A complete HTTP device dashboard with:
- User authentication
- Real-time device data graph
- Coninfiguration display and update
- MQTT communication with a remote MQTT server
Implements SNTP time synchronisation
No dependencies: no HAL, no CMSIS, no RTOS
Hand-written mcu.h header based on the datasheet
Interrupt-driven Ethernet driver
Blue LED blinky, based on SysTick interrupt
User button handler, turns off/on green LED, based on EXTI, interrupt-driven
HardFault handler that blinks red LED
Debug log on UART3 (st-link)

Requirements

GNU make
ARM GCC
stlink for flashing

The Makefile defaults to using Docker for the compiler, so you don't actually need to install it if you are using a Linux/Mac workstation. If you are not, or you want to run your local ARM compiler, just append DOCKER= to the make commands depicted below to call the compiler directly; it must be in your executable path.

In any case, the links above will send you to tutorials on how to install each of those tools in your workstation for Linux, Mac, and Windows.

Usage

Plugin your Nucleo board into USB, and attach an Ethernet cable. To build and flash:

$ make clean flash

To see debug log, use any serial monitor program like picocom at 115200 bps and configure it to insert carriage returns after line feeds:

$ picocom /dev/ttyACM0 -i -b 115200 --imap=lfcrlf

There is also a detailed tutorial on this example

Benchmark

A quick comparison is made with several other implementations. Note: IP in the table below is the IP address printed on the console after boot. The benchmark command is the same: siege -c 5 -t 5s http://IP

	Zephyr	LWIP sockets	LWIP raw	MIP
Requests per second	3	16	286	1080
Firmware size	117k (*)	160k	114k	28k

Zephyr: uses Zehypr's RTOS and TCP stack, with Mongoose library on top, source code. (*) By default, Zephyr example is TLS-enabled. To compare sizes, a TLS-disabled build was done by disabling TLS in prj.conf and CMakeLists.txt
LWIP sockets: uses FreeRTOS and LWIP with sockets support, with Mongoose library on top, source code. built with #define MG in Core/main.c
LWIP raw: uses FreeRTOS and LWIP without sockets, LWIP's httpd server, source code. built with #define MG line commented out in Core/main.c
MIP: this repository