My setup

As promised to Dan, here is picture of my current setup.You can see mainboard(GW) with attached Wiz820io on it. Then GSM modem on right side. 868MHz antenna connector on top. Cables from PIR, smoke and GBS sensors in the middle.Lead Acid Rechargeable Battery 12V, 7.2Ah in bottom left corner and Meanwell switching power supply PSC-60-C. All mounted in metal box enclosure with tamper switch. As I work on new version now and not changing the software, it shows uptime "79d, 23:57:40".

Remote (door entry) units are connected also by wire cables (RS485 protocol) and there is already short video, how they work.

Web interface - home

Here on the right side is the home page of my security screen. There is not to much to set in terms of system functionality. There is system time, which is NTP synchronized on startup or whenever you hit the "Get NTP time" button (Connection to Internet is needed :). There are also information about the last system start up time and calculated uptime. Then information about power supply and battery state. Another section is about radio and GSM module statuses. Rather self-explaining I guess.

More important are the last three buttons. Starting from "Reset to default" that will wipe all configuration that is kept in the system RAM and replace it with "factory default". You would do it only in case you really want to start from beginning. The "factory default" must be confirmed by pressing any "Save all" button, so the changes are just loaded into RAM but not stored into EEPROM. You can go and take the last stored configuration in EEPROM by "Load last" button. "Load last" can also be used when you change temporarily any configuration in RAM for test cases. Just remember that in case of power loss the system stores current configuration form RAM to EEPROM just before the main backup battery is depleted.

Power supply

In last post I have mention the power supply is too strong. By checking the documentation again I can say it way to strong, 60W. Originally I have designed my own power supply with transformer, rectifier and some switchers to deliver 13,8V for battery and 5V for GSM. Together with some led signalizing the status of mains and battery. But later I have considered it rather inefficient for 24/7 running.

Developing a true switching power unit is rather expensive, beside I have no previous experience, and I'm just a hobbyist. And my favourite producer of power supplies had a nice choice of 13,8V units. I have chose PSC-60-C, the one with enclosure. It has two outputs, one for battery charging and one to power for main board. It has also open collector outputs for signals when the AC is off, or the battery is reaching low level(11V). Then it also cuts of the battery when it reaches 10,5V. Just everything I wanted and it has 84% efficiency. Also it looks nice and shiny in the box :)