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https://www.theregister.co.uk/2019/06/20/ge_lightblulb_reset/

In other news, a few months ago my microwave oven keypad broke; the
first two rows of numbers quit working, 012 and 345. That made things
tricky. Had to cook things for 6:66 minutes and seconds. Setting time
was hard. I assumed that some trace had broken in the membrane thing.

So last night we had a brief power failure, and now it all works! I
don't understand how that's possible.





--  

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement  

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Re: smart bulb
On Thursday, June 20, 2019 at 3:47:21 PM UTC-4, John Larkin wrote:
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Are you joking?  A friend had an older console TV with a digital readout of
 the channel.  Did I mention it had a picture tube?  So the digital channel
 indicator was separate from the screen.  One time it stopped working right
.  I think it was not displaying numbers at all or something similarly goof
y.  He thought it was time to tear it apart.  I told him to unplug it for a
 few seconds and then it worked.  The tiny MCU needed a good reset.  The MC
U probably is never turned off since it is likely involved in the remote co
ntrol circuit too.  

It may have been a short power glitch that knocked it silly in the first pl
ace.  His and yours.  

--  

  Rick C.

  - Get 1,000 miles of free Supercharging
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Re: smart bulb
On 6/20/19 4:13 PM, Rick C wrote:
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Most microwaves manufactured in the past 20 years that cost over $150  
have a +30 sec button




Re: smart bulb

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Mine has EASY COOK, which is +30 seconds, which works depending on
what state it is in. It's complex.




--  

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement  

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Re: smart bulb
On Thursday, June 20, 2019 at 1:13:45 PM UTC-7, Rick C wrote:
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Sounds like the MCU should have been given a finite-state-machine program, but
got a rat's-nest instead.   Real-time (interrupt driven) software is an
art that doesn't have a lot of literature and cirriculum support.

Re: smart bulb
On Friday, June 21, 2019 at 2:31:27 AM UTC-4, whit3rd wrote:
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Actually I was taught state machine design including async state machines.  I only ever once saw such a state machine, but I could understand it and could have reworked it if needed.  

I'm not going to second guess a design I know nothing about.  It did it's job with no issues for a couple of decades before needing to be unplugged for a fix.  I think that is a pretty good track record.  

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  Rick C.

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Re: smart bulb
On 6/20/19 3:44 PM, John Larkin wrote:
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Software written by EEs


Re: smart bulb

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How can one bit of code break, and be fixed by a reset?

I guess I just don't have the chops to be a programmer.


--  

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement  

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Re: smart bulb
fredag den 21. juni 2019 kl. 00.39.14 UTC+2 skrev John Larkin:
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glitch, radiation, esd etc.  gets is stuck somewhere it can't get out of and the 5 cent micro doesn't have a watchdog

Re: smart bulb
On Thursday, June 20, 2019 at 6:39:14 PM UTC-4, John Larkin wrote:
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It's not the code that "broke".  The MCU got lost by a hardware glitch.  The power supplies they use are not the best in the world and let various noise past.  

--  

  Rick C.

  + Get 1,000 miles of free Supercharging
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Re: smart bulb
On 6/20/19 6:36 PM, John Larkin wrote:
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for (size_t i = 0; i < keypad_arr_.size(); ++i) {
    for (size_t j = 0; j < keypad_arr_[j].size(); ++j) {
                                       ^
...


FUUUUUUUUUUUK!

that hopefully wouldn't make it out of production but it can ruin your day

Re: smart bulb
On 6/20/19 6:36 PM, John Larkin wrote:
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Also ask Toyota they prolly know

Re: smart bulb
On 21/6/19 10:23 am, bitrex wrote:
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Reports say their code was littered with thousands of static/global  
variables, creating almost an infinitely complex (but certainly  
un-analysable) state space.

The first thing I do before starting to look for bugs in a client's  
embedded device is make a comprehensive review of all global data. It's  
amazing how many potential bugs you can find just by looking at the  
linker map of global data.

Clifford Heath.

Re: smart bulb
On 6/20/19 8:46 PM, Clifford Heath wrote:
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global variables?

what YEAR is this???

Re: smart bulb
On 6/20/19 8:46 PM, Clifford Heath wrote:
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Functional programming is all the rage among the kids these days. No  
mutable state. Or at least as close to none (interacting with the real  
world usually requires some state)

Re: smart bulb
On 21/6/19 11:00 am, bitrex wrote:
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I wish that was true. There are some adopting it, but I wouldn't say it  
is "all the rage". The Haskell community has no desire to reach a mass  
audience, because they're so special and mass adoption would make them  
less special, so they wouldn't be able to sit back and sneer and snipe  
any more, depriving them of their favourite hobby.

A few enlightened folk are trying to blend ideas from other systems,  
e.g. Elixir is a Ruby-like FP language that runs on the Erlang VM. That  
has more chance of success.

Clifford Heath.

Re: smart bulb
On 21/06/2019 08:36, John Larkin wrote:
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If the register that controls the pin direction (input / output) of the  
IO pins that scan the keypad were to get corrupted, that would do it.  
Most people don't reinitialise the IO registers except at startup. There  
is an argument for forcing a reset from time to time, e.g. each time the  
appliance is used, but that is hard if you also keep the real time clock  
in software.

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If it had been written by real programmers, then it would need a CPU  
clock frequency higher than the oscillation frequency of the magnetron,  
and it would still be laggy. Similarly, all-vacuum-tube televisions warm  
up faster than a modern television can boot up, and the battery life of  
a modern digital radio is worse than the ones that had separate filament  
accumulators and HT batteries.



Re: smart bulb
On Fri, 21 Jun 2019 15:03:52 +1000, Chris Jones

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OK, that would do it, a flipped port control bit taking out an entire
row of a matrix scan of the keypad. Somehow. ESD maybe.

Well, it's easier to poach eggs now. (In a water bath, to slow things
down.)

This microwave, an official Amana RadarRange (tm) is quirky as hell, a
smart appliance programmed by dumb people. Like the light bulb.

The RadarRange was Raytheon's name for the first microwave oven,
introduced in 1947.


--  

John Larkin         Highland Technology, Inc

lunatic fringe electronics  


Re: smart bulb
On a sunny day (Fri, 21 Jun 2019 02:50:40 -0700) it happened John Larkin

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Using at at work?
Could it be some of your pulse experiments upset it?

OTPH what is secure?
I wrote some software for the Dlink DCS-900 IP camera many years ago:
 http://panteltje.com/panteltje/mcamip/
and found that I could just read from it without username and password...
I contacted them, and got a nice reply asking how I could write that soft..
Replied I used 'snort' (open source network intrusion detection system)
looking at what browser send...

They did seem very curious, wanted all my test files, I asked why,
never heard from them again.
I was a good camera, still using it,
but light sensitivity of CMOS sensors has since improved dramatically.

Nothing is really secure if you are motivated,
I was motivated because I did not want to run MS windows,
and they had no Linux software.



Re: smart bulb
On Thursday, June 20, 2019 at 4:14:38 PM UTC-4, bitrex wrote:
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Or a millennial.
I'm sorry... make that "sketch" by a millennial, not software.



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