Microchip Support is Amazing

We had one of our Microchip ICD3‘s fail last week so I put in a support ticket via the web site. I figured I wouldn’t hear back for a couple days because Microchip is right in the thick of their annual Masters engineering event. To my surprise they called me soon after to ask about the issue, find out if it was urgent (it wasn’t we keep a spare on hand) and to apologize in advance for possibly slower than normal responses due to the Masters event. Today I got a notice that a replacement ICD3 has been sent out.

Wow even with the event going on they still were able to get this all done in less than one week. Thank you so much Microchip your customer service is amazing.

PS – Their products are great too!

Windows 7 Desktop Shortcuts and USB COM port problems solved

A while back (I’ve been too busy to blog much for almost a year) I was puzzled to find some of my desktop shortcuts disappearing seemingly randomly. A page in the Microsoft Knowledge base explained why it was happening. In my particular case the shortcuts where pointing to network shares and documents and neither of the proposed solutions was right for me. Then in a flash of inspiration I realized that if I put those shortcuts inside of a folder on the desktop the System Maintenance troubleshooter doesn’t touch them.

My old XP box finally died so I had to move my USB to EIA-232 adaptors to my Win 7 box. Shuffling the devices around between various USB ports and hubs I saw the old problem of new COM port numbers being assigned to the adaptor with each USB port change. This of course rapidly leads to having to deal with COM10+. I vaguely remembered that there was a way to remove the extra ports so that once the adaptors where in their final USB destinations they’d have the low numbers I like. Searching around I found this excellent page with instructions.

See Also:
Device Manager does not display devices that are not connected to the Windows XP-based computer, from Microsfot
How to Find Hidden COM Ports, from Adafruit
USBDeview, from NirSoft

3/16/2015 Update: Updated the rttycontesting.com URL, added other reference URLS

An Insanely Intrusive EULA

UPDATE Feb. 29, 2012 – A new version of MPLAB X has been released and they removed the auditing clause completely. That makes this old post no longer applicable.

Thank You Microchip

On the Microchip forum somebody read the license agreement for their new free IDE, “MPLAB X” and found this in section 1c.

Microchip’s authorized representatives will have the right to reasonably inspect, announced or unannounced and in its sole and absolute discretion, Licensee’s premises and to audit Licensee’s records and inventory of Licensee’s use of the Software, whether located on Licensee’s premises or elsewhere, at any time, in order to ensure Licensee’s adherence to the terms of this Agreement.

What! They demand the right to enter a companies or persons premises unannounced because someone clicked yes on a EULA! It turns out this is not all that new for Microchip, a post from June 2009 says that this is also in the dsPIC dev kit EULA.

This could be a huge problem for my work, I can’t imagine the company lawyers are going to allow me to use MPLAB X with this onerous of a EULA. Thankfully all current Microchip based projects are using MPLAB 8 and their Hi-Tech C Pro compiler which do not have this condition on usage. The problem will be in five or more years when MPLAB 8 is gone and we still need to support our products (our average life cycle is 20 years). I’ll just have to remember to keep a copy of MPLAB 8 around so that I can still use their debuggers and programmers when needed in the future.

I hope they change their tune and remove this onerous clause. If they do not change this I will be forced to no longer consider Microchip processors for new projects :-(.

Thanks to Alan on the PIClist for pointing this out.

Concentricity vs. Runout

What is the relationship between concentricity and runout? I keep seeing this question come up on the net and very few places seem to give the correct answer. Usually the discussion gets bogged down and confused by people adding in circularity and/or parallelism of 3D objects and somehow people end up saying that they are numerically equivalent or no conversion is possible.

The correct answer is concentricity is one half of the runout value. Don’t believe me, here’s how George Schuetz of Mahr Federal Inc. explains it in his paper “TIR Versus Concentricity for Coaxiality“.

Simply put, and ignoring any error in form or alignment, the TIR check bases its coaxiality reading on diameters, while the concentricity check calculates radii.

See, it’s diameter versus radius, one half. Still don’t believe it, see if this description makes more sense to you.

Although it is never written this way, concentricity is a bilateral measurement (+/-). Think about it, a shaft and attached disc centered at the origin with a concentricity error on the disc of +1 unit. When you rotate the shaft 180° the error is now -1 unit. However TIR is always a unilateral measurement, so the +/-1 becomes +2/-0.

Still not grokking this, then look at this 2D graphical representation (click image for full size).


Hopefully this clears up the confusion, and you get the basic geometric rule. Concentricity error is exactly one half of the runout error. Still don’t believe it, then try it for yourself in your favorite CAD program or with a physical 2D model.

Warning about Green Laser Pointers

The NIST has just released a report and warning about a serious safety issue with some green laser pointers.

Late last year, the research team purchased three low-cost green laser pointers advertised to have a power output of 10 milliwatts (mW). Measurements showed that one unit emitted dim green light but delivered infrared levels of nearly 20 mW, powerful enough to cause retinal damage to an individual before he or she is aware of the invisible light.

NIST’s researchers have devised a simple test that you can do yourself to make sure your green laser pointer is safe (see the full report).

Happy World Metrology Day

WMD_2010_smallToday is the 4th annual World Metrology Day sponsored by the Bureau international des poids et mesures (BIPM, International Bureau of Weights and Measures) and Organisation Internationale de Métrologie Légale (OIML, International Organization of Legal Metrology).

From the press release:

As the world strives to move on from its recent financial problems, and as Governments work to regenerate economies, we shall find that science and technology are the engines of economic growth and prosperity. These, in turn, rely on being able to measure correctly and to refer measurements to the same international reference standards. A world without accurate measurement is a world where science, technology, trade and society can’t communicate and where error and uncertainty would reign supreme.

For an excellent introduction to the subject read, Metrology – In Short by the European Association of National Metrology Institutes (EURAMET).

Texas Instruments has reached the heights of stupidity

The latest from the EFF:

it is scandalous that the company continues to send its improper demands to other bloggers and hosting companies. In fact, TI has sent an identical take-down demand to Mr. Smith’s university complaining about the same OS keys having been posted on our client’s student webpage, and demanding that the school take the materials down from that URL.

TI’s abuse of copyright law is disgusting, I’m starting to think I should set up a boycott Texas Instruments website. They clearly have no clue, are very likely breaking the law and obviously have nothing but contempt for their customers. In the meantime my personal boycott remains in effect, no new components, assemblies or other products of any kind from TI will be used in my work or home. I strongly encourage everyone else to boycott TI as well because what they are doing is far worse than the RIAA or MPAA. While I dislike the tactics of the RIAA and MPAA at least they are operating legally, whereas what TI is doing is almost certainly illegal.

EFF sends notice to Texas Instruments

As I mentioned before I am currently boycotting Texas Instruments because of what to me is behavior worse than the RIAA and MPAA. They are using fear of copyright law to suppress legal actions by customers when there is no copyright infringement. The EFF has sent a warning letter to TI that explains the situation clearly. I am glad that the EFF has taken on the defense of the people abused by TI. I will continue to boycott TI until they publicly apologize for their egregious actions.

Designers Please Boycott Texas Instruments

I’m boycotting Texas Instruments for all new designs I create until they pull their heads out of their butts and apologize to their customers for their stupid anti-consumer actions. Linear Technology, National Semiconductor and ON Semiconductor are now my preferred analog and power chip suppliers and I’ll go with Microchip, Zilog, Intel and Freescale Semiconductor for my microcontroller needs. I strongly encourage all other electronic designers to join me in boycotting TI products until they wake up and treat their customers fairly.

Briefly, TI has sent DMCA takedown notices to TI calculator owners who posted the keys needed to change the OS on certain calculators. This is almost certainly legally wrong since the DMCA has been ruled by the courts to not apply in a similar situation (Lexmark v. Static Controls). While TI has a lame excuse about keeping the calculators trustworthy it is ridiculous because they used weak fairly easily breakable encryption. If TI truly feels they need to keep users locked out, they need to make an effort and use a real lock not a toy lock. Whatever they want to accomplish, legal threats against their customers is not the right thing to do.

Read more about this at the EFF.

American Meteorological Society Archives

The AMS has opened up their archives of 20th century articles to the public. Previously you had to go to a college library or pay $$ to see these articles, now we can get PDF’s for free!

This is a fantastic resource that covers all of their publications:
Journal of the Atmospheric Sciences
Journal of Applied Meteorology and Climatology
Journal of Physical Oceanography
Monthly Weather Review
Journal of Atmospheric and Oceanic Technology
Weather and Forecasting
Journal of Climate
Journal of Hydrometeorology
Bulletin of the American Meteorological Society
Meteorological Monographs
Earth Interactions

The archives search page is here: