Electronics FAQ

Here is how you would go about setting up Eclipse's M2M development environment on your Windows Computer & Raspberry Pi. This blog post can be considered as a simplified (and a little bit updated) version of " Run Mihini on an Open Hardware platform " specific to RPi/ArchLinux combination: Get your Raspberry Pi up and running: Get the latest ArchLinux SD card image for Raspberry Pi from here Write the image on to an SD card using either dd (if using Linux) or Win32 Disk Imager (if using Windows) Boot the Rasberry Pi using the newly created SD card. Make sure it is connected to your LAN (i.e. home WiFi Router) using a straight Ethernet cable. Your Windows PC should also be connected to the same LAN using WiFi or Ethernet. Login to your WiFi router's management web page and figure out the IP address that your router has assigned to your Raspberry Pi. In my case the Raspberry Pi's address was 10.10.10.23 Looking up RPi's IP address from the rout...

Are you developing a userspace application on Linux? Do you want it to spew out debug/log messages to a console? Do you want these messages to be colour coded, categorized by level and module? Do you want to print the name of the function which generates these messages? Do you want the ability to turn these messages on and off easily? If yes, then grab this code: debug_userspace.h: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 //debug_userspace.h ...

Chip on board. Itne paise mein itnaich milega.

I used the Vodafone K3770-Z 3G USB Modem with TP-LINK MR3020 pocket WiFi Router and it worked fine! Until it didn't. The red light kept flashing, the white light never came on. The device never associated with the network. AT commands to dial out returned "No Carrier". I left the router (and the 3G stick) on for 24 hrs for over a week. There were a few power cuts, and so the stick was on only 90% of the time. The 3G modem as we already know gets hot when in constant use and that heat probably caused the RF components to wear out fast. The RF frontend tuner probably drifted out of range or got damaged, although there were no signs of burns when I opened the thing up. Here are a few photos of its innards.

If you are running Linux as a guest virtual machine on a Windows host (or some other OS) using VirtualBox, you might have encountered the following error when you try to compile something on the Linux guest: make[2]: Warning: File `/media/sf_GitHub/misc/script_build/../../stack/lkm/ipstack.o' has modification time 0.51 s in the future This happens when you try to build inside a folder shared from Windows using the VirtualBox Guest Extensions. There is a minute but detectable delay between the moment when gcc tries to write the intermediate .o file from inside the Linux guest and when it is actually written to the hard disk outside on the Windows host. To get rid of the problem, just set the Linux guest's time 1 minute or so ahead of the time on Windows host.

While debugging a kernel module that we were developing, we wanted a kernel with some hacking options enabled, specially the  kmemleak  feature. Here is how we got that done. We were using Ubuntu i386 12.04.2 on a VirtualBox guest virtual machine running on a Windows 7 host. Make sure you have atleast 7GB of free space on your system. While creating the VM, I set my disk size (dynamically expanding) to 20GB. Also make sure you do this on the latest Long Term Support (LTS) version of the Ubuntu supported at the time. Install VirtualBox Guest editions if using a VM so that it clipboard sharing is enabled making it easier for you to copy and paste command from the Host OS to Guest OS. Update the system. This is essential as you need the very latest collection of userpace programs, kernel, and userspace-kernelspace libraries which are know to correctly work together at the time you try this. This is necessary becuase when you download the kernel sources, it will be of ...

A major quantity of electrical/electronic equipment imported into India have a Europlug. The Europlug fits poorly in many Indian style 3-pin sockets. Here is the analysis of the situation. Suggested solution involves using an appropriate converter. The irritating Europlug