EEPROM for ESP8266
This article describes a small EEPROM emulation library that I wrote for ESP8266. It implements a very simple EEPROM emulation scheme that allows storing 16bit values. Each such 16bit value is found by its 16bit index.
This article describes a small EEPROM emulation library that I wrote for ESP8266. It implements a very simple EEPROM emulation scheme that allows storing 16bit values. Each such 16bit value is found by its 16bit index.
Not long ago, to little fanfare, Espressif (the makers of ESP8266) released gdbstub – a library that allows use of gdb on ESP8266. It works with both non-OS and RTOS SDKs, and works over UART, not JTAG. You get 1 breakpoint for RAM and 1 breakpoint for FLASH. Is this awesome, or what!? Authorship is […]
I wanted to know which memory allocation scheme (heap_1.c, heap_2.c, heap_3.c, heap_4.c or heap_5.c) was used in the ESP8266 RTOS SDK. This is not mentioned anywhere in the docs (I’ve looked as of 1/12/16). What to do? Let’s just take a look at what is compiled in then.
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$ cd /path/to/RTOSSDK/lib $ xtensa-lx106-elf-nm libfreertos.a | grep -50 "T pvPortMalloc" |
Actually, this works even with a […]
Since update from version 1.2 to 1.3 of Espressif’s RTOS SDK, if you try to compile anything targeting a 512kB flash device you get this message:
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`.irom0.text' will not fit in region `irom0_0_seg' |
In this post I will show you how to organize and compile a project to using the RTOS SDK and how to solve the above problem. This post […]
Espressif SDK provides a function os_printf() for printing to the debug uart. However, when used out of the box it prints garbage. What gives? Consider a default project with the following in user_main.c.
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void user_init(void) { os_printf("hello world\n"); } |
Compile, run, what do you see? That’s right – garbage. Well, it’s not really garbage, it’s actually outputting “hello world” at […]
They say that laziness is the mother of progress. It certainly was in my case. I am currently residing in Indonesia, where the outside lighting of one’s house is somewhat of a security practice, and it so happened that it became my job to ensure that these lights went on every evening, and equally importantly, […]
The AT firmware is the default firmware for ESP8266 and provides AT style commands for actions such as join access point and send tcp packet. It is distributed in binary form by Espressif, but it can also be built from source (binary blobby as it may be). Typically one can find a new version of […]
Here is my method of mounting esp8266‘s, specifically ESP-03 on a breadboard without the use of a breakout board. Details inside.
Here are some obvious and not-so-obvious pitfalls you may encounter while trying to communicate with an ESP-03 over UART. We will be using a USB-Serial device to connect directly to the ESP.