DIY Power Measurement Board

When I review media player or development boards, I’m often asked about power consumption figures. One way to measure power consumption is to use a Kill-a-Watt, but for low power devices it’s not always accurate enough, and it also includes the heat dissipation from the power adapter, which may or may not be useful depending on what you want to measure. For USB powered devices or boards, an easy way to measure power consumption is to use CHARGER Doctor, a small $5 USB dongle that displays both voltage and current alternatively. Unfortunately, most products I’ve received lately use barrel type connectors, so this little tool has not been as useful as I hoped. The only solution is then to measure voltage and current with a multimeter. Voltage is measured in parallel, so you just need to point the multimeter’s leads where you want to perform the measurements. However, the current […]

How to Use an Android TV Box as a Wi-Fi Access Point

Today, I’ve come across another potential use case for Android TV boxes with Wi-Fi and Ethernet. Let’s say you are in a room with Ethernet, but there’s no Wi-Fi signal or the signal is too weak, and want to use your smartphone to connect to the Internet via Wi-Fi. If you don’t have one of these small (openWRT) Wi-Fi router with you, but instead brought an Android mini PC, you can configure the “Portable Hotspot” function to transform it into a secure Wi-Fi access point. Assuming you’ve connect an Ethernet cable, and powered the device, first make sure Ethernet is enabled\, and Wi-Fi is disabled in the Settings menu. To click on Settings->More.. in the Wireless & Networks section, and select “Tethering & portable hotspot” or simply “Portable hotspot” depending on your firmware. In the next menu, click on Portable Wi-Fi hotspot to enabled it, then “Set up Wi-Fi Hospot” […]

Easy and Safe Way to Try Linux on Popular Rockchip RK3188 mini PCs

Until recently, installing Linux on Rockchip R3188 based TV boxes or HDMI TV dongles meant you had to flash one or more binaries to your device using various type of tools for Linux or Windows. But thanks to various members of the community, it’s now as easy as flashing an image for the Raspberry Pi, as long as you own Minix Neo X7, PQ Labs iStick A350-SSD, Radxa Rock development board, or Rikomagic MK802IV (AP6210 or 8188EU Wi-Fi module versions) thanks to images provided by Ian Morrison on G+ mini PC community that can be booted from a (micro) SD card, which the added advantage that it won’t mess with your Android installation. You can do it whether you use a Windows or Linux PC, and it should also be possible on Mac OS X, but I don’t know the commands. Here are the steps to follow for MINIX NEO […]

How to Try Android L Developer Preview in Ubuntu 14.04

As mentioned yesterday, Android L Developer Preview was about to be released, and this is now done with images for Nexus 5 “Hammerhead” and Nexus 7 “razor” available right now. However, if you don’t have either of these devices, or you’d rather not install a beta version on the phone you use everyday, you can still give a try in the SDK emulator. I’ve tried Android L myself in Ubuntu 14.04. Here’s what you have to do: Install Android Studio IDE in Ubuntu, and Create a new Project  or open an existing project (Android Studio Version is now 0.61) Click on Tools->Android->SDK Manager in the top menu, and select the Android L (API 20, L Preview) packages as shown below, and click on “Install xx Packages” button. Accept the license as required, and click Install. This step can take countless hours… Now we’ll need to create a Virtual Device for […]

Low Power Mode (Suspend to RAM) in uCLinux for Freescale Kinetis K70 MCU

All ARM based micro-controllers and processors implement multiple power mode in order to save optimize power usage depending on the tasks. However, I’ve been told by some hobbyists/developers/makers that low power modes are not always implemented in Linux, especially for low cost systems either because of hardware limitations or the software is not implemented. EmCraft Systems has just released their latest embedded (uC-) Linux distributions for the MCU boards, and one of the features now available is “suspend to RAM” for their K70 SoM development kit, based on Freescale Kinetis K70 Cortex M4 MCU, which consume just around 600 to 700 uA @ 3.3V (2 to 2.3 mW) in this low power mode. They have connected a multimeter to measure the current drawn at different power modes. If you want to know all the details, you should probably read the company’s article on “Linux Low-Power Mode on Kinetis“, but I’ll […]

How to Upgrade Firmware for Rockchip RK3066, RK3188, RK3328, RK3288, RK3399 Devices with the Command Line in Linux

Previously I wrote an article entitled “How to Flash Rockchip RK3066 / RK3188 Firmware in Linux” explaining how to use a graphical tool called RkFlashKit to upgrade firmware on Rockchip devices using a Linux computer. This tool had some limitations, and it would just have a subset of features of RkAndroidTool (Windows), and it was not possible to flash “update.img” type of firmware which are often provided and flashed with RkBatchTool in Windows. Luckily there’s now a command line tool called upgrade_tool that allows you to flash the “update.img” firmware files directly from Linux. I’ve already shown how to use it with Radxa Rock, but it’s buried with other instructions, so I’ve decided to make a separate post. This has been tested in Ubuntu 14.04 with Radxa Rock (RK3188) and Measy U2C (RK3066). Ready? Let’s start by downloading and extracting upgrade_tool. You may want to add the installation path to […]

Ubuntu 14.04 and Slitaz on Radxa Rock

Various Android and Linux images are available on Radxa Rock download page, but if you’d like to get newer images or other options, two developers have provided binaries and posted instructions to get Ubuntu 14.04 and Slitaz operating systems, the later currently booting with Linux kernel 3.10. Naoki FUKAUMI has published a miniroot how-to install a Ubuntu 14.04 Core (minimal headless installation) on Radxa Rock and Radxa Rock Lite. Installation should be relatively easy as he provide the update.img for both board so your can use the usual method in Windows (RkBatchTool) or upgrade_tool in Linux. If you don’t have serial console, you’ll have need to flash the parameter file requiring RkAndroidTool in Windows, and the same upgrade_tool in Linux. If once the installation and configuration is complete, you want a desktop environment,you can always run “apt-get install lubuntu-desktop” to install LXDE. SliTaz is a lightweight Linux distribution. I previously […]

How to Boot a Headless Linux Image on Amlogic S802 TV Boxes (Tronsmart Vega S89 Elite)

As some of you already know, I’ve been playing around with Tronsmart Vega S89 Elite, an Android TV Box powered by Amlogic S802 quad-core ARM Cortex A9r4 processor at 2 GHz. Today, I’ll show how to boot a headless Linux image on any Amlogic-based S802 TV Box from the network. The instructions can mainly be used as a starting point for developers, as it requires access to a serial terminal via  UART, but if you’ve never done it before, the instructions should be easy enough to follow. Everything is loaded from the network, the kernel (via boot.img) is loaded via TFTP, and the rootfs (Linaro ALIP image) is mounted via NFS, so it’s nearly impossible to brick your device using the method provided. Linaro ALIP rootfs comes with LXDE, but at this stage, the desktop environment is not showing, even though my HDMI TV is properly detected by the drivers. […]

EmbeddedTS embedded systems design