From efd30cdf8ac8aa1ff1b28bcad5c00aa9993ca7c9 Mon Sep 17 00:00:00 2001 From: Benjamin Koch <bbbsnowball@gmail.com> Date: Mon, 1 May 2023 18:04:11 +0200 Subject: [PATCH] add some thoughts on which signal to put on which wire --- README.md | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 95 insertions(+), 2 deletions(-) diff --git a/README.md b/README.md index 3f7fed7..e2b6833 100644 --- a/README.md +++ b/README.md @@ -64,8 +64,6 @@ RP2040 microcontroller (like Raspberry Pico), power supply, terminal block and m [PDF with rendering of PCB layers](./c3pb-heizung/generated/PCB/PDF/c3pb-heizung-assembly.pdf) - - Anschlussklemmen: Es gibt leider kein Bild in richtig herum. Man kippe sie im Kopf um 90 Grad nach links-oben und die Kabel kommen dann von links-oben.  @@ -120,6 +118,101 @@ e.g. with suitable slots in the case instead of making a complete hole for the b how well touch is working. +Gehäuse +------- + + + +Die meisten Maße stehen im Datenblatt, aber für uns ist auch die Materialstärke vom Deckel relevant. Die scheint 1.5 mm zu sein bzw. 1.2 mm +an den dünneren Stellen (gemessen mit der Mikrometerschraube von Paulimot). Das wäre deutlich dicker als die LEDs, d.h. man könnte versuchen, +die nicht ganz durch zu fräsen. + +tioan war nicht wirklich glücklich mit der Wahl, aber das war die einzig sinnvolle beim Hornbach (Preis, Größe und Form). Für zukünftige +Projekte ggf noch mal mit ihm reden - er meinte, im Großhandel gibt's bessere zur Auswahl. + + +Kabel +----- + +fxk8y hatte [Helukabel 18090](https://www.tme.eu/de/details/liyy7x0.5/mehraderleitungen-ohne-abschirmung/helukabel/18090/) vorgeschlagen +(aber nicht bei TME kaufen - ist woanders günstiger). 7-polig ist wohl recht üblich. Das sind 0.5 mm². Laut Faustregel kann es grob 5 A +und laut Hersteller 6 A (aber ggf. sollten wir ein Derating anwenden je nach Art der Verlegung). Wir planen je zwei Adern für 24V und GND +zu nehmen, d.h. 10-12 A. Die Klemme kann 12 A, das PCB hoffentlich auch. + +There doesn't seem to be any standard coloring for the wires of RS485 so we rather +arbitrarily choose [this](https://www.baranidesign.com/faq-articles/2020/3/23/meteotemp-meteowind-rs485-wire-colors-and-electrical-connection) +because it somewhat matches our intuition. Furthermore, we should satisfy these conditions: + +1. RS485 A and B next to each other. +2. Wires around RS485 have symmetric influence, e.g. 24V next to A and GND next to B would + be bad because current flows in the opposite direction and will create an unbalanced + voltage in the RS485 lines. +3. WS2812 next to signals that balance each other out, e.g. both RS485 lines are fine but + not only one of them. + +Option 1: This is similar to our first, intuitive idea but with two power lines swapped to satisfy condition 2: + +<table style="border: none !important; border-collapse: separate; text-align: center"> +<tr> + <td style="width: 1.5em; height: 3em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: green solid 0.5em; border-radius: 2em; background: none;" colspan="2">A+</td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: #fb0 solid 0.5em; border-radius: 2em; background: none;" colspan="2">B-</td> + <td style="width: 1.5em; height: 3em; padding: 0px; margin: 0.1em; border: none; padding: 0px;"> </td> +</tr> +<tr> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: brown solid 0.5em; border-radius: 2em; background: none;" colspan="2">24V</td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: blue solid 0.5em; border-radius: 2em; background: none;" colspan="2">GND</td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: gray solid 0.5em; border-radius: 2em; background: none;" colspan="2">24V</td> +</tr> +<tr> + <td style="width: 1.5em; height: 3em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: white solid 0.5em; border-radius: 2em; background: none;" colspan="2">GND</td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: pink solid 0.5em; border-radius: 2em; background: none;" colspan="2">WS</td> + <td style="width: 1.5em; height: 3em; padding: 0px; margin: 0.1em; border: none; padding: 0px;"> </td> +</tr> +<tr> + <!-- dummy line to force columns to the right width --> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> +</tr> +</table> + +Option 2: WS2812 signal on center wire. This is not such a good match for intuition (blue is a signal and pink is GND) but all influences should cancel out and the central wire is not a power wire (i.e. doesn't get warm). This makes the most sense from a technical perspective. + +<table style="border: none !important; border-collapse: separate; text-align: center"> +<tr> + <td style="width: 1.5em; height: 3em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: green solid 0.5em; border-radius: 2em; background: none;" colspan="2">A+</td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: #fb0 solid 0.5em; border-radius: 2em; background: none;" colspan="2">B-</td> + <td style="width: 1.5em; height: 3em; padding: 0px; margin: 0.1em; border: none; padding: 0px;"> </td> +</tr> +<tr> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: brown solid 0.5em; border-radius: 2em; background: none;" colspan="2">24V</td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: blue solid 0.5em; border-radius: 2em; background: none;" colspan="2">WS</td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: gray solid 0.5em; border-radius: 2em; background: none;" colspan="2">24V</td> +</tr> +<tr> + <td style="width: 1.5em; height: 3em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: white solid 0.5em; border-radius: 2em; background: none;" colspan="2">GND</td> + <td style="width: 3em; height: 3em; padding: 0px; margin: 0.1em; border: pink solid 0.5em; border-radius: 2em; background: none;" colspan="2">GND</td> + <td style="width: 1.5em; height: 3em; padding: 0px; margin: 0.1em; border: none; padding: 0px;"> </td> +</tr> +<tr> + <!-- dummy line to force columns to the right width --> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> + <td style="width: 1.5em; height: 0.1em; padding: 0px; margin: 0.1em; border: none;"> </td> +</tr> +</table> + + Zusätzliche Nutzung =================== -- GitLab