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Postby nickking » Wed Mar 06, 2019 10:23 pm

hello experts

I am new to ESP32 nodeMCU we are thinking of using this ESP32 i have some question please answer

1. Can i use freeRTOS on this ESP32 nodeMCU to do a specific functionality ?
2. Is there any SDK that has all drivers and freeRTOS for the ESP32 nodemcu to work on if so please provide me the link to download SDK ?
3. Is there any IDE tool to code the C,C++ application and push our application to the ESP32 ?
4. how much flash memory does ESP32 nodeMCU have both internal and external ?
5. how much RAM does ESP32 nodeMCU have both internal and external ?
6. Is it possible to update the application remotely via wifi ?


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Re: freeRTOS

Postby ESP_Angus » Thu Mar 07, 2019 2:18 am

Hi nickking,

"nodemcu esp32" is a development board, so for exact answers you'll have to ask the development board manufacturer. But the development board will use an ESP32 chip, so for the chip part we can answer the questions.

For the software questions, the FreeRTOS-based SDK you want is ESP-IDF. Docs which answer the other questions are here:

For hardware questions about the ESP32 chip, check out the ESP32 datasheet and Technical Reference Manual (TRM) downloadable from here:

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Re: freeRTOS

Postby nickking » Thu Mar 07, 2019 4:49 pm


I have another question in my mind since ESP32 nodemcu does not have any internal flash memory
  • Does the CPU directly run the application code/instruction from external flash or does it load the application instructions part by part into the RAM and then execute from RAM

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Re: freeRTOS

Postby ESP_Sprite » Fri Mar 08, 2019 8:28 am

The answer would be ... errm, I guess 'both'? From a programmers point of view, some specific code that also needs to be able to run when flash is offline is loaded from flash into IRAM at startup. The rest of the code is executed directly from flash.

However, flash itself is pretty slow, so internally, we have 64K of cache memory. When a routine runs, it automatically gets loaded into this cache and when it runs again, it doesn't have to be loaded again and runs much quicker. So while to a programmer, it still looks as if we're executing the code directly from flash, it's actually a lot faster than that.

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