing about 1.6mA.

Thanks!

2

Hi, the battery charger draws 1.6mA. The 30uA is unlocked only on powering from the battery connector via a battery.

As for light sleep. There’s no support for this right now. Also, not sure if there’s a point. You kinda want to do all the work you need to do and then go back to deep sleep.

1 Like
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That makes sense about the using the battery header.

Regarding light sleep, there are timing situations where using camera sleep and light sleep to keep camera configuration state is more power efficient versus deep sleep and using the power during camera configuration.

I will crunch the numbers and if a camera sleep and light sleep configuration makes sense for my use case I will consider attempting to port the Teensy 4 Snooze library: Snooze/src/hal/TEENSY_40 at master · duff2013/Snooze · GitHub

Thanks, I am impressed with the cleanliness of the code and documentation!

4

Hi, if you disable the delays in the camera sensor API, a documented feature, you can go in and out of deep sleep and reset the camera state in less than a second. We had a customer explicitly ask us to make to make the camera wakeup fast and we got that down to 250ms with the OV5640 once the system boots.

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5

250ms is excellent!

I was looking at the Lepton init/reset code and noticed 1000ms delay that I might try to shorten and test. Also, something for a future revision, the Lepton breakout board pulls PWR_DWN_L high, but it would be nice if this was connected to a GPIO or at least a solderable pad so the user can place the Lepton in shutdown mode to save power for low frame rate use cases.

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PWR_DWN_L is connected to the PWDN pin on the camera header. When you do sensor.shutdown() it turns it off.