MCU selection tool

[davenadler]

I'm struggling to choose an MCU for a new project/product.
I have a list of how many I2C, UART, USB, SHCD etc. I need,
but find no tool on NXP's web site to show me the available
MCUs (and particular parts and packages) meeting the requirements.
Where is this information?
The "selector" tool on NXP web site is utterly and absolutely useless.
Thanks in advance for any pointers,
Best Regards, Dave

PS: Here's an example of a USABLE tool from TI:
https://www.ti.com/microcontrollers/other-mcus/products.html#p887=ARM%20Cortex-M4F;ARM-Cortex-M3 

[mjbcswitzerland]

Hello Dave

Could you list what you need since I have a header in the uTasker project that lists all of these details and filters out the parts that match.

With USB you need to specify whether you need FS or HS and whether crystal-less device is desired. For SDHC you need to specify whether it is a must or whether SPI mode would also be acceptable.

Regards

Mark
[uTasker project developer for Kinetis and i.MX RT]
Contact me by personal message or on the uTasker web site to discuss professional training, solutions to problems or rapid product development requirements

For professionals searching for faster, problem-free Kinetis and i.MX RT 10xx developments the uTasker project holds the key

[davenadler]

@mjbcswitzerland  - Here's the list...
I'll use crystal, FS USB is OK.
Thanks Mark!
Best Regards, Dave

MCU needs:

• USB 2.0 slave (FS OK, HS not required)

• I2C (ideally 2 channels which avoids need to reprogram sensor IDs, 3 channels better for OAT)

• SD card SDHC – could use SPI which is slower but probably OK

• ADC (low-res OK, for flap and maybe OAT)

• 3 UART

  • GPS

  • RS-485: requires UART 9-bit support, available in Kinetis and TM4C1290,
    not in many devices nRF52840 etc.

  • Bluetooth module (classic SPP)

• Nice only:

  • DAC, maybe drive analog meter

  • Bluetooth, but only if classic for SPP, replacing 1 UART above

[mjbcswitzerland]

Dave

There are a lot of parts (anything above K20 or KL20 would more or less do it) but for a new development I would look seriously at the K32L2A41 (or 32):
https://www.utasker.com/kinetis/FRDM-K32L2A4S.html
https://www.nxp.com/products/processors-and-microcontrollers/arm-microcontrollers/general-purpose-mc...

There are no KW parts (with BLE) with USB so a external Bluetooth module will be needed. Also this give much more flexibility in Bluetooth performance.

The K32L2A41 is one of the newest parts with crystal-less operation (for USB device) so you can run it from a single 32kHz crystal at up to 96MHz. It has the best power control features, being from the most modern ultra low power, high integrated family. 3 LPUARTs and 3 LPI2C and even DAC.

Although not necessarily needed, these are on-board and may come in handy:
- BOOTROM
- full featured RTC (with battery backup) and system registers that retain data
- EMVSIM
- CAU_V2 encryption accelerator
- Memory mapped divide and square root module
- FLEXIO
- Full-featured 8 channel DMA controller (whereas the majority of low power parts have a reduced feature version).

Lots of RAM (128k) and 256 or 512k Flash for adequate space to grow.
The newer parts are attractively priced [another important engineering parameter] ($1.50..$1.80) in quantity that compares favorably with one of the lower mid range K20s, like an older 72MHz K20DX128 which costs more like $3.30 and has less memory and less features.

This assumes you don't absolutely need SDHC since that forces you to a higher end K20 or beyond, which starts at more like $6.50 and excludes lower power parts. In fact you probably would be best to stick with a K64 that you already know in this case since they are not any more expensive.

Does this take your fancy or do you need max SDHC performance?

Regards

Mark

[davenadler]

Mark @mjbcswitzerland - Thanks very much! I was not aware of that part and had not found it because of NXP's lame pathetic web site. Looks like the 48-pin version meets all of our requirements, and half the cost (and board space) of the 100-pin K64F (my default choice). I did check with MCU configuration tool and was able to quickly find a set of pin assignments that exposed all our required features. With unacceptable NXP web site, I was unable to see if any LPC series parts meet our requirements.

Still need to review in detail a couple other vendor options like TI Also need to review if we could trim down requirements to use an ESP32 which would eliminate need for additional RF interface chip (ESP32 is used successfully by some of our colleagues, and it is extremely low cost).

Thanks again for the help!
Best Regards, Dave

[mjbcswitzerland]

Hi Dave

My IAR ARM version supports over 40 processor manufacturers, some of which have over 1000 processor types in their ARM portfolio - giving some >20'000 individual parts that could be chosen for a new application. Identifying the single most suitable one would take months of work and when the winner stands you will find that in the meantime another hundred new types have come on the market which should really be checked out to be sure too. Therefore practically the choice is an educated guess and it makes sense to try to use something that one already feels comfortable if possible to avoid potentially nasty surprises (with costs and delays) on the way. Also something that has good availability and guaranteed life time.

ESP32-S2 is what I have started using for Wifi and these parts are incredibly low price (it hardly costs $2 today to add Wifi to a product).
For Wifi +BLE, with USB too you should look at their new ESP32-S3 part: https://www.espressif.com/en/news/ESP32_S3?position=0&list=Ni799oJAfy46X5n7e4hiwsgquJxvkOQVs3iOY9bIz...
It is dual core so is suitable for writing applications in one that runs in parallel with the RF stacks in the other.
The thing that bothers me somewhat about ESP32 is that no sooner have you designed in a new part that they announce that it is no longer recommended for new designs.....it is a fast moving market and I hope that at least the availability remains stable.

Regards

Mark

[Alexis_A]

Hello @davenadler,

One of the MCU in the LPC family that matches the description is the LPC552x/LPC55S2x, the key points for this MCU are:

• Cortex-M33
• 8x Flexcomm module to emulate UART/SPI/I2C or I2S interfaces
• PLU to emulate analog logic 
• (LPC55s2x) Secure features as On-the-Fly decryption image, AES/SHA encryption, RNG. 
• ADC 16-bits 1Msamples/ps
• HS USB + PHY/ FS USB + PHY
• 2 DMA modules (22ch / 10 ch)

This misses the DAC and the BL classic module, so I think the suggestion from @mjbcswitzerland is a better option but if you look for an MCU with a higher performance this could be an option.

Best Regards,

Alexis Andalon

[davenadler]

@Alexis_A- I have an LPC55S28-EVK here, which we evaluated for another project. Unfortunately the DMA capabilities of the LPC55S28 were enormously inferior to the Kinetis series, and inadequate for that application. We used again the K64F and that project, which will be in production ~Q2. You might want to review the answers about that part I received on this forum - very discouraging.

We've used the K64F for:

• A specialized measurement tool for calibration and tuning of semiconductor fab production equipment (probably now in use where K64 are fabricated
• An experimental industrial measurement system now undergoing test at a major pharma company (helps with process control, for a new COVID-19 drug).
• The project mentioned above (industrial measurement tool to replace older generation tool already used by all major airframe and jet engine manufacturers).

We use the DMA subsystem to manage sequencing of internal DAC plus external ADC and control signals. Thus we can capture a hundreds of samples at high speed (and correlated with the DAC), without CPU involvement until the samples are sitting in RAM ready for processing. It is an important requirement...

Can you possibly put a real live human FAE in touch with me?
My contact info is on www.nadler.com - Boston area.

Thanks!
Best Regards, Dave

[myke_predko]

Hey @mjbcswitzerland 

Interesting choice.  I didn't know about these parts but you pulling them up actually reinforces the point @davenadler was making originally - there aren't any tools (like the TI tool Dave linked) that provides the ability to select these parts.  

I'm not sure about the quoted clock accuracy (+/-3%) but I'll have to look into it some more if I'm interested in using them for a product.  It should be noted that the "L2" parts are Cortex M0+ (which may be an issue becasue the M0 executes a lot fewer instructions per clock than the M4).  

Thank you for the pointer - something to keep in my hip pocket.  

myke

[myke_predko]

Hey @davenadler 

I'll be curious to see what @mjbcswitzerland will say but I would think that you're looking at a MK2x device becasue of the USB requirement - I've configured a circuit that's very close to what you have (except I use the DAC for .wav audio out) using the MK22FN but with an external BT module.  

Now, most BT modules have a 32bit ARM as the controller but I haven't found one that has a USB interface on it (although several probably meet your the ADC, DAC SPI, I2C and UART requirements).

myke

[davenadler]

@myke_predko- We've delivered some very successful products using K64F
Also LPC11C24 and earlier parts... I'm complaining about the web pages you cited!

Don't know how one gets an FAE assigned - vendors seem not to want to talk
unless one is a bazillion-unit customer. And we're a design firm who never orders
anything in volume (customers, or sometime manufacturing partners, do ordering).

GGrrrrr... Maybe we'll have to take a look at the TI parts - looks attractive!

[myke_predko]

@davenadler 

Go with the company you're working for to your local NXP office and explain what you are doing and why you need their help on new and existing products with expected yearly sales of $X Million dollars.  

Tell them that you have been a loyal NXP (and Freescale, I'm presuming from your email, before that) customer/designer and you would like to continue the relationship but the online support isn't adequate for your needs for your upcoming products.  You should get a reasonable response - note that you should emphasize that you only require an hour or so of their time.  

Good luck!

[myke_predko]

I hear you.  

It can be incredibly frustrating to not only select a part for a product but also appropriate development boards (Freedom and Tower) to get software work started while the boards are being designed.  

I've had the best luck with talking to my FAEs directly - if they're knowledgable they are as good as any tool.  If you don't have that, start with the high level descriptions (to get the absolutely necessary functionality, ie Ethernet, BT, motor control, etc.) and put your questions up on this forum.  

Just looking at the General Purpose MCU page, it is rather poor and really gives short shrift to Kinetis devices - you wouldn't be considered remiss if you missed Kinetis K Series MCUs (which is what we're talking about here) that gives you a high level understanding of the base functionality of eah family.  

Good luck!