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Showing posts from August, 2020

PC Logger: AutoIt3 script for PC activity monitoring

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Due to COVID-19, the kids had to do online learning for a couple of months. Unfortunately, they were constantly tempted to play games or watch YouTube during class time. Sometimes they became so immersed that they missed lessons, or forget to complete assigned tasks. I tried various solutions, such as parental control software, or lock down the router. None of them worked for me. There were just too many things to configure. Furthermore, some potential avenues for distraction (eg. YouTube) might sometimes be necessary for schoolwork (eg. YouTube being used for information or research by the teacher). The solution I eventually settled upon turned out to be quite simple. I hacked together an AutoIt script that logs details about the active window (title and executable) to a Google form periodically. By looking at the logs from time-to-time, it gives me a pretty good picture of what they have been doing on their computers, and have a chat with them when things get out-of-hand. Github repo

ESPCLOCK3, Runtime Upate

I started running the final version of ESPCLOCK3 on 22 May at 11:10pm on 4 x Ikea's LADDA AA 2450mAH rechargeables.  The clock ran flawlessly until 19 Aug 9:10am. So total runtime was just a few days shy of the calculated 4-month duration. The batteries were all depleted and measuring ~1V each. The clock was mounted in front of my desk, and it stayed accurate to the second throughout the entire time. The voltage level during the end of battery life seems to bounce around the 2.8V threshold level. So I will make some minor code change to stop the clock until input voltage level rises above some upper threshold level eg. 3.0V. I plan to run it for another test cycle. This test cycle should allow me to test clock adjustment for daylight saving.

DIY Roomba Virtual Wall, Part 5

After using the DIY Roomba Virtual Walls for a week now, I found something interesting that is rarely mentioned by the folks who have made this. The only mention I could find is from this blog post : "After examining the original virtual wall, with a webcam, I was able to see that it emits infrared light from its top round transparent ring and from a small hole above the switches. The light coming from the top ring prevents the robot from colliding with the virtual wall , if it comes from its sides or from behind. The front hole emits light as a beam. This beam of light is directional and stops at the nearest obstacle, probably a real wall, preventing the robot from crossing it to the other side." Indeed, when using the DIY version, the first thing I noticed is that the unit has to be strategically placed because the Roomba will knock into it more often than expected.  So a more robust DIY version will need to have another IR LED pointing at some kind of conical reflector mo

DIY Roomba Virtual Wall, Part 4

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So I went ahead and made another Roomba Virtual Wall. Everything else is pretty much the same as before , except I made each mounting layer one single ring, instead of 2 separate pieces. The single-piece design makes them easier to align and attach, at the expense of slightly longer print time and more filament used. When soldering the proto-board, I tried moving the 3 resistors to the bottom of the board. Bad move. It was too crowded. In the end, I moved 2 of them back to the top. I found that the IR LED that I used for this unit is actually the one I salvaged from the broken Roomba Virtual Wall because it has a very narrow degree of projection (2 ~ 3° at most). I thought the first unit had it. What happened was, I was testing out the IR LED from the virtual wall and the old TV remote on the breadboard, and somehow got them mixed up. So I thought the first unit was using the IR LED from the broken virtual wall, but actually it had the TV remote IR LED, which makes sense now, because i

DIY Roomba Virtual Wall, Part 3

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I created an enclosure for the ATtiny85-based Roomba virtual wall prototype board using FreeCAD . A couple of design goals: The LED is positioned about 7cm from ground level. The 3 x AA battery holder is 3D-printed, completed by battery clips salvaged from old toys (or readily available online ). The parts are designed to print with as little support as possible, and attached together using superglue and screws. I printed the parts using 0.8mm nozzle to save time, so they look a little rough. It takes about 7 hours to print all the parts on my Creality Ender 3. Nine M2.5 screws are required, one for the battery cover, eight for holding the body together. Superglue can be used for the latter, but I like the option to easily take the body apart for repair. Here is the battery box with battery clips inserted: JST male connector wire soldered at the back: Mounting clips attached with superglue. When working with superglue, move the parts in position and hold down with pressure for 60 secon

DIY Roomba Virtual Wall, Part 2

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Following on the success of the test circuit , I added a status LED and a pushbutton to the breadboard.  A summary of the connections: IR LED connected to pin 3 (PB4) of the ATtiny85 (100ohm current- limiting resistor). Pin 3 is where the tiny_IRremote library sends its output to by default. Normal LED connected to pin 2 (PB3, 220ohm current-limiting resistor). We will use this LED as a status indicator to 1) signal power-on 2) signal battery low Pushbutton connected to pin 6 (PB1, 10Kohm pull-up resistor). We will use this as a soft switch to turn the virtual wall on/off. The Arduino source code is available here . Note: I configured ATtiny85 to run at 1MHz for additional power saving. Correspondingly, in  tiny_IRremoteInt.h , I had to change  #define SYSCLOCK  from 8000000 to 1000000 . Some highlights of the code: Pin change interrupt is used to monitor when the pushbutton is pressed to turn on the unit. In normal operation, status LED flashes every second. Watchdog timer interrup

DIY Roomba Virtual Wall

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Recently, my Roomba virtual wall broke. Not sure what happened. I did a battery change, and the darn thing will not power up after the new batteries were inserted. Anyway, while looking online for a new virtual wall to buy, I came across info on people making their own virtual walls. Here is a links dump: https://petezah.com/category/development/roomba/ https://www.thingiverse.com/thing:3104027 http://blog.batmule.dk/posts/2019/Roomba_Virtual_Wall_part1/ http://www.robotreviews.com/chat/viewtopic.php?p=65658&mobile=on https://misc.ws/2014/02/27/diy-virtual-wall-for-roomba/ https://misc.ws/2014/08/09/diy-virtual-wall-for-roomba-part-two/ http://www.enide.net/webcms/index.php?page=virtual-wall-for-roomba http://eka.tomeczko.pl/index.php/diy-roomba-virtual-wall http://gregthielen.me/blogstuff/2017/06/27/roomba-virtual-wall/ https://github.com/MKme/Roomba http://forkthings.com/2016/11/25/diy-an-irobot-roomba-virtual-wall/ Turns out it is extremely easy to produce the IR signal emitted

Encode with Handbrake without slowing your machine to a crawl

Recently found out about this useful option when encoding using Handbrake . Add " pools=x " to "Advanced Options" under the "Video" tab. It will make your machine less laggy during encoding.

Re: How to enable SMB1 on Windows 10

Hit by this issue again, after a recent update to Windows 10, which I think disabled SMB1 silently. Look, I know SMB1 is dated and has security issues and all, but we all have old equipment that we need to connect to and don't always have the means or resources to replacement them. Quick reminder to self on how to enable SMB1: Launch PowerShell in Administrator mode Run " Enable-WindowsOptionalFeature -Online -FeatureName smb1protocol " Will be prompted to restarts Windows (sucks, I know..)