Started following some tutorial on att85 usi. Downloaded example code from make avr book.

2022-09-20 01:08:01 -04:00
parent d0cbc0000e
commit 361a828c46
295 changed files with 68746 additions and 0 deletions
--- a/Examples/Chapter19_EEPROM/vigenereCipher/vigenereCipher.c
+++ b/Examples/Chapter19_EEPROM/vigenereCipher/vigenereCipher.c
@@ -0,0 +1,146 @@
+/*
+Vigenere Cipher encoder / decoder demo
+And an excuse to play around with EEPROM memory
+ */
+
+#include "vigenereCipher.h"
+
+// -------- Functions --------- //
+
+void printFromEEPROM(char *eepromString) {
+  uint8_t letter;
+  do {
+    letter = eeprom_read_byte((uint8_t *) eepromString);
+    transmitByte(letter);
+    eepromString++;
+  } while (letter);
+}
+
+void enterText(char text[]) {
+  uint8_t i = 0;
+  char letter;
+  do {
+    letter = receiveByte();
+    transmitByte(letter);                                      /* echo */
+    text[i] = letter;
+    i++;
+  } while (!(letter == '\r') && (i < (MAX_TEXT_LENGTH - 1)));
+  text[i - 1] = 0;
+}
+
+void displayCodes(void) {
+  uint8_t i;
+  for (i = 0; i < 4; i++) {
+    transmitByte(' ');
+    transmitByte('0' + i);
+    printString(": ");
+    printFromEEPROM(codePointers[i]);
+    printString("\r\n");
+  }
+}
+
+void changeCode(char codeBuffer[]) {
+  char input;
+  char *codeAddress;
+  printString(" -- Choose code phrase to replace:\r\n");
+  do {
+    displayCodes();
+    input = receiveByte();
+  } while ((input < '0') || (input > '3'));
+  codeAddress = codePointers[input - '0'];
+  printString(" -- Enter new code: ");
+  enterText(codeBuffer);
+  eeprom_update_block(codeBuffer, codeAddress, CODE_LEN);
+}
+
+void selectCode(char code[]) {
+  char input;
+  char *codeAddress;
+  printFromEEPROM(promptSelectCode);
+  do {
+    displayCodes();
+    input = receiveByte();
+  } while ((input < '0') || (input > '3'));
+  codeAddress = codePointers[input - '0'];
+  eeprom_read_block(code, codeAddress, CODE_LEN);
+}
+
+void encodeVigenere(char text[], char code[]) {
+  uint8_t codePosition = 0;
+  uint8_t textPosition = 0;
+  do {
+    if (code[codePosition] == 0) {  /* loop when at end of code phrase */
+      codePosition = 0;
+    }
+    text[textPosition] += code[codePosition] - 32;
+    if (text[textPosition] > 126) {
+      text[textPosition] -= 95;
+    }                              /* keeps within printing characters */
+    codePosition++;                         /* and move on to the next */
+    textPosition++;
+  } while (text[textPosition]);     /* until zero at the end of string */
+}
+
+void decodeVigenere(char text[], char code[]) {
+  uint8_t codePosition = 0;
+  uint8_t textPosition = 0;
+  do {
+    if (code[codePosition] == 0) {
+      codePosition = 0;
+    }
+    if (code[codePosition] > text[textPosition]) {
+      text[textPosition] += 95;
+    }                              /* keeps within printing characters */
+    text[textPosition] -= code[codePosition] - 32;
+    codePosition++;
+    textPosition++;
+  } while (text[textPosition]);
+}
+
+int main(void) {
+  // -------- Inits --------- //
+
+  char textBuffer[MAX_TEXT_LENGTH];
+  char codeString[CODE_LEN];
+  char input;
+  initUSART();
+
+  // ------ Event loop ------ //
+  while (1) {
+
+    // Menu
+    printFromEEPROM(welcomeString);
+    printFromEEPROM(promptText);
+    printString(textBuffer);
+    printString("\r\n");
+    printFromEEPROM(promptCode);
+    printString(codeString);
+    printString("\r\n\r\n ---------------------\r\n");
+    printFromEEPROM(menuEnterText);
+    printFromEEPROM(menuCodeText);
+    printFromEEPROM(menuChangeCode);
+    printFromEEPROM(menuEncode);
+    printFromEEPROM(menuDecode);
+    input = receiveByte();
+
+    switch (input) {
+    case 'e':                  // encode
+      encodeVigenere(textBuffer, codeString);
+      break;
+    case 'd':                  // decode
+      decodeVigenere(textBuffer, codeString);
+      break;
+    case 'n':                  // new text
+      printFromEEPROM(promptTypeText);
+      enterText(textBuffer);
+      break;
+    case 'c':                  // choose code
+      selectCode(codeString);
+      break;
+    case 'x':                  // change code
+      changeCode(codeString);
+      break;
+    }
+  }                                                  /* End event loop */
+  return 0;                            /* This line is never reached */
+}