Search MCUs with specific connectivity options  - Page 1
Forum section: electronics / general

author: BBBbbb
author_rank: Unknown
timestamp: May 14, 2018, 02:19:24 pm
content: I tried to search for MCUs on distributor sites (Mouser, Digikey, Farnell,...) with specific connectivity options, but I can not select only the support for the specific protocols I'm interested in, and then get the list of all the MCUs regardless of other connectivity options they have.For example if I'm interested in IIC+SPI+USB, I would have to select every single variant that has these 3 among others in the "filter" list, and there are way too many of them. I failed to find an option where I can select these 3 and list out all variants containing them.TI has this option, but that limits me to them only, and I do like other filtering options big distributors offer and want to be able to consider all manufacturers.Either I overlooked some option or they simply don't offer it, although I find this option as a quite logical one.Any advice is welcomed!

author: jnz
author_rank: Frequent Contributor
timestamp: May 14, 2018, 03:40:44 pm
content: It's been my experience that sorting through chips at the distributor level is not going to give you reliable results. When I do this, I find the chip mfgs that I might buy from (STM32 in any volume, Renesas in only high volume, etc) and search their sites.So if I was looking for a 64 pin hand solderable part with 2x CAN modules, I'd go to microchip/atmel, stm32, nxp, etc etc site directly and using the filters there.

author: BBBbbb
author_rank: Unknown
timestamp: May 14, 2018, 11:20:29 pm
content: Quote from: jnz on May 14, 2018, 03:40:44 pmOne reason for distributor sites is you get an immediate overview across different manufacturers at once (time saving). Another, more important, is that I use stock/availability on those site as an indication of current and future availability of that part.I spent like several minutes clicking all variants that included desired connectivity options, only to find out I'm not even halfway down the scroll bar.Seems strange they don't have these options separate IMO.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: May 14, 2018, 11:26:00 pm
content: Download an Excel table from Digi-key, then use spreadsheet formulas and filters to extract and find what you need.

author: jnz
author_rank: Frequent Contributor
timestamp: May 14, 2018, 11:59:00 pm
content: Quote from: BBBbbb on May 14, 2018, 11:20:29 pmI'm still sticking with my advice to find what you need on the mfg's site first. Each MFG can't even be bothered to list correctly, I don't trust a distributor to do it for everyone.And part of the issue you are having is there isn't a clear separation in hardware sometimes, the SPI peripheral may double as an I2C for example. Some are entirely reprogrammable like the PSoC series that give you blocks that can be SPI or UART. So they can't say it has 3 blocks AND 3x UART 3x SPI 3x I2C, but does have a combo of those - compared to an STM32 that does have 3x SPI and 3x UART it's not exactly an apples comparison.

author: JPortici
author_rank: Super Contributor
timestamp: May 15, 2018, 05:27:19 am
content: Unfortunately you'll have to go to to each manufacturer website and search there.And double check with the datasheet because they could have made a mistake when loading the data to the database, or because there may be subtle caveats like MSSP/SERIAL BLOCK being I2C/SPI/UART/.. in the same peripheral, or not being able to use CAN and USB at the same time.I would also love to have a unified database.. possibly with prices because i start checking out a part, oh cool it has everything i'm looking for, then i search for price and availability..

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 15, 2018, 04:24:50 pm
content: True but that's part of an engineer's job... often the most crucial part actually. Finding the right parts for a given project. Doing technology watch.Hopefully people wishing most of their work were automated won't complain when their job is not needed anymore.That aside (with some humor), I agree most distributors' websites are more or less anemic when it comes to filtering parts in general. That leaves a great margin of progression.But one thing you have to consider is that component selection, especially somewhat "critical" parts such as MCUs, usually can't be done on a features or pricing basis only. There are a lot of other things to consider, such as the vendor itself (you may have business reasons to select one or reject one), the development tools, the quality of technical support, the long-term availability, etc.

author: JPortici
author_rank: Super Contributor
timestamp: May 15, 2018, 05:01:20 pm
content: Quote from: SiliconWizard on May 15, 2018, 04:24:50 pmyes but manufacturers and their websites should be of help, instead of standing in the way.for example, NXP part selector is garbage. It's mostly javascript so i have to go back and forth between pages. If i dare to press the middle button to open a link in a new tab i get javascript:void(0)And of course i can't always filter out parts because i want to look for a specific parameter which is not there, or the data in the selection is wrong so it keeps/removes the wrong parts. And there are many parts with wrong dataQuote from: SiliconWizard on May 15, 2018, 04:24:50 pmAgain, yes but price is an imporant factor, esp. when it's a big chunk of the BOMPart A and Part B satisfy the requirements. Part B has a couple of hardware/software features that are nicer but not essential, can be easily worked around. Part B costs 2x. One can be tempted to go with part A

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 15, 2018, 05:08:25 pm
content: I must admit. Whereas a lack in filtering options/reliabilty on distributors' websites is annoying but sort of acceptable, it's a lot less when directly dealing with a vendor's website. That can actually be a reason not to work with a given vendor IMO. So there, you have it filtered (out). Next.I've always found NXP pretty awful in that area, and actually never considered any NXP part so far aside from trivial logic ICs (which they have a lot of).

author: nctnico
author_rank: Super Contributor
timestamp: May 15, 2018, 05:16:20 pm
content: IMHO NXP's website doesn't work any worse or better compared to other manufacturers. Just like other manufacturers you sometimes have to enable more columns to filter on.More on-topic. I'd try to stick to a single manufacturer/range unless you need something low cost for a high volume product (>million) otherwise the incompatibilities between various manufacturers make porting code between them way more expensive than the cost savings. The same goes for taking the time to learn the internals of many different microcontrollers. If you are not sure which manufacturer to use then buy a few evaluation boards and try to make some demo projects.Using distributor data to look/filter for parts is tricky because there usually are errors. Selecting a part is often an iterative process where you select a part from a manufacturer, see if it is available from a distributor and if not go back to selecting a part from a manufacturer.

author: BBBbbb
author_rank: Unknown
timestamp: May 16, 2018, 09:34:19 am
content: I agree, even with the remarks I mentioned, distributors still provide visually better overview that manufacturers IMO, and I understand the difficulties of unifying a connectivity options across different manufacturers, especially with the likes of Cypress having some type of modularity and a bunch of ™ names, but I just thought somebody did go through all the trouble to provide some not so strict "guideline" filtering.I'm here talking about hobby/small project stuff. If I was looking into choosing an MCU for future manufacturing, spending a few days (even weeks) for choosing would be acceptable, and in those situations I would be looking into the availability of the manufacturer for support. But If I might end up buying few 10s of these MCUs, all I want to know is can I buy and program them on a budget and will they be available for order without weeks of lead time (and this I usually estimate by the current stock at both Digikey and Mouser)

author: Gibson486
author_rank: Frequent Contributor
timestamp: May 16, 2018, 02:33:18 pm
content: Quote from: jnz on May 14, 2018, 11:59:00 pmI agree. Digikey also does this stupid thing where they rely on manufacturers to name the functions that you filter with. For example, on one chip, it could be called i2c, on another, it will simply be called 2 wire serial, when, in the datasheet, it says i2c.

author: NorthGuy
author_rank: Super Contributor
timestamp: May 16, 2018, 05:32:23 pm
content: Quote from: Gibson486 on May 16, 2018, 02:33:18 pmDigiKey makes mistakes. It's very hard not to. If you search for something extreme, you often find things which are too good to be true, but then it happens to be some sort of typo.I usually select things from my head - things I worked with before, or considered. If I try to find something totally new to me, searches get tough. Nobody ever put really important things into their parametric search tables ...

author: Bassman59
author_rank: Super Contributor
timestamp: May 17, 2018, 06:48:16 pm
content: Quote from: jnz on May 14, 2018, 11:59:00 pmSPI is sometimes called USART, and the USART can also implement I2S for digital audio, but if that capability isn't listed, you'll never know.Another annoyance: the column for USB often indicates "Yes" or "No." But what if I'm looking for High Speed USB? A lot of micros support only Full Speed but the only way to know is to RTFDS.

author: RobK_NL
author_rank: Frequent Contributor
timestamp: May 17, 2018, 07:38:51 pm
content: I tend to use Digikey's "search within results" box for this type of quest. Not ideal, but far better than manually selecting everything.Of the 67.761 embedded microcontrollers on offer, putting "I2C SPI USB" in the search box and selecting only 'in stock' and 'active' narrows it down to a mere 3.465