Skip to main content

Posts

Showing posts from May, 2015

FLL EV3 Robot

This blog post is about our current EV3 robot we're planning to use in the 2023/2024 FLL competition. Some features: 2 large motors for steering. 2 medium motors for attachments.  2 colour sensors for picking up the white and black lines, also used for line squaring. 1 gyro sensor. To enable attachments to be changed as quickly as possible we're using gravity to keep the gears connected, i.e. you don't need to fasten anything to the robot. Every attachment has 2x 12 tooth double bevel gear (part 32270) which comes in contact with the 2x 20 tooth double bevel gears (part 32269) on the robot. The medium motors are horizontally aligned on the robots, but we use 12 tooth double bevel gears to convert that to vertical alignments. These in turn are connected to 20 tooth double bevel gears, and the attachments in turn connect to these 20 tooth double bevel gears with their 12 tooth double bevel gears.  The complete robot is modelled in Bricklink Studio 2 . You can download the rob

OpenWRT router connected to two networks

This post will explain how to set up your OpenWRT router to connect to two networks and configure it to route the traffic to the correct network. In this case we will connect both to a corporate network (i.e. enabling you to access the corporate network) and the internet (via an Internet Service Provider). Although most corporate networks allow you to access the internet they usually block specific ports (e.g. for Remote Desktop) and apply all sorts of weird and wonderful restrictions. I'm using an old Linksys WRT54GL with OpenWRT Backfire 10.03.1. Later OpenWRT releases can't run on the WRT54GL due to limited memory, but OpenWRT 10.03.1 is capable enough of doing this type of work. To access the corporate network I'm using the WAN port on the router (eth0.1), mapped to interface WAN. For access to the internet I'm running Wifi in client mode (wl0), mapped to interface WWAN. In principle it does not matter how you connect to the different networks - it could be

Install OpenWRT 14.09 on TP-Link MR3420 with Huawei E353 3G dongle

This post will describe how to install OpenWRT 14.09 on a TP-Link MR3420 router, plus configure it to use a Huawei E353 3G dongle to connect to the internet. First download the firmware, plus extra packages we'll need later. Store this on your computer: http://downloads.openwrt.org/barrier_breaker/14.07/ar71xx/generic/openwrt-ar71xx-generic-tl-mr3420-v1-squashfs-factory.bin http://downloads.openwrt.org/barrier_breaker/14.07/ar71xx/generic/packages/base/kmod-mii_3.10.49-1_ar71xx.ipk http://downloads.openwrt.org/barrier_breaker/14.07/ar71xx/generic/packages/base/kmod-usb-net_3.10.49-1_ar71xx.ipk http://downloads.openwrt.org/barrier_breaker/14.07/ar71xx/generic/packages/base/kmod-usb-net-cdc-ether_3.10.49-1_ar71xx.ipk http://downloads.openwrt.org/barrier_breaker/14.07/ar71xx/generic/packages/base/kmod-usb-net-rndis_3.10.49-1_ar71xx.ipk http://downloads.openwrt.org/barrier_breaker/14.07/ar71xx/generic/packages/base/libpthread_0.9.33.2-1_ar71xx.ipk http://downloads.openwrt.org/