Is there any interest in STM32F107 dev board with onboard Ethernet and PoE? - Page 1
Forum section: electronics / general

author: technix
author_rank: Super Contributor
timestamp: November 14, 2016, 10:43:59 am
content: Back then I bought a few STM32F107 (ARM Cortex-M3 MCU with built-in Fast Ethernet MAC) and RTL8201 (Fast Ethernet PHY, a fairly old and classic design) with the intention of building a dev board with built-in Ethernet. (a missed opportunity for Arduino Due sadly.) Is there anyone also interested in such a board?

author: Scrts
author_rank: Frequent Contributor
timestamp: November 14, 2016, 04:13:42 pm
content: I bet it would. I am routing ethernet cable across the house with an idea that I will use PoE with most of the devices.The other thing is: there has to be software support/examples backing up your board.

author: ChristopherN
author_rank: Unknown
timestamp: November 14, 2016, 04:25:22 pm
content: Sounds interesting, which PoE version would you use?A pure "passive" PoE port is not as interesting as a real PoE port. It would be cool if the board could fit in a small wall-insert hosing such as this one:

author: technix
author_rank: Super Contributor
timestamp: November 14, 2016, 04:57:09 pm
content: Quote from: Scrts on November 14, 2016, 04:13:42 pmI already have a semi-working Arduino-compatible core for the STM32F1 platform, so that can be a starting point, although there is currently no network stack for that. The other thing I still need to figure out is onboard debug probe (probably based on CMSIS-DAP with full 4-wire or 5-wire JTAG) which should be implemented on a STM32F103CB.By the way, I have Ethernet cables already set up to each and every switch box in my apartment. They are left dangling so far, but if I want to I can quickly set up PoE-compatible IP-controlled dimmers and switches, and I already have a managed switch (for VLAN) and a 24/7 home server to be used as the gateway.

author: technix
author_rank: Super Contributor
timestamp: November 14, 2016, 05:01:27 pm
content: Quote from: ChristopherN on November 14, 2016, 04:25:22 pmI have not decided on which revision I will use yet. I don't want to wind my own switching transformer (confused AF) so maybe I will stick to the small PoE chip from TI and use a ready-made 48V to 5V isolated power module.This is going to deviate from my original idea. My original idea was a Arduino-compatible form factor (2 USB ports, as well as the Ethernet PoE port in place of the usual DC barrel jack) with a built-in CMSIS-DAP debug probe. If it is designed to go into this size, the onboard debug probe have to be removed, and it will be a bit difficult for my current component choice which uses the 100-pin variant instead of the 64-pin variant.

author: ChristopherN
author_rank: Unknown
timestamp: November 14, 2016, 07:19:36 pm
content: Ok, that could be handy as well.Could you add some mounting holes that take M3 screws? Some Arduino boards only have M2.5 mounting holes, that's annoying.Please let me know if you need any support for this project, I would consider buying a few boards.

author: technix
author_rank: Super Contributor
timestamp: November 14, 2016, 08:54:31 pm
content: Quote from: ChristopherN on November 14, 2016, 07:19:36 pmIt is standard Arduino Mega size with standard M3 holes, but there is a few less rows of usable pins than Mega as the chip don't have that many I/O pins after pins being used. I chose to use some fairly pin-consuming interfaces for better reliability and speed:* 5-wire JTAG instead of SWD for debug probe,* Full Fast Ethernet MII* One of the three SPI buses occupied by MAC EEPROM (so I don't have to buy OUI and have a solid place to store network configurations)* Two crystals with backup battery for RTC