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How To Connect your ESP32 to the Azure IoT Cloud over REST

How to connect ESP32 to the Azure IoT Cloud

In the last few years all big IT companies have discovered the Internet-of-Things field in one way or the other. Apple and Google have offerings for home automation, Google, Amazon and Microsoft offer services to connect IoT devices to the cloud. For one of our projects we wanted to take a look at Microsofts Azure IoT Hub solution. Microsoft offers comprehensive libraries to connect the ESP8266 to the Azure cloud. But what about the ESP32? In this post we’ll describe how to create a shared access token for the Azure cloud. We’ll further cover how to use this token to send a minimalistic request with the ESP32 to the Azure IoT hub.

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Max deep sleep for ESP8266

max deep sleep for ESP8266

In light of our recent power-consumption related posts 1 & 2 it seemed logical to ask ourselves about max deep sleep for ESP8266. Yet, it took a comment from a curious reader to set things in motion. I replied

…the maximum value for a 32-bit unsigned integer is 4294967295 or 0xffffffff. Hence, the max deep sleep interval appears to be ~71 minutes.

You can’t argue with that first statement but the second is a bit in the air without clear evidence. My co-founder Dani quite rightly then asked “are you sure, didn’t they change that recently?” (“they” being Espressif and/or the Arduino devs).

So then, what is the current max deep sleep for ESP8266 i.e. the maximum duration the ESP8266 can sleep deeply – and still wake up afterwards.

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5 Hacks to Prolong your ESPaper’s Battery Run-Time

In the last post I showed you how you can use cheap hardware to get a reasonable good power consumption test rig. In this post we are going to use this tool to improve the runtime of the ESPaper significantly. The short trial and error cycle possible with this tool will let us validate several ideas for improvement in only very little time. Continue reading 5 Hacks to Prolong your ESPaper’s Battery Run-Time

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ESP8266: Monitoring Power Consumption

In this post I’m going to show you how you can monitor the power consumption of your battery driven (ESP8266/ ESP32) device. Measuring the power consumption over a full activity/ sleep cycle is the precondition to optimize your code for a longer battery runtime. Only with a reliable tool you can decide which code changes lead to less consumption. In a later post we’ll look at some tweaks we can apply to the code to get a few more days out of the battery. Continue reading ESP8266: Monitoring Power Consumption