Clive "Max" Maxfield received his BSc in Control Engineering in 1980 from Sheffield Hallam University, England and began his career as a designer of central processing units (CPUs) for mainframe computers. Over the years, Max has designed everything from silicon chips to circuit boards and from brainwave amplifiers to steampunk Prognostication Engines (don't ask). He has also been at the forefront of Electronic Design Automation (EDA) for more than 30 years.

Re: Question regarding esistor tolerances

Reply posted 3 days ago (09/21/2020)
I wish one of us knew someone who works in a resistor manufacturing facility today!!!

Re: Question regarding esistor tolerances

Reply posted 3 days ago (09/21/2020)
OMG -- that is another twist!!!   I would never have thought of this one -- Max

Re: Question regarding esistor tolerances

Reply posted 3 days ago (09/21/2020)
"...perhaps dates to vacuum tube days when human labor was cheaper..." I wasn't trying to suggest that the grading was done by hand -- just that the 1% parts were...

Re: Question regarding esistor tolerances

Reply posted 3 days ago (09/21/2020)
One way would be to vary the price -- if you make 1% resistors 100X more expensive, then a lot of designers will decide that 5% is "good enough" LOL
I quite like back-to-back NAND gates myself LOL
Ns Antedeluvian noted in his comment above, I wasn't actually looking for a circuit, but this one is very interesting because it's a twist on one I documented in...
That's a good point about a tiny micro
Thanks Aubrey -- I love your trimpot suggestion -- I fear that since so many people misunderstood my question, it's probably my fault for not articulating it well...
Actually, I did a 9-part mini-series on switch-bounce (see links below) -- I used to be a hardware fan -- then a software supporter -- now I love the debounce chips...

Question regarding esistor tolerances

New thread started 5 days ago
When I was starting out in engineering ~40 years ago, I was told that if a resistor manufacturer was making a bunch of 10K resistors, for example, then their actual...
I need to write a column about using hardware techniques to debounce switches -- if the circuit included an MCU we could do the debounce in software, so I'm looking...

Re: When is a State Machine not a State Machine?

Reply posted 2 months ago (07/21/2020)
"This is just an example of a bigger issue of the fuzzy terminology of our discipline."I'm guessing you aren't a fan of Fuzzy Logic LOL

Re: When is a State Machine not a State Machine?

Reply posted 2 months ago (07/21/2020)
"Of course, you can hold the viewpoint that 'everything is a state machine'."Are you calling my dear old mother a state machine? LOLIn reality, I would say that...

Re: When is a State Machine not a State Machine?

Reply posted 2 months ago (07/21/2020)
"No! The code you are showing is NOT a state machine. In fact, it is an antithesis of a state machine."Don't hold back -- tell me what you really think LOL.While...

When is a State Machine not a State Machine?

New thread started 2 months ago
Suppose we have a loop() function in an Arduino sketch (program) that looks like the following:void loop(){    digitalWrite(PinLed, HIGH);    delay(1000);   ...

Re: How Can Hairy Global Variable be Hidden Away?

Reply posted 2 months ago (07/15/2020)
Awesome -- thanks so much for your help -- Max

Re: How Can Hairy Global Variable be Hidden Away?

Reply posted 2 months ago (07/15/2020)
Hi Manoweb -- thanks for your feedback -- On the one hand I'm tempted to go back and change everything to binary strings -- on the other hand, I have memory...

Re: How Can Hairy Global Variable be Hidden Away?

Reply posted 2 months ago (07/14/2020)
Thanks so much for taking the time to explain this stuff. Just one more question (for now LOL)Do I have to use both extern and const at the front of the program...

Re: How Can Hairy Global Variable be Hidden Away?

Reply posted 2 months ago (07/13/2020)
Hi Kocsonya -- thanks so much for your feedback. Re your points -- I'll take them in reverse order:2. This is a really good point -- as you say, probably not significant...

Re: How Can Hairy Global Variable be Hidden Away?

Reply posted 2 months ago (07/13/2020)
I've been thinking (don't laugh; it's true). Would you agree that:-- For software developers creating applications to run on high-level systems like PCs, the keyword...

Re: How Can Hairy Global Variable be Hidden Away?

Reply posted 2 months ago (07/13/2020)
AWESOME!!! I just tried using the "extern" approach and it worked like a charm/ Every day I learn something new -- thank you for your sage advice!!!

How Can Hairy Global Variable be Hidden Away?

New thread started 2 months ago
Hi there, sorry to bug you with yet another stupid coding question (I R a hardware design engineer). This is related to my 12x12 ping pong ball array where each...

Re: Do I need this mask and cast?

Reply posted 3 months ago (07/08/2020)
I just saw this part -- AWESOME -- will the first comparison stay there for awhile? (Can I link to it from a magazine column?)

Re: Do I need this mask and cast?

Reply posted 3 months ago (07/08/2020)
Quick question -- so if I have an 8-bit signed int (int8_t) containing -128 (0x80), I know that if I cast this to a 32-bit signed int (int32_t), it will be sign...

Re: Do I need this mask and cast?

Reply posted 3 months ago (07/08/2020)
Hi Jms_nh -- I am awed by the amount of work you put into this response -- thank you so much for all of this -- it's very much appreciated -- Max

Re: Do I need this mask and cast?

Reply posted 3 months ago (07/07/2020)
Hi Manoweb -- this is very useful feedback -- I've added it to my mental list of "pros" :-)

Re: Do I need this mask and cast?

Reply posted 3 months ago (07/07/2020)
Hi Cprovidenti -- when you say "...it is so self-evidently redundant..." I fear you are looking at this through the eyes of someone who already knows this stuff.I...

Re: Do I need this mask and cast?

Reply posted 3 months ago (07/07/2020)
...

Re: Do I need this mask and cast?

Reply posted 3 months ago (07/07/2020)
Hi Jmdhuse -- I'm with you -- I think it's best to write the code so anyone reading it in the future (and that could easily be me) can understand what it was I was...

Re: Do I need this mask and cast?

Reply posted 3 months ago (07/07/2020)
LOL I'll have to remember that line. But you make a good point -- if the optimizer doesn't perform it's task, my superfluous statements could potentially impact...

Do I need this mask and cast?

New thread started 3 months ago
This is just a quick question -- take a look at the following function:uint8_t GetBlue (uint32_t tmpColor){    return (uint8_t) (tmpColor & 0xFF);}I'm writing...

Re: To Cast, or Not to Cast

Reply posted 3 months ago (06/26/2020)
Awesome -- thanks so much for taking the time to explain all of this -- Max

Re: To Cast, or Not to Cast

Reply posted 3 months ago (06/26/2020)
Good point, but the way the algorithm works is that the worst case will be to have GetRed() always return values of 255. In this case, we will have an intermediate...

Re: To Cast, or Not to Cast

Reply posted 3 months ago (06/26/2020)
I do like using parentheses to explicitly show what I'm trying to do -- and doing so can help a lot with precedence issues.

Re: To Cast, or Not to Cast

Reply posted 3 months ago (06/26/2020)
Hi there, this helps a lot -- thanks so much -- Max

Re: To Cast, or Not to Cast

Reply posted 3 months ago (06/26/2020)
OK, in the following statement, tmpRed has been declared as a uint32_t. Also, I've modified the GetRed() function to return a uint8_t.tmpRed =   ( (  GetRed(startColor)...

Re: To Cast, or Not to Cast

Reply posted 3 months ago (06/26/2020)
...

Re: To Cast, or Not to Cast

Reply posted 3 months ago (06/26/2020)
Hi Mike -- do you have a minute to discuss this (256 970 1906)?

Re: To Cast, or Not to Cast

Reply posted 3 months ago (06/26/2020)
Sorry -- I should have said -- it's my pathetic attempt at C.The target processor dev board is a Seeeduino XIAO, which has a 32-bit Arm Cortex-M0+ (and which is...

To Cast, or Not to Cast

New thread started 3 months ago
Hi there -- sorry to bug you with a newbie question, but I'm a hardware design engineer, so software sometimes leaves me a bit confused.Can you take a quick glance...

Re: Is char signed/unsigned and is >> on signed defined?

Reply posted 4 months ago (06/03/2020)
Oooh, a "Nerds Hamilton" -- I can imagine the queues of nerds stretching down the street and round the corner. I just took a look on Amazon -- this book does look...

Re: Is char signed/unsigned and is >> on signed defined?

Reply posted 4 months ago (06/03/2020)
"See 'Writing solid code'"  Is that a book (or a stage play)?

Re: Is char signed/unsigned and is >> on signed defined?

Reply posted 4 months ago (06/03/2020)
Great point -- thanks for sharing -- Max

Re: Is char signed/unsigned and is >> on signed defined?

Reply posted 4 months ago (05/28/2020)
There's a "long long"? Where will this madness end?(Does every C compiler support the long long data type?)

Re: Is char signed/unsigned and is >> on signed defined?

Reply posted 4 months ago (05/27/2020)
Awesome info -- thanks Kocsonya

Re: Is char signed/unsigned and is >> on signed defined?

Reply posted 4 months ago (05/27/2020)
Now I know why I became a hardware engineer rather than a software developer LOL

Re: Is char signed/unsigned and is >> on signed defined?

Reply posted 4 months ago (05/27/2020)
I pity the person who is tasked with maintaining your code when you retire LOL

Re: Is char signed/unsigned and is >> on signed defined?

Reply posted 4 months ago (05/27/2020)
I'm good at asking questions -- it's when answering them that I fall down LOL

Re: Is char signed/unsigned and is >> on signed defined?

Reply posted 4 months ago (05/27/2020)
Hi indigoredster -- thanks for the feedback -- it's a shame (a) these holes were left in the original spec and (b) they haven't been patched over the years -- Ah...

Re: Is char signed/unsigned and is >> on signed defined?

Reply posted 4 months ago (05/27/2020)
Do you know any examples of compilers that DO NOT shift copies of the sign bit in when performing a >> operation on signed integers?

Re: Is char signed/unsigned and is >> on signed defined?

Reply posted 4 months ago (05/27/2020)
I see "The quotient is rounded toward zero."  I'm assuming this is because the rounding is basically a truncation operation, but this will make positive numbers...
Hi chaps and chapesses -- sorry to bug you again -- this is a follow-on to my previous question: What size variables are best for 8-bit, 16-bit, and 32-bit MCUs?...
Hi Jmford94 -- I think you offer sage advice -- I'm so glad I posted this question because the various responses have helped shape the way I go forward.
OMG There were THREE typos in each one (there aren't any now) -- for other readers, the way it was when I just went to look was:   for (int8_t i = 0, i < 100,...
This is awesome -- thanks so much for sharing it with me -- Max
Are they "fast" because the compiler stores them in 32-bit words even though they are 8-bit and 16-bit values?
The problem here is that an int is a 16-bit quantity on an Arduino Uno, but a 32-bit quantity on an Arduino Due -- suppose I wrote the program using int on Due and...
Hi there – I have a conundrum rattling around my head. I once read that an MCU is most efficient when its working with its natural word width. On one level...

Re: Block diagram software

Reply posted 6 months ago (04/08/2020)
I've been using Visio for longer than I care to remember (must be more than 20 years) and I love it!!!

Re: Covid-19 Stories

Reply posted 6 months ago (03/25/2020)
Hi Stephane -- Max here -- I'm based in Huntsville, Alabama, USA (I moved here from England for the nightlife -- that's a little Alabama joke right there :-)It's...

Re: Funny or Not Funny?

Reply posted 7 months ago (02/13/2020)
People are dying -- there's no way you can make that funny.There is no way you can make an ad using this topic that won't end up shooting yourself in the foot.Even...
That's something else she says LOL
If clicked, The privacy stuff stuff should pop-up in its own window so it can be dismissed without loosing any other info.
My mother asked me to tell you that you have a tremendous line-up of presenters, and she urges everyone to attend the talk by her first born son LOL

Re: Event Driven Frameworks

Reply posted 8 months ago (01/14/2020)
Have you looked at the leOS multitasking kernel for Arduino by Leonardo Miliani?

Re: Embedded Development Predictions for 2020-2029

Reply posted 9 months ago (01/09/2020)
Good question -- I think one way to look at this is to consider what we expect to be coming our way application and technology-wise, and then "work back" to what...
I passed this question to my chum, Steve Evanczuk (Editor-in-Chief of www.Embedded.com), and he responded as follows:The obvious difference is a JTAG adapter is...

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