Continue with corrections to examples

examples/chapter02_03/readme.md

@@ -1,4 +1,5 @@
 # Example chapter02_03
+
 ## The LED program with timing
 
 This example implements the LED program (with timing) for the
@@ -12,7 +13,7 @@ Building the example can be done with GNUmake
 in the command batch or shell script.
 The results of the build will be stored in the `bin`
 directory. After successful build, files such as the HEX-file
-`led.hex` and othe name and map files can be found in `bin`.
+`led.hex` and the name and map files can be found in `bin`.
 
 ## With `GNUmake`
 
@@ -38,9 +39,9 @@ VC as well as Atmel Studio.
 
 In the LED program with timing, the blinking is controlled directly
 from the `main` subroutine of the program. The blinking
-frequency is approximately 1/2Hz, controlled by a timer dely.
+frequency is approximately 1/2Hz, controlled by a timer delay.
 The blinking loop can be found in the file `sys_start.cpp`.
-It is reproduced below within its contect in `main`.
+It is reproduced below within its context in `main`.
 Please note the MCAL initialization, which is essential
 for initializing clocks and interrupts. It is this layer
 that needs to be modified when porting to other microcontroller

examples/chapter02_03a/readme.md

@@ -1,4 +1,5 @@
 # Example chapter02_03a
+
 ## The LED program with cooperative multitasking scheduler
 
 This example implements the LED program with

examples/chapter02_06/readme.md

@@ -1,4 +1,5 @@
 # Example chapter02_06
+
 ## The Led Program (with template LED class)
 
 This example implements the LED program with a template
@@ -24,15 +25,15 @@ to capture the runtime of the port toggle.
 The toggle signal has a width of approximately
 $310~\text{ns}$, which agrees well with the claim in the book.
 
-![](./images/2020-01-12.pdf)
+![port signal measured on oscilloscope](./images/2020-01-12.png)
 
 The toggle signal having a width of approximately $310~\text{ns}$
 captured by a digital oscilloscope is shown.
 
 Manually measuring the toggle signal with a _scope_ might require laboratory skill,
-as shown in the next two pictures featuring a hand-help oscilloscope
+as shown in the next two pictures featuring a hand-held oscilloscope
 probe measurement on one of our self-made Arduino-like boards.
 
-![](./images/measurement.pdf)
+![hand-held measurement with oscilloscope](./images/measurement.png)
 
-![](./images/measurement2.pdf)
+![closer view of oscilloscope measurement](./images/measurement2-cropped.png)

examples/chapter03_02/readme.md

@@ -1,14 +1,15 @@
 # Example Chapter03_02
+
 ## Integer Types Having Fixed Widths and Prime Numbers
 
 <p align="center">
-    <a href="https://godbolt.org/z/dPbM7v4ff" alt="godbolt">
-        <img src="https://img.shields.io/badge/try%20it%20on-godbolt-green" /></a>
+    <a href="https://godbolt.org/z/dPbM7v4ff">
+        <img src="https://img.shields.io/badge/try%20it%20on-godbolt-green" alt="godbolt" /></a>
 </p>
 
 Example chapter03_02 focuses on integer types having fixed widths.
 The example gets into a fascinating calculation of prime numbers
-that is simultaneously intended to emphasize the usefullness
+that is simultaneously intended to emphasize the usefulness
 and portability of fixed-width integer types.
 
 ## Fixed-Width Integer Types
@@ -50,7 +51,7 @@ with the input `Prime[100]`.
 
 The example begins by querying the number of entries required
 in the sieve to calculate the prime 541. For this, a simple divergent
-asymptotic series approximation of the lograithmic integral function is used.
+asymptotic series approximation of the logarithmic integral function is used.
 Instead of 100, the approximation returns 108, which is
 adequately close to the desired limit and large enough.
 
@@ -70,17 +71,17 @@ The approximate runtime of each task call required for the
 entire sieve calculation of $100$ prime numbers is approximately $5\text{ms}$.
 
 A debug port, in this case `portd.3` is toggled high and low
-just prior to and after the call of the prime sieve cacle task.
-A straightofrward digital oscilloscope measurement provides
+just prior to and after the call of the prime sieve cycle task.
+A straightforward digital oscilloscope measurement provides
 a timing indication for the runtime of the prime sieve cycle task.
 
 A running hardware setup is shown in the picture below.
 
-![](./images/board03_02.jpg)
+![running hardware setup](./images/board03_02.jpg)
 
 The runtime of the prime sieve cycle task is depicted below.
 
-![](./images/scope03_02.jpg)
+![runtime curve on oscilloscope](./images/scope03_02.jpg)
 
 ## A PC-Based example
 
@@ -124,7 +125,7 @@ at this numerical point?
 
 Consider the following input.
 
-```
+```text
 N[(LogIntegral[10006721] - LogIntegral[2])/664999, 20]
 ```
 

examples/chapter04_04/readme.md

@@ -1,4 +1,5 @@
 # Example Chapter04_04
+
 ## LED Objects and Polymorphism
 
 Example chapter04_04 uses an intuitive LED class hierarchy
@@ -109,7 +110,7 @@ as shown in the following table.
 | LED4       | port expander pin `GPA2`    | port toggle high/low, SPI software drive, $750~\Omega$   |
 
 In this example, we use ports from both the microcontroller as well
-as an external port expander chip. Hardware adressing is used
+as an external port expander chip. Hardware addressing is used
 on the port expander chip. The port expander address is
 hard-wired to the value 7 via connecting each of the three
 pins `A0` ... `A2` to $+{5}~\text{V}$.
@@ -134,4 +135,4 @@ The connections of the port expander chip are tabulated below.
 
 The hardware setup is pictured in the image below.
 
-![](./images/board4.jpg)
+![hardware setup](./images/board4.jpg)

examples/chapter04_04a/readme.md

@@ -1,4 +1,5 @@
 # Example Chapter04_04a
+
 ## LED Objects and Polymorphism via References
 
 Example chapter04_04a implements the same basic functionality

examples/chapter06_01/readme.md

@@ -1,9 +1,10 @@
 # Example Chapter06_01
+
 ## A CRC Benchmark
 
 <p align="center">
-    <a href="https://godbolt.org/z/ssTK8TjWj" alt="godbolt">
-        <img src="https://img.shields.io/badge/try%20it%20on-godbolt-green" /></a>
+    <a href="https://godbolt.org/z/ssTK8TjWj">
+        <img src="https://img.shields.io/badge/try%20it%20on-godbolt-green" alt="godbolt" /></a>
 </p>
 
 Example chapter06_01 illustrates certain optimization
@@ -73,8 +74,7 @@ std::uint32_t crc32_mpeg2(input_iterator first,
 ## Application Description
 
 One of the standard tests of a CRC is to compute the checksum
-of the digits
-<img src="https://render.githubusercontent.com/render/math?math=1{\ldots}9">.
+of the digits $1 \ldots 9$.
 Please note here that the digits are not decimal values.
 They are the ASCII representations instead. In other words,
 the standard CRC test computes the checksum of a byte array such as
@@ -101,7 +101,7 @@ of the the expected result.
 The benchmark port pin `portd.3` is toggled high
 prior to the CRC calculation and low following the calculation.
 This provides a time pulse that can easily be measured
-on the oscilloscpoe. For the 8-bit target, expect
+on the oscilloscope. For the 8-bit target, expect
 a CRC runtime of approximately $300~{\mu}\text{s}$.
 
 The benchmark port definition can be located in the file

examples/chapter06_14/readme.md

@@ -1,4 +1,5 @@
 # Example Chapter06_14
+
 ## A CRC Benchmark with ROM-based Table and Data
 
 Example chapter06_14 has essentially the same functionality
@@ -39,13 +40,13 @@ The partial image of a memory map file from example chapter06_14 for
 the 8-bit target shows us that the data objects mentioned above have,
 in fact, been _ROM_'ed.
 
-![](./images/romdata.jpg)
+![snippet from map file](./images/romdata.jpg)
 
 The objects in the map-snippet above are in ROM.
 
 ## Application Description
 
 The same standard CRC checksum and verification
 is carried out in the `app::benchmark::task_func`
-function. Slight sylistic differences between the algorithms in
+function. Slight stylistic differences between the algorithms in
 example06_01 and example06_14 reflect no functional change.