Add 'best and worst mcu sdks post' (#153)

Author: franc0is

.gitignore

@@ -3,3 +3,4 @@
 _site
 vendor
 example/*/build
+.venv

_posts/2020-11-10-the-best-and-worst-mcu-sdks.md

@@ -0,0 +1,340 @@
+---
+title: The Best and Worst MCU SDKs
+description:
+  A detailed comparison of ARM Cortex-M Microcontroller SDKs and BSPs, from best
+  to worst.
+author: francois
+---
+
+In 2020, an MCU is much more than a hunk of silicon. Indeed, it comes with a
+whole ecosystem including a BSP, integrated third party libraries, tooling,
+field application support,  and more.
+
+As firmware engineers, we are often handed down an MCU selection as a fait
+accompli. Cost concerns, peripheral, or pinout requirements often take precedent
+over the SDK.
+
+Yet we are allowed to have an opinion. So here for you today is my first post in
+a new “comparing MCU SDKs” series.
+
+<!-- excerpt start -->
+
+In this post, I download SDKs for 10 popular Cortex-M4 microcontrollers, and
+evaluate how straightforward it is to get a simple example compiling. I include
+some step by step instructions to get started, a rating out of 10, and a few
+comments.
+
+<!-- excerpt end -->
+
+It goes without saying that this is an opinion based on my own very specific
+setup (MacOS, vim). Your mileage may vary!
+
+{% include newsletter.html %}
+
+{% include toc.html %}
+
+## What I’m looking for in a chip SDK
+
+My ideal chip SDK provides for a way to build and flash projects using tools of
+my choosing. This seems like a low bar, but few meet it. Here are things chip
+SDKs should **not** do.
+
+### Don’t choose my laptop OS for me!
+
+I left Windows behind when I worked at Sun Microsystems, and I have not looked
+back. Today, my daily driver is a MacBook Air.  Unfortunately, some chip vendors
+require that you use their Windows-based tools to setup and build your projects.
+Now that most compilers are cross-platform, there is no excuse for it.
+
+### Don’t chose my IDE for me!
+
+I’ve been using `vim` since college, and you can take it from my cold, dead
+hands. I love `vim`! I have it configured just saw. It’s lightweight, it’s fast,
+and modal editing is the way to work (prove me wrong!). So you’ll understand my
+dismay at the spate of Eclipse-based IDEs chip vendors want to foist upon me. I
+want nothing to do with their boated, Java environments.
+
+Instead of Eclipse-based IDE, I suggest SDKs provide Makefiles. `make` is the
+lowest common denominator build system, and is well supported by many tools.
+Bonus points for project files for IAR and Keil, since many of you like those
+tools.
+
+### Do include some examples
+
+If a picture is worth a thousand words, then a working code example is worth a
+million. Give me one example of each of the main use cases for your MCU. Bonus
+points if you give me an example for each peripheral.
+
+## Ten Popular Chip SDKs, Ranked
+
+### Nordic Semi nRF5-SDK - 10/10
+
+Nordic semiconductor’s line of Cortex-M4 MCUs includes the nRF52810, nRF52810,
+and nRF52840. All feature a 2.4GHz radio, which may deter you if all you want is
+an MCU.
+
+The nRF5-SDK (soon to be replaced by the equally excellent nRF-Connect-SDK), is
+in my view the best chip SDK out there.
+
+#### Why the rating
+
+* Cross-platform ✅
+* Supports armcc/Keil, IAR, and Makefiles ✅
+* Lots of bundled examples ✅
+* Single zip, no install needed ✅ 
+
+The nRF5 SDK does everything right. No registration, no install, no online
+configurator. It even is distributed under a BSD license!
+
+#### Compiling a Blinky example
+1. Download the nRF5 SDK from [nRF5 SDK downloads - nordicsemi.com](https://www.nordicsemi.com/Software-and-tools/Software/nRF5-SDK/Download#infotabs)
+2. Unzip the resulting `DeviceDownload.zip` file
+3. Unzip the SDK archive contained within. In my case that’s `nRF5SDK1702d674dde.zip`
+4. `cd` to the example you are interested in. Examples are contained within the `example` folder. In my case, `examples/peripheral/blinky/pca10040/blank`.
+5. `cd` to the build system folder of your choice, in my case `armgcc`
+6. Build the example, in my case by invoking `GNU_INSTALL_ROOT= make`
+
+This will generate a `bin`, `elf`, and `hex` file (among others) under `_build`.
+
+### Texas Instruments TivaWare - 9/10
+
+The Tiva C series is the latest entry in Texas Instruments’s line of Cortex-M
+microcontrollers.  I do not have a lot of experience with them, but they seem
+like solid microcontrollers with a broad range of peripherals (including USB).
+
+#### Why the rating
+
+* Cross-platform ✅
+* Supports armcc/Keil, IAR, and Makefiles ✅
+* Lots of bundled examples ✅
+* Single zip, no install needed ✅ 
+
+Like Nordic, Texas Instruments gets a lot right: single-zip download, multi-IDE
+support (including Makefiles), and lots of examples. I knocked off a point for
+the wonky `exe` file (see below) and the more complicated license.
+
+#### Compiling a Blinky example
+
+1. Download TiWare SDK from [SW-TM4C_2.2.0.295, TI.com](https://www.ti.com/tool/download/SW-TM4C)
+2. Rename the downloaded file from `exe` to `zip`
+3. Unzip it
+4. `cd` to the example you are interested in. In my case `examples/boards/dk-tm4c129x/blinky`.
+5. Run `make`, or open the IDE-specific folder of your choice.
+
+You’ll be left with an `axf` (aka an ELF) and a `bin`  file in the `gcc` folder.
+
+### NXP MCUXpresso - 9/10
+
+![](img/best-and-worst-mcu-sdks/E2992448-AC4D-4A31-9B86-E4806F729E51.png)
+
+NXP Kinetis traces its lineage to Motorola via Freescale. It is one of two
+Cortex-M lines from NXP (the other being the LPC).  Like many MCU vendors, NXP
+generates their SDK via a configurator and provide an Eclipse-based IDE, both
+under the “MCUXpresso” brand.
+
+#### Why the rating
+
+* Cross-platform ✅
+* Supports armcc/Keil, IAR, and Makefiles ✅
+* Lots of bundled examples ✅
+* Single zip, no install needed ⚠️
+
+I found the online MCUXpresso SDK builder a breeze to use. It is snappy,
+straightforward, and it keeps track of all your previously configured SDKs.
+Great job, NXP! The only downside of the tool is that it requires you to
+register on their website.
+
+I still have a preference for the monolithic SDK with all examples and targets
+in one place, but you could argue that this generates a smaller, more
+streamlined SDK.
+
+Best of all, the SDK uses `cmake` to generate build files. `cmake` is arguably
+more portable than `make`, as it is supported natively on Windows.
+
+#### Compiling a hello world example
+
+1. Go to the MCUXpresso SDK builder and create an account: [MCUXpresso SDK Builder](https://mcuxpresso.nxp.com/)
+2. Once logged in, click on “Select Board” in the sidebar
+3. Enter the name of your MCU. In my case, a Kinetic K21
+4. Click on “Build MCUXpresso SDK” on the right
+5. Name your project, select a toolchain, and some third party software like FreeRTOS or mbedTLS.
+6. Click on “Download SDK” at the bottom
+7. After a bit, the SDK will be ready for download
+8. Unzip the SDK
+9. `cd` to the example of your choice, in my case `boards/twrk21d50m/demo_apps/hello_world/`
+10. `cd` to build system folder, in my case `armgcc`
+11. Use the `build_debug.sh` build script and specify the`ARMGCC_DIR` environment variable:
+e.g. `ARMGCC_DIR=/usr/local/Cellar/arm-none-eabi-gcc/9-2019-q4-major sh build_debug.sh`
+
+This will generate an ELF file.
+
+### STM32 Cube - 8/10
+
+![](img/best-and-worst-mcu-sdks/6DA202F6-ED4E-4FFE-94B7-3A549D0F212F.png)
+
+ST has gone through multiple iterations of the SDK for the STM32 family of ICs.
+The latest is called STM32 Cube, which replaces the venerable Standard
+Peripheral Library. While Cube introduces a lot of complexity, it does so for a
+good reason: the STM32 family has grown to include 14 distinct series of MCUs
+from the very low power L0 to the very high performance H7.
+
+#### Why the rating
+
+* Cross-platform ✅
+* Supports armcc/Keil, IAR, and Makefiles ✅
+* Lots of bundled examples ✅
+* Single zip, no install needed ❌
+
+While Cube comes with support for many IDEs, and more examples than any other
+MCU SDK, it wraps it all in a clunky desktop app. I had a terrible time using
+STM32CubeMX: I had to install it on my laptop, it’s slow, it’s large, it’s
+clunky. I do not like it.
+
+STM32CubeMX generates a “project” directory based on your configuration. This
+means that you won’t have all the example code in one folder, and instead will
+need to generate different projects for different examples.
+
+Necessary complexity? Perhaps. But I miss the simpler Peripheral Library which
+came as a single archive.
+
+#### Compiling a Hello World example
+
+1. Download and install CubeMX: [STM32CubeMX - STM32Cube initialization code generator - STMicroelectronics](https://www.st.com/en/development-tools/stm32cubemx.html). Note: this requires registration on ST’s website
+
+3. Select “ACCESS TO MCU SELECTOR”
+4. Select the part you are using. In my case “STM32F429IE”
+5. In the Configuration view, click on the “Project Manager” tab
+6. Enter a project name, a path, and select a toolchain. In my case “Makefile”
+7. Click on “Generate Code” at the top right
+8. `cd` to the generated project directory
+9. Compile the project with your build system. In my case with `make`.
+
+###  Atmel START for SAMD - 7/10
+
+![](img/best-and-worst-mcu-sdks/83E37D9A-5975-4815-8937-437DA8675C0D.png)
+
+Recently acquired by Microchip, Atmel has been making SAM-family MCUs for a long
+time. The SAMD21 is well liked in hobbyist circles and is featured in several
+Arduino and Adafruit designs. Atmel’s peripheral library, AXF, went through a
+similar transformation to ST’s: it went from a single zip archive to a
+configurator.
+
+#### Why the rating
+
+* Cross-platform ✅
+* Supports armcc/Keil, IAR, and Makefiles ✅
+* Lots of bundled examples ✅
+* Single zip, no install needed ❌
+
+Atmel’s configurator is web based, and a tad more ergonomic than ST’s. However,
+the resulting Makefiles are much worse and even feature a bug (I had to fix OS
+detection).
+
+#### Compiling a hello world example
+
+1. Go to start.atmel.com
+2. Click on “Create New Project”
+3. Select your MCU. In my case a SAMD51 Chip.
+4. Click on “Export Project” at the top right
+5. Give it a name, and tick the check-box for your IDE (for me: Makefile)
+6. Click on “Download Pack”
+7. Rename resulting file from `.azip` to `.zip`
+8. Extract it
+9. `cd` to into IDE folder, in my case `gcc`
+10. Fix Makefile OS detection:
+    ```diff
+    @@ -22,7 +22,7 @@ else
+                    MK_DIR = mkdir -p
+            endif
+    
+    +       ifeq ($(shell uname | cut -d _ -f 1), Darwin)
+    -       ifeq ($(shell uname | cut -d _ -f 1), DARWIN)
+                    MK_DIR = mkdir -p
+            endif
+     endif
+    ```
+11. Run `make`
+
+### Silabs Simplicy Studio - 5/10
+
+![](img/best-and-worst-mcu-sdks/3F4AD307-656B-4664-B988-4F5A301BD771.png)
+
+Silabs Cortex-M MCU come from its acquisition of Energy Micro who was famous for
+the very low power consumption of their MCUs. Silabs now makes a range of
+Cortex-M based MCUs, some with 2.4GHz radios.
+
+Like many of the vendors in the lower half of this list, Silabs distributes
+their SDK alongside an Eclipse-based IDE. In their case they call it “Simplicity
+Studio”. While Simplicity is the best of those IDEs, it does leaves those of us
+who do not love Eclipse with few solutions. Here, I chose to use Eclipse to
+generate Makefiles.
+
+#### Why the rating
+
+* Cross-platform ✅
+* Supports armcc/Keil, IAR, and Makefiles ❌ (only IAR and GCC are supported by simplicity studio)
+* Lots of bundled examples ✅
+* Single zip, no install needed ❌
+
+Simplicity studio is huge (~1GB), slow, and complicated. Like all Eclipse-based
+IDEs, it generates poor Makefiles with hardcoded paths everywhere. 
+
+#### Step by step hello world example
+
+1. Register at silabs.com
+2. Download and install Simplicity Studio: [Simplicity Studio - Silicon Labs](https://www.silabs.com/products/development-tools/software/simplicity-studio)
+3. Setup SDKs on first run
+4. Click on File -> New -> Silicon Labs Project Wizard
+5. Under “Target Device”, select your MCU
+6. Click “Next”
+7. Select “Empty C project”
+8. Click “Next”
+9. Give the project a name, and select “Copy contents” under “With project files”
+10. Once the project is created, build it with Project -> Build Project
+11. Use the generated makefiles in the project folder
+
+
+### Infineon XMC4000, Renesas RA4 3/10
+
+Infineon and Renesas MCUs are popular for industrial applications and in the
+automative industry. In both cases, the standard setup is a Windows executable
+which installs an eclipse-based IDE.
+
+All is not lost however, as they also provide a peripheral library which can be downloaded standalone.:
+* Infineon calls theirs XMC Lib: http://dave.infineon.com/Libraries/XMCLib/XMC_Peripheral_Library_v2.1.24.zip
+* Renesas has the “Example Project Bundle”: [Download Detail Page, Renesas Electronics](https://www.renesas.com/us/en/software/D6004702.html)
+
+Unfortunately, neither of them offers Makefiles, so this is where my
+investigation ended. I did give them a few points for offering IAR and Keil.
+
+#### Why the rating
+
+* Cross-platform ❌
+* Supports armcc/Keil, IAR, and Makefiles ⚠️ (only IAR and GCC are supported by simplicity studio)
+* Lots of bundled examples ✅
+* Single zip, no install needed ❌
+
+### Cypress PSoC6, Maxim DARWIN 0/10
+Cypress and Maxim both make interesting chips: the former has a popular family
+of BLE MCUs under its PSoC brand, the latter makes MCUs with very large flash or
+RAM which can be put to good use.
+
+Unfortunately, I could not get anywhere with either. It seems PSoC creator is
+required to setup a PSoC6 project, but the app is windows-only.  Meanwhile all I
+could find from Maxim is a Windows installer for the “ARM Cortex toolchain.
+
+## Conclusion
+
+I hope you came away from this post with a better understanding of the different
+setup steps required for different MCU SDKs.
+
+You will note that I only looked at setup in this post. In the future, I intend
+to compare APIs, ecosystem, and tools.
+
+Do you have a favorite MCU SDK? We'd love to hear about it in the comments!
+
+<!-- Interrupt Keep START -->
+{% include newsletter.html %}
+
+{% include submit-pr.html %}
+<!-- Interrupt Keep END -->