beta3

Over the Easter weekend, I had some time to follow @maehw 's instructions to build a DIY infrared tower to connect to the #lego #mindstorms RCX module (see here: https://github.com/maehw/DiyIrTower)

My original IR tower did not work anymore after 25+ years and I'm very grateful for this opportunity to re-activate this set.

Apr 6 at 3:29pmWeb
Show threadbeta3Apr 6
Here's a list of points at which I slightly got stuck. Maybe it's helpful for others who try to do it in a similar way:
(1) For the includes "<avr/io.h>" and "<avr/interrupt.h>" in the firmware it took me a moment to realized that the corresponding libraries are packaged in avr-libc.
Show threadbeta3Apr 6
(2) I didn't immediately understand that the "programmer" (ISP) is a dedicated piece of hardware. My brother-in-law then gave me an Arduino board to use it as the programmer. (The corresponding firmware is part of the examples to be found in the Arduino IDE.)
Show threadbeta3Apr 6
(3) While one can then use avrdude with Arduino as the programmer, the programmer "arduinoISP" is *not* the correct one for this purpose. The simplest option for me was to add the ATtiny as a board in the Arduino IDE (see instructions here: https://github.com/sleemanj/optiboot/blob/master/dists/README.md#installation--usage), and then use the avrdude binary and config files located in the (hidden) Arduino configuration folder. (The precise avrdude syntax used by the Arduino IDE by activating "show verbose output during upload" in the preferences).
Show threadbeta3Apr 6
(4) It took me a while to figure out that it's necessary to give Chromium on Ubuntu (which is a snap package) special permissions to use the serial port by running "sudo snap connect chromium:raw-usb". (During the installation of Arduino ID, it was also suggested to add my user to the group "dialout", but I'm not sure if this was really necessary).
Show threadbeta3Apr 6
(5) I had to play a little bit with the angle of the IR LED before the connection with the RCX module was established successfully.
Show threadbeta3Apr 6
(6) For ordering parts: The board to which the electronic components are pinned is called a "breadboard". The wires making connections on the board are called "jumper wires".
Show threadMäh W.Apr 8
@beta3 wow, thank you very much for that important feedback. When I find time, I'd like to add this beginner friendly info to the README in the repo. In case you're interested in PCB Rev. 1 (with some minor hardware), I can also send you some bare PCBs in case you're located in DE/AT. But your breadboard setup looks great!
Show threadbeta3Apr 8
@maehw Thanks for the offer! For now I'd just leave it like it is and check if my kids develop some interest in it when we play around with some simple Mindstorms example. (So far, they've just built some static "robots" with many tentacles while I was getting everything to work again. :D)
Show threadirrational methodApr 6

@beta3 @maehw

Nice, I got my old IR tower working a couple of weekends ago. Took me about an hour to realize it required a 9V battery, even though I could see the light blinking.

Still need to replace more than two of the lego wires... The 24awg wire I bought has a thick insulation that doesn't work nicely with the lego connectors.

Show threadbeta3Apr 6
@IrrationalMethod @maehw Yeah, fixing the wires is next on my list. I'm trying now to add insulation tape at the position where the cable is blank. I hope that suffices for the beginning. But let me know if you have any advice for this step. :)
Show threadirrational methodApr 6

@beta3 @maehw

I need to write up a blog post!

I found some Instructables guides that had some helpful information, but recommended soldering the wires inside the brick. I managed to do one cable that way without melting the plastic, but I've also been trying to use the little prongs that push into the insulation. It's possible to put it back together with a little C clamp. I might build a jig to help hold everything in place.

28awg (apologies for the American-ism here) jumper wires are too small to be secured, or so it seems. The 24awg speaker wire works OK, but as I said, is a tight fit and doesn't always work on the first try.

I am trying to order 26awg from my usual supplier but they don't have any 2 conductor wire in stock for another couple of weeks.

Edit: broke the thread with a followers only post, but photos of the inside of the connectors here:
https://social.coop/@IrrationalMethod/116358710376425687

irrational method (@[email protected])

Attached: 3 images @[email protected] @[email protected] Some photos of popping open the connectors. I don't think I did (much) damage once I got the hang of this with a small flathead.

social.coop
Show threadMäh W.Apr 8
@IrrationalMethod @beta3 Do you know the following video on YouTube by user BatteryPoweredBricks? ➡️ https://youtu.be/kXApTUbNzD0
Replacing Lego 9v Wire / Repairing Mindstorms Sensors

YouTube
Show threadMäh W.Apr 8
@IrrationalMethod @beta3 TL;DW: He is using 24 AWG 6P cable. So you can basically use it for 3x 2P. Is recommend watching the video. Details about the product are in the video description over there.
Show threadirrational methodApr 9

@maehw @beta3

Oh perfect, thank you -- i'm watching now.

Show threadirrational methodApr 9

@maehw @beta3

Oh yeah, the Jameco wire is what I was trying to use -- the insulation is too thick.

Show threadMäh W.Apr 9
@IrrationalMethod @beta3 It worked for me. 🫤
Show threadirrational methodApr 9

@maehw @beta3

The 6 conductor wire he says works best is closer to what I was planning to buy next. I'm going to see if I can buy that brand, or a similar product.

Show threadMäh W.Apr 9
@IrrationalMethod @beta3 ah sorry, was not aware of the brand names. I got me the 6 conductor wire.