A Less Expensive Option for the Microcontroller Labs in Chapter 22 to 27
The Arduino Zero is a full-size Arduino board that contains both the SAMD21G18A microcontroller used on the SparkFun SAMD21 Mini board and a debugger compatible with Segger’s Embedded Studio development environment. If you are willing to deal with the inconvenience of connecting the Arduino Zero to the breadboard, it is a cheaper solution than the SAMD21 and J-Link to complete the microcontroller labs in LAoE. See How to Use an Arduino Zero in Place of the SparkFun SAMD21 in Chapters 22-27
Read MoreHere is a nice tutorial on inductors
We don’t spend a lot of time on inductors in Learning the Art of Electronics. See 3N.3. Real inductors tend have higher losses than real capacitors and also tend to be pretty large at the frequencies we use in the labs. Inductors come into their own at higher frequencies and in higher power circuits like power supplies.
One nice thing about inductors is that they are fairly easy to build — you just need a bunch of turns of wire (often around a core that increases the inductance per turn). If you would like to learn more about inductors, particularly how to build your own, here is a nicely done 13 minute video tutorial covering the basics.
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You can use almost any FPGA. But should you?
A reader wrote:
Will the Digilent Arty S7-50 FPGA board handle all of the WebFPGA labs in LAoE?
It could be overkill, but it’s on sale for 20% off and has some expansion capabilities that interest me. Plus, someone might get it for my birthday. 😀
My response:
There is no reason the Arty S7-50 should not work with all the labs except the ones in Chapter 18S which are Lattice iCE40 specific. We don’t use any fancy features of the FPGA, and the Spartan 7 has way more logic cells than the iCE40. You would, of course, have to use the Xilinx/AMD development tools. In addition, you would have to run wires from the Arty board to your breadboard.
Honestly, though, the magic of the WebFPGA is the simplified zero-install development environment. I can tell you when I first tried FPGA development I spent way more time struggling with the development tools than actually learning to use FPGAs. Xlinx was particularly annoying because there were multiple separate tools for each step of the process and when something did not work figuring out where the problem was was exhausting. (The developers of the tools also exposed EVERY parameter controlling their operation so finding the relevant one was very difficult.)
Since you are putting together your birthday request list, why not add the WebFPGA. (I just added a solder rework station to mine.) If you do decide to try the labs with the Arty board, let me know how it goes.
Read MoreThe Parts Lists now include parts organized by Lab
A reader suggested “[it] could be very good to have the list organized by lab directly.”
My response: A great suggestion. Both the Analog and Digital parts lists now include a list of parts organized by the lab they are used in. The HTML and Excel versions include a tab at the bottom of the page that selects between the parts organized by function and parts organized by lab. The PDF versions have the parts organized by lab as a extra page at the end of the documents.
Read MoreWhy not use the new built-in Arduino debugger and Arduino IDE for microcontroller development? (updated)
A reader pointed out that:
“The [the SAMD21 alternative] Arduino Zero not only comes with a preinstalled debug header, it comes with the debug hardware included. There is no additional debug hardware required at all. You can debug directly using the Arduino IDE.
Although more expensive than the other M0+ boards, it turns out cheaper in total as you don’t need the debug hardware.”
Update 2025-09-19: The discussion below concludes that the Arduino Zero used with the Arduino IDE is not a good substitute for the SparkFun SAMD21 Mini used with the J-Link debugger and Seeger’s Embedded Studio. However, if you are willing to deal with the inconvenience of connecting the Arduino Zero to the breadboard, the onboard debugger on the Arduino Zero works with Embedded Studio to do all the microcontroller labs in LAoE and it is a cheaper solution than using the SAMD21 and J-Link. See How to Use an Arduino Zero in Place of the SparkFun SAMD21 in Chapters 22-27
My response:
When we created the new microcontroller lessons in summer 2020 the Arduino debugger IDE was not available (except as a beta). We did try it out at the time but had trouble getting it to work. Even now, the Arduino IDE debugger is still somewhat limited – offering only high-level access (at the C code level) and tied to the Arduino ecosphere. It also is limited to a small number of boards without the hardware debugger (it was even fewer then). Also, we prefer (for pedological reasons) to be able to examine disassembled code and raw memory (see Figure 25S.3 in the book – reproduced below). At the time, the J-Link EDU Mini was only $13 (it has gone up significantly to $60 since then) so we did not see it as cost impediment. In our opinion, the Segger debugger is much more representative of modern development/debugging environments and we still feel it provides a better introduction to serious embedded systems development. It also interfaces well with the Segger embOS RTOS, which we believe is one of the two most important contributions in the second half of the new edition of LAoE (the other being finite state machine software and hardware design concepts).
Finally, we want readers to consider a microcontroller just another component in a circuit/product design. The traditional Arduino footprint of the Arduino Zero is not well suited to breadboarding. (See image below.) We only considered breadboard compatible microcontroller boards in developing the book’s embedded systems labs; however, I did include the Arduino Zero in the list of alternatives microcontroller boards in Chapter 22O. See https://laoe.link/LAoE_Chapter_22O.pdf, Section 22O.1.2.2, where we also note that the debug header is included (but it may no longer be populated based on the current images on the Arduino store web site).
That said, our undergraduate course used the Arduino environment because it was an easy and fast way to learn embedded systems. The purpose of this book was to go beyond that into professional development tools, hence the switch to the Segger tool chain.
We did recently try the internal Atmel Embedded Debugger (EDBG) hardware on the Arduino Zero board with the Arduino IDE (Version 2).
We were able to compile and test all the exercises in Lab 22L using the Arduino IDE and the Arduino Zero EDBG. You must remove or comment out the line
#include "samd21.h" // add to use CMSIS
in each program or you will get a compile error.
Nevertheless, the Arduino IDE supports CMSIS and all the code compiled and ran. The Arduino IDE runs the SAMD21 at full speed (48Mhz) so you have to slow down the Delay() routine (we changed the DELAYMUL value from 60 to 6000) to see the LED blink.
However, when we tried the Chapter 23 Labs, the programs would not compile because the internal Arduino support code already set the SysTick_Handler() to its own interrupt service routine.
C:\Users\David\AppData\Local\arduino\sketches\35BDD63E14BC04C0ACBA81EB7D1B6C1F/..\..\cores\arduino_samd_arduino_zero_edbg_7ab4d6888def7306e779da082f31f5d6\core.a(cortex_handlers.c.o): In function `SysTick_Handler': C:\Users\David\AppData\Local\Arduino15\packages\arduino\hardware\samd\1.8.14\cores\arduino/cortex_handlers.c:171: multiple definition of `SysTick_Handler' C:\Users\David\AppData\Local\arduino\sketches\35BDD63E14BC04C0ACBA81EB7D1B6C1F\sketch\JLink_Blink.ino.cpp.o:D:\Users\David\Documents\Arduino\JLink_Blink/JLink_Blink.ino:37: first defined here collect2.exe: error: ld returned 1 exit status exit status 1
Since the embedded system lessons in Learning the Art of Electronics program the SAMD12 “bare metal” (i.e. as though they have control of the entire microcontroller), the lessons in the book conflict with similar code in the Arduino environment. So, tThe Arduino Zero will not work with all the lessons when used in the Arduino IDE environment even though the Arduino IDE does support CMSIS. Looking at the Arduino init() function, Arduino enables all the SERCOM peripherals (SERCOM0 through SERCOM5), the Timer/Counters (TCC0 – TCC2 and TC3 – TC5), and the ADC and DAC, so the book code that tries to use these peripherals is likely to conflict with Arduino code.
Read MoreHow many do I buy of Parts List items without a quantity specified?
A reader asked “I uploaded the BOM [Bill of Materials, i.e., the Parts List] to DigiKey. For the parts where no quantity is specified, does that mean any amount between QTY 1 and QTY10 works? I see a considerable price drop when QTY10 are ordered, but I am not sure I need too many left-over parts considering that I am not planning to specialize in analog circuits (of course, that thought may change as I complete the labs).
My response: Many of the resistors and capacitors in the parts lists do not have a value specified in the “Qty Needed” column because we aren’t really sure how many you need and we expect you to buy a kit of resistors and capacitors, not purchase individual values. This is because in some cases it either does not matter much which value you use (for example, pull up resistors in the digital labs) and in others you choose the value based on what works in the circuit. For example, in the filter circuits and the LM555 oscillator, you can use [almost] any resistor and capacitor value that gives you the correct time constant. So a 1k resistor and 100nF capacitor should work as well as a 10k resistor and 10nF capacitor (both result in an R * C time constant of 100uS).
With only the exception where we have specified a quantity of a particular part, we assume you will purchase a kit of most popular values, which usually includes at least 10 of each value – more than enough for the experiments in the book. (The 100uF polymer capacitor used in the switching power supply is a special low ESR [Equivalent Series Resistance] part so it has a quantity but the rest of the capacitors are pretty much generic so do not have quantity specified — but you could use a generic part in the switcher lab and still get an understanding of how switching voltage regulators work, you would just lose some efficiency.) Most of these types of parts make no sense to buy in single quantities – they are too expensive – but a quantity purchase makes little sense for an individual user. A kit is much more economical than buying individual parts for individual use. OTOH, someone stocking a university lab may prefer to buy the values listed at the quantity pricing which is why we have specified particular part numbers – but in reality, there are dozens of other parts numbers for each of the parts we list that would work as well.
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