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 a 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 toolchain for build
st-link for flashing

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

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