- STM32F407 with 1GB of flash and 128KB + 64KB CCM of RAM, running at 168MHz.
- LAN8720A Ethernet PHY with 10/100Mbit.
- Two step power supply with 12V to 3V8 switching and 3V8 to 3V3 LDO.
- Battery for RTC CR2032. STM32F407 has on-board RTC.
- 10 analog (balanced) inputs for PIR, smoke, ...
- 4G SIM7600x module
- Radio module for RFM69HCW, or alternatively RFM95.
- 128KB SPI FRAM.
- RS485 for wired connections.
- 2 relays for sirens.
- 1 tamper zone for enclosure.
- Micro USB port.
- ST-LINK V2 port.
- 3 LEDs.
FRAM size has doubled for the reason to store some larger data needed conveniently. First half (64KB) is used as before to keep 4096 log entries for gateway logger. Second half will be available to several new functionalities I plan to add to gateway software. I was also tmepted to add a uSD card, but it is easier to store data on synchronous SPI FRAM, then to access uSD with file system that can be damaged or not present. Not to speak about wiring.
Also there is now a shotky diode, to add polarity protection to RTC battery.