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03-serialuart/serialuart.ino

@@ -0,0 +1,113 @@
+#define BUFLEN      512
+#define SERIALSPEED 115200
+#define ERROR_SYNTAX  1
+#define ERROR_COMMAND 2
+
+typedef struct CmdParser {
+  char buffer[BUFLEN] = {0};
+  char atoibuf[32] = {0};
+  char *tok = NULL;
+  char *atoiptr = NULL;
+  int pin = 0;
+} CmdParser;
+
+void setup() {
+  Serial0.begin(SERIALSPEED, SERIAL_8N1, 21, 14);
+}
+
+int parse_digit_from_buffer(CmdParser *parser) 
+{
+  parser->atoiptr = parser->tok;
+  while ( *parser->atoiptr != ' ' && *parser->atoiptr != 0x00 ) {
+    if ( !isDigit((char)*parser->atoiptr) ) { 
+      Serial0.printf("Expected digit, found %s\n", parser->tok);
+      return ERROR_SYNTAX;
+    } else if (  parser->atoiptr == ((char *)&parser->buffer + 512 ) ) {
+      Serial0.printf("Reached end of string looking for next token : %s\n", parser->tok);
+      return ERROR_SYNTAX;
+    }
+    parser->atoiptr++;
+  }
+  strncpy((char *)&parser->atoibuf, parser->tok, (int)(parser->atoiptr - parser->tok));
+  parser->tok = parser->atoiptr;
+  return 0;
+}
+
+int command_writepin(CmdParser *parser)
+{
+  int rc = 0;
+  parser->tok = strtok(NULL, " ");
+  rc = parse_digit_from_buffer(parser);
+  if ( rc != 0 ) {
+    return rc;
+  }
+  parser->pin = atoi((char *)&parser->atoibuf);
+  parser->tok = strtok(NULL, " ");
+  if ( strncmp(parser->tok, "high", 4) == 0 ) {
+    digitalWrite(parser->pin, HIGH);
+    Serial0.printf("digitalWrite(%d, HIGH)", parser->pin);
+  } else if ( strncmp(parser->tok, "low", 3) == 0 ) {
+    digitalWrite(parser->pin, LOW);
+    Serial0.printf("digitalWrite(%d, LOW)", parser->pin);
+  } else {
+    Serial0.printf("Expected HIGH or LOW, found %s", parser->tok);
+    return ERROR_SYNTAX;
+  }
+  return 0;
+}
+
+int command_setpin(CmdParser *parser)
+{
+  int rc = 0;
+  parser->tok = strtok(NULL, " ");
+  rc = parse_digit_from_buffer(parser);
+  if ( rc != 0 ) {
+    return rc;
+  }
+  parser->pin = atoi((char *)&parser->atoibuf);
+  parser->tok = strtok(NULL, " ");
+  if ( strncmp(parser->tok, "input", 5) == 0 ) {
+    pinMode(parser->pin, INPUT);
+    Serial0.printf("pinMode(%d, INPUT)", parser->pin);
+  } else if ( strncmp(parser->tok, "output", 6) == 0 ) {
+    pinMode(parser->pin, OUTPUT);
+    Serial0.printf("pinMode(%d, OUTPUT)", parser->pin);
+  } else {
+    Serial0.printf("Expected input or output, found %s", parser->tok);
+    return ERROR_SYNTAX;
+  }
+  return 0;
+}
+
+int parse_command(CmdParser *parser)
+{
+  parser->tok = strtok((char *)&parser->buffer, " ");
+  if ( strcmp(parser->tok, "setpin") == 0 ) {
+    return command_setpin(parser);
+  } else if ( strcmp(parser->tok, "writepin") == 0 ) {
+    return command_writepin(parser);
+  }
+  return ERROR_COMMAND;
+}
+
+void loop() {
+  CmdParser parser;
+  memset((void *)&parser, 0x00, sizeof(CmdParser));
+  Serial0.println("");
+  Serial0.println("READY");
+  while ( Serial0.available() == 0 ) {
+    delay(10);
+  }
+  if ( Serial0.readBytesUntil('\0', (char *)&parser.buffer, BUFLEN) != 0 ) {
+    switch ( parse_command(&parser) ) {
+      case ERROR_SYNTAX:
+        Serial0.println("Syntax error");
+        break;
+      case ERROR_COMMAND:
+        Serial0.println("Unknown command");
+        break;
+      case 0:
+        return;
+    }
+  }
+}