Add more tasks and task graph

README.md

+# Science Meets Industry 2021
+
+![Task order](./tasks/order.svg)
+
+![Task order](./tasks/order.dot)

tasks/order.dot

+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_platform_cypress_psoc6 -> compile_smi21;
+    clone_repository_smi21 -> compile_smi21;
+    install_vscode_and_platformio -> install_platform_cypress_psoc6;
+    connect_psoc6_with_rc522 -> test_connection_psoc6_with_rc522;
+    write_first_test -> test_connection_psoc6_with_rc522;
+    upload_smi21 -> write_first_test;
+    compile_smi21 -> upload_smi21;
+    write_first_test -> test_wifi_connection;
+    test_wifi_connection -> test_http_request;
+    install_vscode_and_platformio -> optional_install_further_extensions;
+    test_connection_psoc6_with_rc522 -> read_nfc_uid;
+    read_nfc_uid -> read_nfc_hashtable;
+}

tasks/order.svg

+digraph G {
+	graph [bb="0,0,802.88,540",
+		fontname=helvetica
+	];
+	node [fontname=helvetica,
+		label="\N"
+	];
+	edge [fontname=helvetica];
+	install_vscode_and_platformio	[URL="install_vscode_and_platformio.md",
+		height=0.5,
+		pos="281.89,522",
+		width=3.5927];
+	install_platform_cypress_psoc6	[URL="install_platform_cypress_psoc6.md",
+		height=0.5,
+		pos="133.89,450",
+		width=3.7191];
+	install_vscode_and_platformio -> install_platform_cypress_psoc6	[pos="e,168.63,467.43 247.19,504.59 226.48,494.79 199.99,482.26 177.83,471.78"];
+	optional_install_further_extensions	[URL="optional_install_further_extensions.md",
+		height=0.5,
+		pos="430.89,450",
+		width=4.0441];
+	install_vscode_and_platformio -> optional_install_further_extensions	[pos="e,395.66,467.55 316.82,504.59 337.59,494.83 364.15,482.35 386.41,471.9"];
+	clone_repository_smi21	[URL="clone_repository_smi21.md",
+		height=0.5,
+		pos="698.89,450",
+		width=2.8886];
+	compile_smi21	[URL="compile_smi21.md",
+		height=0.5,
+		pos="415.89,378",
+		width=1.9498];
+	clone_repository_smi21 -> compile_smi21	[pos="e,464.71,391.08 641.96,434.92 593.34,422.89 523.67,405.66 474.55,393.51"];
+	upload_smi21	[URL="upload_smi21.md",
+		height=0.5,
+		pos="415.89,306",
+		width=1.8234];
+	compile_smi21 -> upload_smi21	[pos="e,415.89,324.1 415.89,359.7 415.89,351.98 415.89,342.71 415.89,334.11"];
+	connect_psoc6_with_rc522	[URL="connect_psoc6_with_rc522.md",
+		height=0.5,
+		pos="186.89,234",
+		width=3.2497];
+	test_connection_psoc6_with_rc522	[URL="test_connection_psoc6_with_rc522.md",
+		height=0.5,
+		pos="186.89,162",
+		width=4.0982];
+	connect_psoc6_with_rc522 -> test_connection_psoc6_with_rc522	[pos="e,186.89,180.1 186.89,215.7 186.89,207.98 186.89,198.71 186.89,190.11"];
+	install_platform_cypress_psoc6 -> compile_smi21	[pos="e,367.32,391.06 194.73,433.9 242.95,421.93 309.9,405.31 357.48,393.5"];
+	read_nfc_uid	[URL="read_nfc_uid.md",
+		height=0.5,
+		pos="186.89,90",
+		width=1.7151];
+	test_connection_psoc6_with_rc522 -> read_nfc_uid	[pos="e,186.89,108.1 186.89,143.7 186.89,135.98 186.89,126.71 186.89,118.11"];
+	test_http_request	[URL="test_http_request.md",
+		height=0.5,
+		pos="441.89,90",
+		width=2.1845];
+	test_wifi_connection	[URL="test_wifi_connection.md",
+		height=0.5,
+		pos="441.89,162",
+		width=2.4914];
+	test_wifi_connection -> test_http_request	[pos="e,441.89,108.1 441.89,143.7 441.89,135.98 441.89,126.71 441.89,118.11"];
+	write_first_test	[URL="write_first_test.md",
+		height=0.5,
+		pos="415.89,234",
+		width=1.8776];
+	upload_smi21 -> write_first_test	[pos="e,415.89,252.1 415.89,287.7 415.89,279.98 415.89,270.71 415.89,262.11"];
+	write_first_test -> test_connection_psoc6_with_rc522	[pos="e,238.83,178.88 373.35,220 338.29,209.28 288.1,193.94 248.62,181.87"];
+	write_first_test -> test_wifi_connection	[pos="e,435.47,180.28 422.18,216.05 425.11,208.18 428.66,198.62 431.94,189.79"];
+	read_nfc_hashtable	[URL="read_nfc_hashtable.md",
+		height=0.5,
+		pos="186.89,18",
+		width=2.4373];
+	read_nfc_uid -> read_nfc_hashtable	[pos="e,186.89,36.104 186.89,71.697 186.89,63.983 186.89,54.712 186.89,46.112"];
+}

tasks/read_nfc_hashtable.md

+# Read NFC Hashtable
+
+## Description
+
+Each NFC tag contains a table of snippet indices and hashes. We need to read this.
+
+### Tag data
+
+Each or our tags has a capability of 868 bytes data. The data is organized in blocks of 4 bytes:
+
+| Meaning   | Block | Data          |
+| :--       |   --: | :--           |
+| Metadata  |     0 | `xx xx xx xx` |
+| Metadata  |     1 | `xx xx xx xx` |
+| Metadata  |     2 | `xx xx xx xx` |
+| Metadata  |     3 | `xx xx xx xx` |
+| User data |     4 | `xx xx xx xx` |
+| User data |   ... | `xx xx xx xx` |
+| User data |   216 | `xx xx xx xx` |
+
+Each block can be read out using:
+
+```c
+uint8_t buffer[18];
+uint8_t buffer_size = sizeof(buffer);
+uint8_t status = nfc.MIFARE_Read(<BLOCK_NUMBER>, buffer, &buffer_size);
+```
+
+Note that always a buffer of 18 bytes need to be passed but only the first 4 bytes are valid.
+
+### Hashtable
+
+We stored SHA256 digests on the tag. Usually a SHA256 digest has 32 bytes. Due to the limited storage capacity we stored only 11 bytes of the digest.
+
+One snipped index plus hash uses 3 blocks, i.e. 12 bytes in total:
+
+| Block | Data                                                       |
+|   --: | :--                                                        |
+|     4 | `INDEX_0       HASH_0_BYTE_0 HASH_0_BYTE_1 HASH_0_BYTE_2`  |
+|     5 | `HASH_0_BYTE_3 HASH_0_BYTE_4 HASH_0_BYTE_5 HASH_0_BYTE_6`  |
+|     6 | `HASH_0_BYTE_7 HASH_0_BYTE_8 HASH_0_BYTE_9 HASH_0_BYTE_10` |
+|       |                                                            |
+|     7 | `INDEX_1       HASH_1_BYTE_0 HASH_1_BYTE_1 HASH_1_BYTE_2`  |
+|     8 | `HASH_1_BYTE_3 HASH_1_BYTE_4 HASH_1_BYTE_5 HASH_1_BYTE_6`  |
+|     9 | `HASH_1_BYTE_7 HASH_1_BYTE_8 HASH_1_BYTE_9 HASH_1_BYTE_10` |
+|       |                                                            |
+|       | ...                                                        |
+|       |                                                            |
+
+In total 64 of such index-hash-datasets are stored (i.e. 768 bytes) on each tag.
+
+## Prerequisites
+
+### Tasks done
+
+- [Read NFC UID](./read_nfc_uid.md)
+
+### State
+
+- NFC must be initialized, i.e. `nfc.PCD_Init()` called.
+- NFC UID must be read out, i.e. `nfc.PICC_ReadCardSerial()` successfully called.
+
+## Acceptance criteria
+
+- Index-Hash-Datasets can be read.
+
+## References
+
+- MFRC522 Header File: https://gitlab.elektrotechnik.hs-augsburg.de/hackenbs/mbed-mfrc522/-/blob/main/MFRC522.h
+
+## Hints
+
+- It might be helpful to have a function which reads one index-hash-dataset at once. E.g.:
+
+  ```c
+  int nfc_read_index_hash_set(uint8_t block, uint8_t &index, uint8_t hash[11]);
+  ```
+
+- You can verify your readout by using a NFC Smartphone App, e.g. https://play.google.com/store/apps/details?id=com.wakdev.wdnfc.

tasks/read_nfc_uid.md

+# Read NFC UID
+
+## Description
+
+Each NFC tag as a unique identifier (UID). This can be read out.
+
+## Prerequisites
+
+### Tasks done
+
+- [Test connection between PSoC6 and RC522 NFC reader](./test_connection_psoc6_with_rc522.md)
+
+### State
+
+- NFC must be initialized, i.e. `nfc.PCD_Init()` called.
+
+## Steps
+
+1. Wait for new tag:
+
+   ```c
+   bool result = false;
+   while (result != true)
+   {
+       result = nfc.PICC_IsNewCardPresent();
+   }
+   ```
+
+2. Read UID:
+
+   ```c
+   bool result = nfc.PICC_ReadCardSerial();
+   ```
+
+3. The UID can be accessed by `nfc.uid.uidByte` and printed e.g. with:
+
+   ```c
+   debugprintf("Tagid: ");
+   debugprintfhex(nfc.uid.uidByte, nfc.uid.size);
+   ```
+
+## Acceptance criteria
+
+- UID can be read out.
+
+## References
+
+- MFRC522 Header File: https://gitlab.elektrotechnik.hs-augsburg.de/hackenbs/mbed-mfrc522/-/blob/main/MFRC522.h