Electronics FAQ

What? Raspberry Pi running Motion Pie. USB Webcam is connected to it. A bash script pushes small snippets of videos (shot when motion is detected() to your phone. How? Signup for PushBullet  and install the android app on your phone (and chrome extension on your browser) Take a Raspberry Pi and connect a Raspberry Pi Camera or USB Webcam to it. I used a UVC USB Webcam. Format a SD Card on your computer and write the Motion Pie image to it. Here is how  to do it. Connect your Raspberry Pi to your home WiFi router using Ethernet cable. My house has CAT5 wire running through pipes concealed in the walls. Perform basic configuration on the Raspberry Pi using its web interface.  Administrator password. (Otherwise you wont be able to connect to it using SSH/PuTTY) Setting the timezone. Network setting - I used static IP address. Enable FTP write support. Video Device - Camera name or rotation etc. File storage: I used "network share" option to point back to...

What are we compiling for? I have a couple of very hackable routers that I have flashed with latest version of OpenWRT -Barrier Breaker 14.07: TP-LINK TL-MR3020 (Pocket Router with USB Port |  Install Instructions | Image: openwrt-ar71xx-generic-tl-mr3020-v1-squashfs-factory.bin  | I use this device to build my Weather Station ) TP-LINK TL-MR3040 (Just like MR3020 but has a built-in battery |  Install Instructions  | Image:  openwrt-ar71xx-generic-tl-mr3040-v1-squashfs-factory.bin ) Dragino MS14 ( OpenWRT wiki | Product Page | Firmware installation and instruction | Change Log |  Firmware Image ) All these routers have the AR9331 SoC in them which is MIPS and not MIPSel. MIPSel refers to a MIPS architecture using a little endian byte order. Since almost all MIPS microprocessors have the capability of operating with either little endian or big endian byte order, the term is used only for processors where little endian byte order has been...

The problem: I have a buggy 4G LTE router (a  ZTE MF29  used with  Airtel 4G  here in Pune, India) which hangs around thrice a week causing loss of connectivity until it is rebooted manually by toggling the power button on its back. I cannot get the 4G LTE router exchanged - I am stuck with it. And there hasn't been any firmware updates, neither does it have any option for rebooting using its webpage based management console. So I have to climb up to the small loft where I have kept my network equipment and manually toggle the power switch on the back side of the router. The problem is compounded by the fact that I have setup a wired LAN between 2 more apartments in my building complex. Three of us friends bought flats in this building together and we had the foresight to ask the builder to run lengths of CAT5e cables through the concealed wiring pipes between our houses. This allowed us to create our own LAN and have a common internet connection. Now when the G...

Quiz contest's are one of the most fun ways to learn things in a group. Throw in a buzzer system and you have sense of urgency, excitement and teamwork surging through the various teams. Couple of years ago (in 2006) - before Arduino or microcontrollers - me and Ranjit  assembled a parallel port based buzzer system. We had 5 buzzers for upto 5 teams - we used the 5 Status pins (nACK, Busy, Paper Out, Select and nError) of the parallel port to read the status of the switches. The project lasted us a long time - till the time they stopped equipping laptops with parallel ports! Some of the features of this system were: Use of bell switches as buzzers. the spring action, brings the switches back to off position. Use of microphone coaxial cables - these sturdy yet flexible cables are designed to be stepped upon and still last long! Use of RCA connector to attach and detach buzzers - essential because we were using coaxial cables Pull up resistors to make sure the status pins...