Temperature Measurement

I concur, having been Eng Mgr at C-MAC who supplied trivial Electrical Seat heater circuit boards to Scandmec> Johnson Controls> Chrysler for Jeep Che rokees.

For final qualification, Chrysler drove 2 Cherokees towards Churchill MB on Hudson's Bay with -40'C winter temps and an Engineers from Omron, Japan in spect our FUJI pick and place machines. One of the Eng. put his fingers on the machine to detect the vibrations which is a measure of low vibrations f rom good preventive maintenance which we did. That was my favourite trick i n the 80's when I qualified Seagate and Japanese HDD magnetic drives was to listen to bearing noises of hard disk drives. Then we tested Fujitsu at -4

0'C with dry ice in a picnic box. It squeeled for 1 second, spun up and th e heads flew and W/R data error free. (US Military test requested)

44c at QTY 100 from LCSC

there's several cheaper parts with more leads.

possibly LM35, or whatever its predecessor was. but they're analogue output.

--
  Jasen.

and if using avr-gcc mosty arduino, float and double are the same, 4 bytes

ned here

the

d the

iving

voltage

it ADC,

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eption, $2 at quantity. I was looking at the TMP236 which is only $0.20 in qty.

I don't think we can specify LCSC possible counterfeits for medical gear.

oltage control that has a well established temperature offset so that it ca n be used to measure that temperature. It might not be a sub dollar part, so it may not be useful here either. I just don't recall what it is, but it was discussed in a thread recently. Seems everyone knows about it but m e.

ut.

Yeah, that's fine. The TMP236 I found is analog which simply requires an A DC (already allocated for the thermistor) and power. Seems to be a good, l ow cost part. I just thought there might be something better.

--

  Rick C. 

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I have a 5372A, which I bought for frequency-compensating fancy PLLs, but it's such a pain to set up that I hardly ever use it.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC / Hobbs ElectroOptics 
Optics, Electro-optics, Photonics, Analog Electronics 
Briarcliff Manor NY 10510 

http://electrooptical.net 
http://hobbs-eo.com

We build high speed networking kit.

Generally our stuff uses SFP modules. They have an I2C interface "on the side" for querying parameters and monitoring various things.

Realistically this means that we have to deal with I2C on an externally visible connector, where the customer can plug any random crap into it, and in practice they do, and we get bug reports about it.

Of course it's always our fault, and never the fault of the vendor who sold them the dodgy SFP module.

We learned years ago that each SFP cage needs its own dedicated I2C bus which can be disconnected entirely from anything else at the electrical level if needed, so we can guarantee that it can't wedge anything else when it goes wrong.

Mike

On a sunny day (Fri, 12 Jun 2020 20:33:38 +0100) it happened Tom Gardner wrote in :

...

I have done a lot of Z80 coding, asm wrote a CP/M clone in asm, had the Software Toolworks C compiler and math library for it wrote a z80 disassembler:

Also wrote a multi tasking OS for it.. Nice chip, never a problem. Designed all the hardware around it:

Yea, linked lists I use a lot, not sure if it matters much in C what the processor architecture is..?? I was reading Apple is moving to RISC.... (from x86).

OTOH there is a lag between reality and industry mass movement. We see a movement to ever more complex bloated shit where thing are written by people who have no clue about hardware and electronics...

Most things can be done with a Microchip PIC, really, at a fraction of the cost, faster boot times, lower power consumption, lower cost. Linux is getting more bloated, systemd sucks, Linux is is not even a real time system. just use a PIC for every task..

Hey, I know I am controversial here, and yes I have a quad core Xiaomi cellphone now and sure you can make videos with it.. but for 2$50 you can do this with a PIC:

It is the musician, not the instrument

Elon M. flies to the ISS with touch screens he want to g to mars with those How many instruments will still be working when he arrives there? One high energy particle hit at the right place and you lose your screen driver chip and with it all your instruments! Better use some old mechanical voltmeters ;-)

(Ducks)

Anyways, I had the feeling yesterday there is a WW3 coming, this is usual after a big recession. As it will be nukes all over the place most 'tronics will no longer work, China has the solution Suanpan:

They will probably win anyways ;-)

I've used Whitesmith's C compiler on a Z80. While I would have looked at the assembly code, I can only remember one thing: there is no instruction that allows out(aPort, aByte) where aPort is not fixed at compile time.

The workaround is the usual unpleasant hack: at runtime synthesise the subroutine on the top of the stack, then execute it.

The Z80 hardware was nice, agreed.

Apparently Apple's own version of an ARM processor.

They've managed similar transitions before, made possible by them controlling the software development toolchain.

I had a brief looks at PICs a few years ago, thought the onboard hardware looked reasonable, but thought the processor architecture was horrible - all the style and class of the 8051. I gave up and looked elsewhere before realising that they have some radically different architectures that are probably better.

Normally I would tend to agree about Linux and realtime, but since it is the weekend I'll point to this counter example.

IN its capsules SpaceX uses lightly customized Linux built with PREEMPT_RT patches for better real-time behavior.

While tried and tested (and hence old) hardware and software are used in space applications for good reason, is SpaceX really using Linux

2.4 kernels ?

Version 2.4 and older really required the kernel pre-empt patch for a decent RT performance. Version 2.6 and later contained most of these features as standard.

I've had endless problems with I2C over the many bitter years of its existence. Power cycling is good. I'm amazed that so many people test an I2C system using only a cheap I2C adapter based on a standard micro with an I2C port. I built my own tester that allows me to test with all timings within spec, on the margin and just outside. At 100kHz clock it isn't hard. One day I'll get round to doing an FPGA based one that can do the faster speeds. When I last searched for things to buy I found two, one at about $10k and another (which claimed to be used by chip makers) at $40k+.

MK

The best thing about SFPs is that they just work if you apply about

3.3 volts and ignore the I2C interface.

This is a 2 GHz square wave, as fast as the SRS clock generator goes.

A 10 Gbps SFP is amazing for around $20. I would have figured that $1000 would be a fair price.

--

John Larkin         Highland Technology, Inc 

Science teaches us to doubt. 

  Claude Bernard

On a 5370, if, say, you want to display the mean and std deviation of every 1000 shots of a time interval measurement, you just punch a few big buttons. Our new Keysight counters simply can't do that measurement, and are a nightmare to set up anyhow.

The jitter measurement noise floor of the 5370 was about 30 ps RMS. The new Keysight, roughly 40 years later, is about 15.

There was some chinese genius at HP who invented a lot of great stuff.

--

John Larkin         Highland Technology, Inc 

Science teaches us to doubt. 

  Claude Bernard

The 5372 is a good instrument if your job responsibilities are limited to jitter measurements, or you have time on your hands for other reasons. I don't want to diss the box as such, which s an amazingly well developed universal counter with CRT display, but that just isn't my gig.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC / Hobbs ElectroOptics 
Optics, Electro-optics, Photonics, Analog Electronics 
Briarcliff Manor NY 10510 

http://electrooptical.net 
http://hobbs-eo.com

I do ! But, strangely given all the reports, I put it in, then have never had to use it.

Cheers, James Arthur

The 68k family had very slow hardware division (and that's just for the sizes it supported in hardware). Later devices in the family dropped the hardware division instruction when someone realised a software division routine in straight m68k assembly was faster than the hardware instruction!

Oh, I think the PIC is in a class by itself, somewhere far below the 8051.

But there are two nice things about the PIC. One is that Microchip believe that if they first sell a device, they should keep selling it for ever - they stay on the market for a /long/ time.

The other is that the chips are incredibly robust. We once had a

higher. So they asked us for advice and suggestions, to see what the

I agree that you'd need a good definition here to make engineering decisions. But this sort of thing is more management decision, or bureaucrat decision, and they don't need measurable quantities!

I'm afraid you'll have to talk with the people doing the "verifying" to see what they really mean.

That's MY point. But people on the team seem to want to pick a part based on biases without making any effort to identify requirements for the part. I'm pretty sure they picked a motor that way and an oxygen sensor. Whatev er. I am not vested in the project. I'm just giving advice now. The oxyg en sensor someone picked has very poor docs. The app note for the company' s products covers a lot, but apparently not this one. A reference design f rom this app note was used and it would not work at all I'm sure. I simula ted a circuit I think will work and posted it to Google drive. I've been w aiting a while to hear back about it. Whatever. Guess I'm losing interest in the project.

--

  Rick C. 

  +-+ Get 1,000 miles of free Supercharging 
  +-+ Tesla referral code - https://ts.la/richard11209

One cannot measure temperature without changing the temperature.