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Multi input AND/OR; #4720

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andypugh merged 1 commit into from
Oct 28, 2026
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Multi input AND/OR; #4720

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36 changes: 36 additions & 0 deletions src/hal/components/and.comp
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component and "Multi input AND gate";

@BsAtHome BsAtHome Oct 24, 2026

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The component naming and and or may prove confusing with and2 and or2. That is why I called them and_n and or_n. The underscore is converted into a dash for the hal internals, but if you don't like that, then you can use names=.

So, any particular reason to the naming?

@dirkx dirkx Oct 25, 2026 •
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None particularly; but _n seeded a bit extra. Changed to _n.

pin in bool in##[128:personality] = 1 "input pins, up to personality-1";

@BsAtHome BsAtHome Oct 24, 2026

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Is 128 not excessive?

Can you give an example where you'd need more than 40..50 inputs AND'ed together?

@dirkx dirkx Oct 25, 2026

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So the case I have here/that started here was steps control in a 2D conveyer belt/palletrizer is 4x5 position = 20 pallets x (8 mount sensors) + 5 normal interlocks. So I rounded up to the next multiple of 2. Happy to make that 64.

@dirkx dirkx Oct 25, 2026

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The other case is a pneumatic sorter where I have two sets(in/out) of blockage/low-pressure/high pressure detects in each of the 41 (don't ask -- I suspect the designer mixed inches v.s metric) linear stations. Though in this case you could roll up each of the 2x3 sets into a 41 OR and then combine each pair with a normal OR into the 3 outputs needed for the pump/tank.

@BsAtHome BsAtHome Oct 25, 2026

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Convinced. I guess it would probably be better to use 255 instead of 128. That would give pins in-00 through in-99 and then three digits up til in-254.

The reason for not having this at 256 is that logic uses the last byte (does personality & 0xff). That effectively creates pins 0..254 on the outset in logic.

pin out bool out "output pin; the AND of all inputs";

description """
The *out* pin is set to *TRUE* if all the inputs are all *TRUE*; or *FALSE* if one or more are *FALSE*.

The value for a unconnected pin is TRUE; so it is fine to leave a pin unconnected.

Set the number of pins via personality. The default value is a single *AND* with 8 inputs; so personality=8. The maximum number of inputs is 128 (hardcoded). If there are no inputs specified (personality=0); then the output value
is TRUE.
""";

function _ "Logical AND";

@BsAtHome BsAtHome Oct 24, 2026

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Here you add a doc string. But in the or you don't. Not consistent. You may also want to elaborate... I think it is rather obvious that it calculates the logical AND. But what makes this so special, that is why you document it.

@dirkx dirkx Oct 25, 2026

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ok - will fix by removing this for the AND


see_also """
*or*(9),

@BsAtHome BsAtHome Oct 24, 2026

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Please don't use emphasis. The post-processor cannot handle it and links will no longer be provided in the html version.

@dirkx dirkx Oct 25, 2026

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Grin :) took it from one of the other modules; now removed.

and2(9)
and
or2(9).
""";

option period no;
option default_personality 8;
option default_count 1;

@BsAtHome BsAtHome Oct 24, 2026

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The default count is implicitly one. Why set it?

@dirkx dirkx Oct 25, 2026

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Grin :) took it from one of the other modules - removed :)


license "ASLv2";

@BsAtHome BsAtHome Oct 24, 2026

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What type of license is that?

It would probably fail for RTAI because anything not GPL will taint the kernel.

Besides, if you need this specific license, then it must also be added to debian/copyright, which needs consensus to ensure compatibility.

@dirkx dirkx Oct 25, 2026 •
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changed to GPL; Was the Apache Software License v2

author "Dirk-Willem van Gulik <dirkx(at)webweaving(punto)org";
;;
FUNCTION(_) {
bool tmp = 1;
// we prefer constant time; so do not return 0 on the first 0.
for(int i = 0; i < personality; i++)
tmp = tmp && in(i);
out_set(tmp);
}
33 changes: 33 additions & 0 deletions src/hal/components/or.comp
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component or "Arbitrary input OR gate";

@BsAtHome BsAtHome Oct 24, 2026

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The AND gate you use the term "Multi". Why is this "Arbitrary"? What is arbitrary about these inputs?

Why not retain the comp doc string I wrote?

@dirkx dirkx Oct 25, 2026

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Done

pin in bool in##[128:personality] = 0 "in";

@BsAtHome BsAtHome Oct 24, 2026

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The doc string "in" is a bit thin, isn't it?

@dirkx dirkx Oct 25, 2026

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Grin :) took it from one of the other modules - elaborated :)

@dirkx dirkx Oct 29, 2026

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Ok - was not able to remove it - as a "" or none will give corrupted output / seems to concatenate the in and out. So have instead made it a more elaborate string.

pin out bool out "output pin; the OR of all inputs";

description """
The *out* pin is set to *TRUE* if any the inputs is *TRUE*; or *FALSE* if all are *FALSE*.

The value for a unconnected pin is FALSE; so it is fine to leave a pin unconnected.

Set the number of pins via personality. The default value is a single *OR* with 8 inputs; so personality=8. The
maximum number of inputs is 128 (hardcoded). If there are no input pins at all (personality=0); then
the output is *FALSE*.
"""
;
function _;
see_also """
and(9), and2(9) and or2(9).
""";

option period no;
option default_personality 8;
option default_count 1;

license "ASLv2";
author "Dirk-Willem van Gulik <dirkx(at)webweaving(punto)org";
;;
FUNCTION(_) {
bool tmp = 0;
// we prefer constant time; so do not return 0 on the first true
for(int i = 0; i < personality; i++)
tmp = tmp || in(i);
out_set(tmp);
}
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