I'm building a custom 3G router for all my Internet needs. It's going to be portable, with battery backup enough to get through about half a day with more or less active 3G usage, able to be charged using 5V, so any USB socket would do if I needed network access and it was discharged... As well as any barrel plug charger from 5V to 12V - I could unplug someone's router to charge mine =D
It'll be powered by Black Swift board, an SD-card sized AR9331 development board, running OpenWRT. It's going to have some additional features, such as support of many kinds of USB devices, file, printing and music servers, some additional services, such as transparent VPN connection and ad-blocking proxy and, generally, whatever I manage to code in and connect to the board.
Some technical specs:
- Black Swift board - AR9331 board with DDR2 memory and built-in WiFi, as well as 2 Ethernet ports available on breakout connectors.
- Li-ion battery, 2x 18650 in a custom holder. Configuration: 1s2p, 3.7V, 4000mAh
- Built-in step-down DC-DC to power it from all kinds of voltages, such as 9 or 12 volts. I'll use 5.5x2.5 socket for that, as it's one of the most popular barrel plug standarts.
- USB 3G modem (for now, just a usual dongle, later I plan on getting a miniPCI-E card, I guess they're more power-efficient and otherwise optimised.)
- USB hub - 4 ports for various devices, could be extended to 7 ports later if necessary
- USB-UART connected to the BSB UART for easy debugging - just take the cable, plug it in your laptop and see the boot logs
- Arduino to offload some pin-wiggling and power management tasks
- Possibly, Bluetooth for sync,audio and stuff =)
- IR receiver for control
- RGB LED for diagnostics and status indication
- DTMF generator with a speaker as original approach to diagnostics =)
- Available USB ports for both charging and connecting devices
- DS1307 RTC with battery backup - I have plenty of these ICs, would have been a shame not to stuff it in =)
- LED lamp for searching, reading and hacking.
- ...more things already being planned =)
I'm gonna fit it all in a small case you can see on the picture. It's a case which probably was a case for an old USSR transformer PSU for some piece of tech, could even have been a radio =) Anyway, this is a nice case, as it allows me to make a prototype and change it on the go, yet keep it relatively small and portable. I like how this case limits me yet fuels my imagination on how I can do things more efficiently.
Current state of the project: