I will show you the world without STM32
EFO Company restarts the site myMCU.ru - a portal for parametric search for microcontrollers and related solutions.
We have carefully studied the range of leading manufacturers of microcontrollers and made a single database of chips, debugging boards and software development tools. Today we will talk about how the site was created and what problems had to be solved in order to combine a variety of controllers into a single database for search and save detailed descriptions for each chip.
The article will be interesting first of all to developers of embedded systems - it will be about the problems of choosing hardware platforms, and not about ideal web interfaces and this is your usability.
')
Parametric search for such complex products as microcontrollers is a very useful thing. This is probably obvious to everyone.
Each manufacturer of microcontrollers in one form or another offers a parametric search, sometimes it works better, sometimes worse. Some Russian-language resources have a search system on the combined bases of crystals, but their main problem remains the poor quality of the controller base itself. Data from the documentation is collected semi-automatically, often containing errors and empty fields.
We set ourselves the goal to make not the most complete, but the most detailed and reliable system for the selection of microcontrollers.
Even if no user finds the resulting site useful, our work is not done in vain - we regularly receive requests from developers who start with the words " I need a microcontroller, which .. " and now we answer much faster.
So, our task was:
The result was not perfect, but quite decent. You can get to know him on your own, but for now, Iāll talk about some of the difficulties that we encountered when creating a site.
Imagine you have several dozen parameters of microcircuits and several hundreds of dissimilar datasheets. Gradually filling out a giant table of characteristics of microcircuits, you begin to understand that there are a huge number of almost-identical peripheral blocks, which are called differently.
Common bus interface IĀ²C.
Some manufacturers, such as Atmel, call the corresponding peripheral unit of the controller not IĀ²C, but TWI. Why? Because once IĀ²C was a registered Philips trademark and Atmel began using a different name. There are no difficulties with licensing the name IĀ²C for more than 10 years, but the name TWI has firmly established itself in the documentation for Atmel microcontrollers and is still used today.
There is another similar bus interface - SMBus. In fact, this is the same IĀ²C, but at 3.3 V.
It makes no sense to carry TWI or SMBus as a separate parameter of the chip, therefore we consider the corresponding peripheral modules to be identical and simply summarize. Thus, on the myMCU site, instead of āNumber of IĀ²C interfacesā, the sign āNumber of IĀ²C / TWI / SMBus interfacesā appears.
But not always similar problems are solved by simply combining similar peripheral blocks.
Banal serial interface UART. Fine.
First, we recall that, in addition to the UART, synchronous USART are often found. USART can work as a UART, but not vice versa, how best to present them on the site? While thinking about this issue, it is revealed that:
On the one hand, you need to reflect all these nuances in the descriptions of chips on the site. On the other hand, it is foolish to create separate attributes for a parametric search for the number of UART, USART, LeUART, PicoUART, and so on.
So there was an idea to duplicate such parameters for each microcontroller. In the base of microcircuits, one field serves only for parametric search and contains the total number of interfaces, and the neighboring field contains detailed information about what these interfaces actually represent. Information from the second field is displayed in the characteristics of the microcontroller on the site.
The same principle - the separation of data for search and data for display - we used in the description of other blocks.
So, SPI can be a separate SPI or QSPI block, and can also be implemented on a serial interface:
The approach turned out to be useful not only when describing communication interfaces, but also for input / output devices, an external memory connection interface, a hardware encryption unit, and many other chip parameters.
The presence of a LCD controller can also imply an interface for connecting a segment LCD and a TFT controller.
In the parametric search, only āyesā or ānoā is set for the presence of LCD, and in the resulting table in the LCD column both the type of supported indicators and the maximum number of segments or resolution will be indicated.
The presence of a controller of touch interfaces can mean anything at all. Choosing "yes" in the item Controller of touch interfaces you will receive microcontrollers that have:
I think the principle is already well understood and it is not necessary to list all the parameters of microcontrollers described in the same way.
We should also mention the search by case type. It is known that the same microcontrollers are often executed in different packages.
Consider an example. ATtiny24A is available in six packages:
The characteristics of the chip ATtiny24A on myMCU.ru, of course, displays a complete list of cases, but what to do with the search?
It is logical that the ATtiny24A chip should be included in the results of all queries containing at least one of the listed packages. The problem is that the list of unique cases is more than 200 different names. Making a huge list of checkboxes was not part of our plans, so the search options had to be reduced:
The first thing threw the size of the case.
Further, by a strong-willed decision, the number of legs was removed. Yes, this is some loss of information content, but otherwise the number of options could not be reduced to a reasonable size.
The last step was the grouping of cases - PDIP and CDIP united into a group of DIP; QFN, UDFN, DFN, MLF, VFQFN, LQFN, HTQFN, and others are merged into QFN, and so on.
As a result, there are 10 main groups of cases: BGA, CSP, DIP, PLCC, QFN, QFP, SOIC, SOP / SSOP, SOT and open-frame versions.
ATtiny24A is found for queries with a tick on DIP, SOIC, QFN or BGA.
In addition to universal controllers, the choice of which has a certain set of parameters, there are specialized circuits that have, in fact, the only main feature.
An example of such microcircuits are Wiznet microcircuits with a hardware-implemented TCP / IP stack, or FTDI controllers designed to control TFT displays.
In order for such a controller to be easily found on the website, a search function by a single parameter is provided - search by purpose.
We also tried to predict the popular requests of developers - the most budgetary controller, the most low-consuming controller, etc. To search by one of these parameters is Search by distinctive feature.
Most requests for parametric search on microcontrollers are popular and fairly simple requirements, which are covered by a large number of different chips. For example, we are looking for microcontrollers with a Cortex-M0 / M0 + core in a QFP package and at least three serial interfaces.
The result is 95 detailed microcontrollers from four different manufacturers. But who wants to peer into such a long table of results?
Therefore, we structured the results for each search - at first, the series of microcircuits are always displayed with an indication of their main characteristics.
Each series is disclosed in a large table with a detailed description of all microcontrollers belonging to the series and matching the user's request.
In this view, the data is read better, but choosing the one and only controller among the hundred chips is still not easy - the search parameters need to be refined.
Add some more conditions: at least 30 I / O lines, from 128 Kbytes of flash-memory and at least one USB Device interface.
As a result, only 14 microcontrollers are left, their characteristics can be studied in more detail in the drop-down tables.
The choice of a microcontroller is determined not only by the characteristics of a particular crystal, but also by the available development and debugging tools, training materials, and so on.
By clicking on any microcontroller presented in the table, you can find a menu with development tools, articles and news related to the selected controller.
This feature has been implemented using so-called tags - each board, program, article or news can be associated with one or more chips, a series of chips or with the entire range of the manufacturer. Indeed, most debug boards are designed to study a specific series of microcontrollers, branded IDEs usually fit all manufacturerās products, and, for example, IAR programmers are suitable for all ARM controllers regardless of the chip manufacturer.
Except in the recommendations for the selected microcontroller, all materials are available in single lists in the Development Tools , Articles and News menu.
We hope the resource will be useful for developers. Thanks for attention!
We have carefully studied the range of leading manufacturers of microcontrollers and made a single database of chips, debugging boards and software development tools. Today we will talk about how the site was created and what problems had to be solved in order to combine a variety of controllers into a single database for search and save detailed descriptions for each chip.
The article will be interesting first of all to developers of embedded systems - it will be about the problems of choosing hardware platforms, and not about ideal web interfaces and this is your usability.
')
Why was the site created?
Parametric search for such complex products as microcontrollers is a very useful thing. This is probably obvious to everyone.
Each manufacturer of microcontrollers in one form or another offers a parametric search, sometimes it works better, sometimes worse. Some Russian-language resources have a search system on the combined bases of crystals, but their main problem remains the poor quality of the controller base itself. Data from the documentation is collected semi-automatically, often containing errors and empty fields.
We set ourselves the goal to make not the most complete, but the most detailed and reliable system for the selection of microcontrollers.
Even if no user finds the resulting site useful, our work is not done in vain - we regularly receive requests from developers who start with the words " I need a microcontroller, which .. " and now we answer much faster.
So, our task was:
- Create a detailed and reliable "table", describing all the possible parameters of each chip.
- Organize a correct search for the maximum number of parameters.
- For each chip, select the appropriate debugging tools and provide the user with detailed descriptions of the respective boards, programs, etc.
- Collect in one place the articles, video reviews and other useful materials that we have accumulated, and form a list of resources for each selected chip by the user.
The result was not perfect, but quite decent. You can get to know him on your own, but for now, Iāll talk about some of the difficulties that we encountered when creating a site.
About data for search and for display
Imagine you have several dozen parameters of microcircuits and several hundreds of dissimilar datasheets. Gradually filling out a giant table of characteristics of microcircuits, you begin to understand that there are a huge number of almost-identical peripheral blocks, which are called differently.
Example # 1
Common bus interface IĀ²C.
Some manufacturers, such as Atmel, call the corresponding peripheral unit of the controller not IĀ²C, but TWI. Why? Because once IĀ²C was a registered Philips trademark and Atmel began using a different name. There are no difficulties with licensing the name IĀ²C for more than 10 years, but the name TWI has firmly established itself in the documentation for Atmel microcontrollers and is still used today.
There is another similar bus interface - SMBus. In fact, this is the same IĀ²C, but at 3.3 V.
It makes no sense to carry TWI or SMBus as a separate parameter of the chip, therefore we consider the corresponding peripheral modules to be identical and simply summarize. Thus, on the myMCU site, instead of āNumber of IĀ²C interfacesā, the sign āNumber of IĀ²C / TWI / SMBus interfacesā appears.
But not always similar problems are solved by simply combining similar peripheral blocks.
Example # 2
Banal serial interface UART. Fine.
First, we recall that, in addition to the UART, synchronous USART are often found. USART can work as a UART, but not vice versa, how best to present them on the site? While thinking about this issue, it is revealed that:
- Some Silicon Labs microcontrollers have low-speed, low-power UARTs called LEUART (Low Energy UART)
- Atmel microcontrollers have such interfaces too and are called PicoUART
- Some more Atmel controllers have serial interfaces Flexcom and SERCOM. Both units can operate in both UART mode and USART mode.
- Texas Instruments calls some serial interfaces with UART mode a mysterious abbreviation SCI
- Infineon launches ARM controllers with universal USIC units that can operate as UART, SPI, I2C, I2S or LIN
On the one hand, you need to reflect all these nuances in the descriptions of chips on the site. On the other hand, it is foolish to create separate attributes for a parametric search for the number of UART, USART, LeUART, PicoUART, and so on.
So there was an idea to duplicate such parameters for each microcontroller. In the base of microcircuits, one field serves only for parametric search and contains the total number of interfaces, and the neighboring field contains detailed information about what these interfaces actually represent. Information from the second field is displayed in the characteristics of the microcontroller on the site.
| To search by number of serial interfaces | To display search results on the site |
| 2 | 1 x USART + 1 x Low Energy UART |
| 2 | 1 x UART + 1 x USART |
| 2 | 2 x USART (on SERCOM blocks) |
| 2 | 2 x USIC (can work as UART, SPI, I2C, I2S, LIN) |
The same principle - the separation of data for search and data for display - we used in the description of other blocks.
So, SPI can be a separate SPI or QSPI block, and can also be implemented on a serial interface:
| To search by number of SPI interfaces | To display search results on the site |
| eight | 3 x SPI + 5 x SPI (via USART) |
| one | 1 x SPI (via QSPI) |
| 3 | 0 x SPI + 3 x SPI (via SERCOM) |
The approach turned out to be useful not only when describing communication interfaces, but also for input / output devices, an external memory connection interface, a hardware encryption unit, and many other chip parameters.
The presence of a LCD controller can also imply an interface for connecting a segment LCD and a TFT controller.
In the parametric search, only āyesā or ānoā is set for the presence of LCD, and in the resulting table in the LCD column both the type of supported indicators and the maximum number of segments or resolution will be indicated.
The presence of a controller of touch interfaces can mean anything at all. Choosing "yes" in the item Controller of touch interfaces you will receive microcontrollers that have:
- "Simple" capacitive input channels,
- PTC multifunctional touch input blocks (from Atmel MK),
- LEDTS units, designed not only for capacitive input, but also for controlling LED arrays (from Infineon MCs),
- Resistive touchscreen controllers and so on.
I think the principle is already well understood and it is not necessary to list all the parameters of microcontrollers described in the same way.
Example # 3
We should also mention the search by case type. It is known that the same microcontrollers are often executed in different packages.
Consider an example. ATtiny24A is available in six packages:
- PDIP-14,
- SOIC-14,
- MLF-20 (aka QFN-20) 4 x 4 x 0.8 mm
- VQFN-20 3 x 3 x 0.8 mm
- UFBGA-15 3 x 3 x 0.6 mm
The characteristics of the chip ATtiny24A on myMCU.ru, of course, displays a complete list of cases, but what to do with the search?
It is logical that the ATtiny24A chip should be included in the results of all queries containing at least one of the listed packages. The problem is that the list of unique cases is more than 200 different names. Making a huge list of checkboxes was not part of our plans, so the search options had to be reduced:
The first thing threw the size of the case.Further, by a strong-willed decision, the number of legs was removed. Yes, this is some loss of information content, but otherwise the number of options could not be reduced to a reasonable size.
The last step was the grouping of cases - PDIP and CDIP united into a group of DIP; QFN, UDFN, DFN, MLF, VFQFN, LQFN, HTQFN, and others are merged into QFN, and so on.
As a result, there are 10 main groups of cases: BGA, CSP, DIP, PLCC, QFN, QFP, SOIC, SOP / SSOP, SOT and open-frame versions.
ATtiny24A is found for queries with a tick on DIP, SOIC, QFN or BGA.
About specialized controllers
In addition to universal controllers, the choice of which has a certain set of parameters, there are specialized circuits that have, in fact, the only main feature.
An example of such microcircuits are Wiznet microcircuits with a hardware-implemented TCP / IP stack, or FTDI controllers designed to control TFT displays.
In order for such a controller to be easily found on the website, a search function by a single parameter is provided - search by purpose.
We also tried to predict the popular requests of developers - the most budgetary controller, the most low-consuming controller, etc. To search by one of these parameters is Search by distinctive feature.
About the presentation of chips on the site
Most requests for parametric search on microcontrollers are popular and fairly simple requirements, which are covered by a large number of different chips. For example, we are looking for microcontrollers with a Cortex-M0 / M0 + core in a QFP package and at least three serial interfaces.
The result is 95 detailed microcontrollers from four different manufacturers. But who wants to peer into such a long table of results?
Therefore, we structured the results for each search - at first, the series of microcircuits are always displayed with an indication of their main characteristics.
Each series is disclosed in a large table with a detailed description of all microcontrollers belonging to the series and matching the user's request.
In this view, the data is read better, but choosing the one and only controller among the hundred chips is still not easy - the search parameters need to be refined.
Add some more conditions: at least 30 I / O lines, from 128 Kbytes of flash-memory and at least one USB Device interface.
As a result, only 14 microcontrollers are left, their characteristics can be studied in more detail in the drop-down tables.
On the selection of materials "on the topic"
The choice of a microcontroller is determined not only by the characteristics of a particular crystal, but also by the available development and debugging tools, training materials, and so on.
By clicking on any microcontroller presented in the table, you can find a menu with development tools, articles and news related to the selected controller.
This feature has been implemented using so-called tags - each board, program, article or news can be associated with one or more chips, a series of chips or with the entire range of the manufacturer. Indeed, most debug boards are designed to study a specific series of microcontrollers, branded IDEs usually fit all manufacturerās products, and, for example, IAR programmers are suitable for all ARM controllers regardless of the chip manufacturer.
Except in the recommendations for the selected microcontroller, all materials are available in single lists in the Development Tools , Articles and News menu.
We hope the resource will be useful for developers. Thanks for attention!
Anticipating Comments
- Yes, on the site we place only those products that are supplied by the EFO. We do not claim to cover all the microcontroller solutions on the market, but we are ready to provide any technical support in the areas we are engaged in.
- The joke about Tutsi-dot-ru has been joking many times. No need again, really.
- The site is really almost no prices. I fully understand that price is also an important parameter when choosing a microcircuit, but myMCU is not an online store, so that's it.
Source: https://habr.com/ru/post/280145/
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