Browsing All posts tagged under »stm32«

STM32 Nucleo: access SD cards with C standard library

July 3, 2016


The ST Nucleo is an Arduino-like board with an STM32 as the microcontroller, and many Arduino shields can be mounted on it. I recently played with an Ethernet shield for the network connection, but since the shield also contains a microSD card slot, I wanted to access the SD card to read/write files. I’d like to […]

Simple time synchronization for the Internet of Things

February 18, 2016


While adding HTTPS capabilities to my STM32 Nucleo board, I needed to solve the problem of current time. This is because TLS needs to check certificate expiration date, so we need a sufficiently accurate estimation of time. So I tried to understand what could I do to ask a network server about the time. I […]

HTTPS client on STM32 Nucleo-F411RE

February 4, 2016


One of my goal of the past months was to use an STM32 Nucleo board to get a webpage through HTTPS, using an Ethernet shield for TCP/IP stack. I was close last time, but I discovered that my Nucleo-F103RB did not have enough RAM. Now I have my hands on a Nucleo-F411RE that has 128KiB of RAM […]

STM32 NUCLEO-F103RB has low resources for TLS 1.2

January 10, 2016


It’s been months since I started playing with a STM32 Nucleo + Ethernet shield. One of the objectives that I chase is to build a device for the Internet of Things that implement reasonably secure communications. In an effort to avoid reinventing the wheel (or at least to not reinvent too many wheels) I wanted to see if […]

DNS client on STM32 Nucleo and W5100

December 13, 2015


I am still working on a device consisting of STM32 Nucleo F103RB with a W5100 Ethernet shield. This time I included a DNS client, so that the device can connect to a server by knowing its name. The name resolving can be invoked by using the POSIX functions getaddrinfo and gethostbyname. DNS queries can have different […]

DHCP client on STM32 Nucleo and W5100

December 7, 2015


I am still working on a device consisting of STM32 Nucleo F103RB with a W5100 Ethernet shield. This time I included a DHCP client, so that when the device is attached to a network, it will ask for an IP address instead of being statically allocated. The DHCP protocol follows the RFC 2131 and RFC 2132, and […]

Update on POSIX socket library for W5100: client and server for TCP or UDP

November 22, 2015


I am writing a library that implements POSIX sockets, also called Berkeley sockets, for my ST Nucleo+Ethernet shield setup. The functionality that is currently in place, as for the source code on GitHub, allows for TCP client/server connections and UDP client/server communication using Wiznet W5100 chip resources. The interface is not complete, but what’s in place is taken as literally as I […]