Write further tasks

8eb6f343 · Stefan Hackenberg · f69ae358 · 8eb6f343 · 8eb6f343 · 8eb6f343
Commit 8eb6f343 authored Sep 26, 2021 by Stefan Hackenberg
--- a/tasks/optional_coding_style.md
+++ b/tasks/optional_coding_style.md
+# Optional: Coding Style
+
+## Description
+
+If your code should have a professional look-and-feel it is important to follow a coding style.
+There are several tools helping you to avoid mistakes. Two great tools are Clang Format and Clang Tidy's readability-identifier-naming.
+
+### Clang Format
+
+With the help of clang format you can define a code formatting style. This includes line width, indentation style, alignments, ...
+It even is able to automatically format your code.
+
+Have a look at the [styling options](https://clang.llvm.org/docs/ClangFormatStyleOptions.html) and define your style.
+
+I personally like the following style:
+
+```clang-format
+BasedOnStyle: WebKit
+ColumnLimit: 120
+AlignAfterOpenBracket: AlwaysBreak
+AlignEscapedNewlines: DontAlign
+AllowAllArgumentsOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: Empty
+AllowShortFunctionsOnASingleLine: None
+BinPackArguments: false
+BinPackParameters: false
+BreakBeforeBinaryOperators: None
+BreakBeforeBraces: Allman
+MaxEmptyLinesToKeep: 2
+PointerAlignment: Right
+```
+
+### Clang Tidy readability-identifier-naming
+
+Clang Tidy has much more power than only observing identifier naming. But for now, let's focus on that option.
+
+If you prefer lower_case for function names and UPPER_CASE for global constants for instance you can configure:
+
+```
+Checks: '-*,readability-identifier-naming'
+CheckOptions:
+  - { key: readability-identifier-naming.FunctionCase, value: lower_case }
+  - { key: readability-identifier-naming.GlobalConstantCase,  value: UPPER_CASE }
+```
+
+### Integration in VSCode
+
+Both tools integrate perfectly in VSCode:
+- https://code.visualstudio.com/docs/cpp/cpp-ide#_code-formatting
+- https://marketplace.visualstudio.com/items?itemName=notskm.clang-tidy
+
+To configure your project for Clang Format create a file `.clang-format` in the project's root and enter your configuration options.
+
+Enabling Clang Tidy works similar.
+
+## References
+
+- Clang Format: https://clang.llvm.org/docs/ClangFormat.html
+- Clang Tidy readability-identifier-naming: https://clang.llvm.org/extra/clang-tidy/checks/readability-identifier-naming.html
--- a/tasks/optional_document_code.md
+++ b/tasks/optional_document_code.md
+# Optional: Document Code
+
+## Description
+
+Good documentation is a crucial for successful projects.
+
+Although C does not define a standard documentation process (like most of the modern programming languages).
+But there are several best practices:
+- Only English language.
+- Short header in each file explaining it's purpose. (And usually a copyright)
+- Structuring a file by separation of includes, defines, global, declarations, implementation
+- Header above each function explaining it's purpose, all parameter, and return values.
+
+### File scope
+
+Usually a new file is built from a template. Template we are using is:
+
+```c
+/**
+ * Purpose.
+ */
+
+//___includes_____________________________________________________________________
+
+
+//___defines______________________________________________________________________
+
+
+//___typedefs_____________________________________________________________________
+
+
+//___statics______________________________________________________________________
+
+
+//___implementation_______________________________________________________________
+```
+
+### Function scope
+
+The "standard" for documenting C code is given by the program [Doxygen](https://www.doxygen.nl/index.html).
+It parses code and it's comments and generates a browsable html documentation.
+How to make Doxygen compliant comments can be seen in the example below.
+
+## Example
+
+Consider this small unittest module equipped with documentation:
+
+```c
+/**
+ * Module containing unittests.
+ */
+
+//___includes_____________________________________________________________________
+
+#include <mbed.h>
+#include <unity.h>
+
+
+//___globals______________________________________________________________________
+
+/// A magic value
+const uint8_t MAGIC_VALUE = 42;
+
+
+//___implementation_______________________________________________________________
+
+/**
+ * Test equality of to unsigned values.
+ *
+ * @param[in] value Value to be tested
+ */
+void test_equality(uint8_t value)
+{
+    TEST_ASSERT_EQUAL(MAGIC_VALUE, value);
+}
+
+/**
+ * Main entry point for unittest framework.
+ *
+ * @return Exit status
+ */
+int main(void)
+{
+    UNITY_BEGIN();
+    test_a_well_known_truth(7);
+    UNITY_END();
+    return 0;
+}
+```
+
+## References
+
+- Documenting the code: https://www.doxygen.nl/manual/docblocks.html
+- Special commands: https://www.doxygen.nl/manual/commands.html
--- a/tasks/optional_read_image_snippet_ansi.md
+++ b/tasks/optional_read_image_snippet_ansi.md
+# Optional: Read Image Snippet ANSI
+
+## Description
+
+Image snippets can be "displayed" on the terminal console using the following endpoint:
+
+| **/getsnippet_ansi** |                               |
+| :--                  | :--                           |
+| <-                   | `<NFC_UID: 7> <INDEX: 1>`     |
+| ->                   | `<IMAGE_SNIPPET_ANSI: ~1000>` |
+
+The returned data is directly printable on the terminal:
+
+```c
+printf(response->get_body_as_string().c_str());
+```
+
+## Prerequisites
+
+### Tasks done
+
+- [Test HTTP Request](./test_http_request.md)
+- [Read NFC UID](./read_nfc_uid.md)
+
+### State
+
+- WiFi instance must be connected.
+
+## Acceptance criteria
+
+- Image snippet visible on terminal.
+
+## References
+
+- HTTP Request header file: https://gitlab.elektrotechnik.hs-augsburg.de/hackenbs/mbed-http/-/blob/main/src/https_request.h
+- HTTP Response header file: https://gitlab.elektrotechnik.hs-augsburg.de/hackenbs/mbed-http/-/blob/main/src/http_response.h
+
+## Further information
+
+- ANSI escape code colors: https://en.wikipedia.org/wiki/ANSI_escape_code#Colors
+- Python climage: https://github.com/pnappa/CLImage
--- a/tasks/order.dot
+++ b/tasks/order.dot
+// dot -Tsvg order.dot -o order.svg
 digraph G {
    graph [fontname = "helvetica"];
    node [fontname = "helvetica"];
    edge [fontname = "helvetica"];

-    install_vscode_and_platformio [URL="install_vscode_and_platformio.md"];
-    clone_repository_smi21 [URL="clone_repository_smi21.md"];
-    compile_smi21 [URL="compile_smi21.md"];
-    connect_psoc6_with_rc522 [URL="connect_psoc6_with_rc522.md"];
-    install_platform_cypress_psoc6 [URL="install_platform_cypress_psoc6.md"];
-    optional_install_further_extensions [URL="optional_install_further_extensions.md"];
-    test_connection_psoc6_with_rc522 [URL="test_connection_psoc6_with_rc522.md"];
-    test_http_request [URL="test_http_request.md"];
-    test_wifi_connection [URL="test_wifi_connection.md"];
-    upload_smi21 [URL="upload_smi21.md"];
-    write_first_test [URL="write_first_test.md"];
-    read_nfc_uid [URL="read_nfc_uid.md"];
-    read_nfc_hashtable [URL="read_nfc_hashtable.md"];
+    install_vscode_and_platformio
+    clone_repository_smi21
+    compile_smi21
+    connect_psoc6_with_rc522
+    install_platform_cypress_psoc6
+    optional_install_further_extensions
+    test_connection_psoc6_with_rc522
+    test_http_request
+    test_wifi_connection
+    upload_smi21
+    write_first_test
+    read_nfc_uid
+    read_nfc_hashtable
+    read_image_snippet
+    optional_read_image_snippet_ansi
+    optional_document_code
+    optional_coding_style

    install_platform_cypress_psoc6 -> compile_smi21;
    clone_repository_smi21 -> compile_smi21;
@@ -29,4 +34,8 @@ digraph G {
    install_vscode_and_platformio -> optional_install_further_extensions;
    test_connection_psoc6_with_rc522 -> read_nfc_uid;
    read_nfc_uid -> read_nfc_hashtable;
+    test_http_request -> read_image_snippet
+    read_nfc_uid -> read_image_snippet
+    test_http_request -> optional_read_image_snippet_ansi
+    read_nfc_uid -> optional_read_image_snippet_ansi
 }
--- a/tasks/order.svg
+++ b/tasks/order.svg
@@ -4,199 +4,208 @@
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 <title>test_http_request</title>
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+<!-- read_image_snippet -->
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+<title>read_image_snippet</title>
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--- a/tasks/read_image_snippet.md
+++ b/tasks/read_image_snippet.md
+# Read Image Snippet
+
+## Description
+
+Image snippets are stored on the server. They can be requested at the following endpoint:
+
+| **/getsnippet** |                                   |
+| :--             | :--                               |
+| <-              | `<NFC_UID: 7> <INDEX: 1>`         |
+| ->              | `<IMAGE_SNIPPET_JPG: 800 - 4500>` |
+
+## Prerequisites
+
+### Tasks done
+
+- [Test HTTP Request](./test_http_request.md)
+- [Read NFC UID](./read_nfc_uid.md)
+
+### State
+
+- WiFi instance must be connected.
+
+## Acceptance criteria
+
+- Image snippet can be read, i.e.
+  - Server returns status code 200
+  - Between 800 - 4500 bytes binary data of snippet present in response body.
+  - Received image snippet visible on server screen.
+- Positive test written.
+- Negative test written.
+
+## References
+
+- HTTP Request header file: https://gitlab.elektrotechnik.hs-augsburg.de/hackenbs/mbed-http/-/blob/main/src/https_request.h
+- HTTP Response header file: https://gitlab.elektrotechnik.hs-augsburg.de/hackenbs/mbed-http/-/blob/main/src/http_response.h
+
+## Hints
+
+- Explanation of the notation for the endpoint:
+  - "**/getsnippet**": The URL after the host address.
+  - "<-": This data needs to be sent to the server.
+  - "->": This data is returned by the server.
+  - "`<NFC_UID: 7>`": 7 bytes of binary data containing the NFC UID.
+
+- There is already a define for the number of bytes of a tag's UID in `smi.h`:
+
+  ```c
+  /// Length nfc tag identifier
+  #define SMI_TAGID_LENGTH 7
+  ```
+
+- Copying binary in data in C need a call to `memcpy`:
+
+  ```c
+  uint8_t buffer[SMI_TAGID_LENGTH + 1];
+  memcpy(buffer, nfc.uid.uidByte, SMI_TAGID_LENGTH);
+  ```
--- a/tasks/read_nfc_hashtable.md
+++ b/tasks/read_nfc_hashtable.md
@@ -30,7 +30,7 @@ Note that always a buffer of 18 bytes need to be passed but only the first 4 byt

 ### Hashtable

-