Arduino Low power (with deep sleep) sample code for Notecard


Does anyone managed a low power (with deep sleep) arduino code sample that reads some sensor data and sends data over Notecard?


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I am looking for a sample code for long term battery operated sensor reading communications.

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Yes, I think that code will be very useful for all of us that want to use a Notecard in remote places and solar-powered. Especially for an ESP32.


Hello @iarakis,

Unfortunately, we do not have a low-power example ready to go, but we should. I’m will put together a very simple, low-power example to help people get started, and I will report back to this thread with a link.

You can provide feedback about the example here as well, and together we can make a simple but robust example for others to follow.

I’ll be speaking with you soon!


That would be great. Looking forward to it. In my case also would like the Arduino low power sample for solar powered ESP32. Regards

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Me too, looking forward for some examples with ESP32. BTW found a very easy flasher for ESP32 at Releases · esphome/esphome-flasher · GitHub

I’ve hated to leave you guys waiting. I have the sample written, and now I’m currently having it peer-reviewed to ensure it is worth copying. :smiley:

I expect to have a pointer for you guys by the end of the day. :+1:


Almost there guys. We hit a point of inflection during peer review, and we are having an internal discussion.

While this conversation is taking place, I’m running the sample I’ve created to better understand the power consumption characteristics.

We should have something for you soon.


Sorry for the delayed response, but I have worked through several iterations to be sure to provide the best possible advice.

If you’re looking to build a low-power solution, I would suggest using the Notecarrier-AL, which we’ve purpose-built for this use case, and which runs in our Airnote.

Using the Notecarrier-AL gives you FULL CONTROL of the circuitry running between the Notecard and the host MCU, which allows you to tailor the power solution to your project. Then from your sketch, you will request the Notecard to completely disable the host MCU, thus maximizing the potential of your battery.

In the example linked below, the host firmware requests for the Notecard to disable the host MCU for a specific period of time using the ATTN pin, wakeup and report sensor data, then request to be put back to sleep. In order to simulate being routed to the EN pin on a regulator, this example uses the EN pin on the Feather’s MCU.

Several options exist which allow the Notecard to wake up the host MCU when certain events occur (such as incoming messages from the Notehub). There is a nice guide on the developer site that explores these options.

To answer your question exactly as asked:

Each MCU manufacturer publishes its own way of putting its MCU into “deep sleep” mode, such as this for the ESP32. We recommend that you look to your host MCU’s manufacturer for guidance and examples.

Here is a great article written on the topic:

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