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Showing posts from May, 2013

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 Attitude Adjustment 12.09

My TP-Link MR3420 router was running OpenWRT Backfire 10.03.1 for quite some time now. OpenWRT has released a new version recently: Attitude Adjustment 12.09, so I've decided to upgrade. When choosing an image file to download, you have 4 different choices. First of all you can choose between a factory or upgrade image, and for each one you can choose between squashfs and jffs2 - the filesystem used, either making use of a read-only squashfs with a overlay filesystem (jffs2) - i.e. overwriting read-only files, or completely jffs2. I've decided to go for the upgrade image, but in the end (and I'm only realising this now) probably chose the wrong filesystem because my router won't boot after the upgrade. The SYS LED keep blinking but no wired and wireless access. I've tried to do the factory reset but no luck. (By the way - I recommend to use the squashfs image. One of the benefits of squashfs is that you have a failsafe option available when things go wrong - by