Wednesday, July 8, 2020
There are two changes to final version gateway board for 2.0.4. The PCB remain the same as well as all functionality, but I decided to opt for easier software changes in future.
What I mean is that I changed the MCU on the board from STM32F407 to SMT32F437. It has 64KB more RAM, and hardware accelerated cryptographic unit allowing better support for TLS. F437 allows also a higher nominal frequency, but for now I did not use this option, and left it on 168MHz. But it can come with new firmware if needed.
Second change is to switch to LAN7842A, an updated version of previously used LAN7820A. It has some new functionality which include WOL and Cable sense, which will not be need. But it has also lower power consumption and HP Auto-MDIX support. Basically LAN7842A is recommended for any new design.
On the software part, I've been pretty busy with new version. Porting many of the features of 1.7 gateway into 2.0, and I'm quite happy with it so far. My intention is to create gateway that will not need any other resources to function.
For example web interface use font awesome for icons, meaning you need connection to internet to see them, as this font has hundreds of kB. But thanks to fontello I managed to create subset of icons that has less then 10kB, witch perfectly fits into 1MB of flash available on MCU. So far, only remote thing that is needed is a SMTP server, in case you wish that gateway should also send email notifications.