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Topic: ESP8266 (Read 92990 times) previous topic - next topic

westfw

Quote
I have the following set up between a nano and the ESP-8266:

VCC-------->+3.3v
If that's ESP8266 VCC to Nano 3.3V, be aware that the nano 3.3V regulator is not powerful enough to power an ESP8266.

If that's Nano VCC (5V!) to ESP8266 3.3V, that's just wrong and has probably fried your ESP.


JonMiles

If that's ESP8266 VCC to Nano 3.3V, be aware that the nano 3.3V regulator is not powerful enough to power an ESP8266.

If that's Nano VCC (5V!) to ESP8266 3.3V, that's just wrong and has probably fried your ESP.


No, i had heard of those issues before. It id 3.3v external power. Not power from the nano. I have double checked and it is supplying 3.3v. We 3.28v but close enough.

boelle

Hi

can anyone help me with a "small" project?

i want to create an thermostat for an electrical heating control.

i found almost what i wanted in this code here: https://github.com/mharizanov/ESP8266_Relay_Board

the only thing missing is a push button that allows to override the normal target temp to something else for a set period of time


its intended for a flat where an autism person lives along with the care taking staff


the last group (staff) has a very bad habbit of messing with the panels and it tages ages to set the dials etc as the other flats give of heat too

my plan was using the firmware above and then if the staff should feel cold they can push a button to get extra heat for say 15 mins

jerryk1234

Hello,

   I'm working on a little IOT project, nothing complicated.  I settled on the arduino system for my nodemcu cards because it was just more stable than trying to program them with Lua.  I am minimally familiar with C++, but have some years of professional-level embedded programming experience in C.

  Does anybody know how to get access to the sub-os world of the processor?  I'm specifically talking about processor registers and physical memory.  Even more specifically, at the moment, the stack pointer.

  I'd like to apply a few simple tests to the stack pointer to help with reliability.  I understand that the esp has
a small 4K stack.  C, in general, is a stack-intensive language.  4K seems like enough for a little IOT project, but...

  At the top of the main loop, the stack pointer should always be the same value.  If it changes, it means that
  somewhere, a push was not matched by a pop, or a call not matched by a return.

  I'd like to set some words near the end of the stack to a magic number.  If that number changes, we're close to blowing the stack.

  The ideal thing would be a way to embed snippets of assembly language....




westfw

(This probably deserves to be a new topic.)


Quote
The ideal thing would be a way to embed snippets of assembly language....
esp8266 uses gcc, so it has the same sort of inline assembly language capabilities as all the other gcc variants.
The core CPU is a  Tensilica Xtensa lx106 MCU, which you can find documentation for.

Note that the ESP8266 is a multi-tasking system, with the arduino-like loop() being one of the tasks.  I would not be surprised if there were multiple stacks...

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