programming chelahmy

If you search the Internet for ESP8266 you will get Arduino related results. It seems that the world see ESP8266 as a part of Arduino. This may change in the future. I prefer not to use Arduino for ESP8266 development because that approach was technically a work-a-round. Arduino IDE was designed for its own devices. I don't want to use an IDE which generally comes with unnecessary dependencies and constraints. I want to have the full control of the device that I'm working on. That's why I started my earlier ESP8266 developments with esp-open-sdk . I'm okay with the command line approach and a simple text editor. Now I want to utilize the real time operating system and explore its potentials. ESP8266 is powerful enough for RTOS. I searched the Internet for ESP8266 and RTOS, and I found many paradigms. ESP8266 is in a constant development. People were trying all sorts of approaches because in the beginning they were left alone . And now Espressif seems to take over

A MicroSD card can be directly connected to a 3.3v microcontroller without the need of any additional module. However, a cheap module such as shown in the picture above can be handy in terms of wiring and card replacement. Yet, if you get the module from China then you are on your own, you have to figure it out yourself how the module works. The module above needs 5v VCC to operate. The 5v is needed by the 3.3v LM1117 regulator to power the MicroSD card and the 74125 bus buffer (the 14-pin IC in the module above). Hence, the bus buffer is operating at 3.3v. The VCC is connected directly to the input of the regulator and no where else. Thus, the VCC is solely meant for the regulator. The right-side SPI bus (CS, SCK, MOSI & MISO) is connected directly to the 3.3v bus buffer. No line in the SPI bus that is connected to the VCC. Thus, the SPI bus does not follow VCC. The buffer is 5v tolerant so the right-side SPI connection can be driven at either 3.3v or 5v. Hence, the SPI ca