[avr + fluksod] enable crc checking in both spi directions

mote/v2/avr/ctrl.c

@@ -205,23 +205,39 @@ void ctrlRxToTxLoop(void)
 	}
 }
 
-uint8_t ctrlCalcCrc8(cBuffer* buffer)
+uint8_t ctrlCalcCrc8(cBuffer* buffer, uint8_t chop)
 {
 	uint8_t i, crc = 0;
 
-	for (i = 0; i < buffer->datalength; i++) {
+	for (i = 0; i < buffer->datalength - chop; i++) {
 		crc = _crc_ibutton_update(crc, bufferGetAtIndex(buffer, i));
 	}
 	return crc;
 }
 
+uint8_t ctrlExtractCrc8fromMessage(cBuffer* buffer)
+{
+	uint8_t crc, high_hex, low_hex;
+
+	high_hex = bufferGetAtIndex(buffer, buffer->datalength - 2);
+	low_hex  = bufferGetAtIndex(buffer, buffer->datalength - 1);
+
+	htob(high_hex, low_hex, &crc);
+	return crc;
+}
+
 void ctrlDecode(void)
 {
 	uint8_t cmd[2], crc;
 
 	ctrlFlushTxBuffer();
 
-	if (ctrlGetFromRxBuffer(cmd) && ctrlGetFromRxBuffer(cmd+1)) {
+	crc = ctrlExtractCrc8fromMessage(&ctrlRxBuffer);
+	if (ctrlCalcCrc8(&ctrlRxBuffer, 2) != crc) {
+		ctrlAddToTxBuffer('z');
+		ctrlAddToTxBuffer('z');
+	}
+	else if (ctrlGetFromRxBuffer(cmd) && ctrlGetFromRxBuffer(cmd+1)) {
 		ctrlAddToTxBuffer(cmd[0]);
 		ctrlAddToTxBuffer(cmd[1]);
 
@@ -238,12 +254,16 @@ void ctrlDecode(void)
 			if (cmd[1] == 't') ctrlCmdCommit();
 			break;
 		}
-
-		crc = ctrlCalcCrc8(&ctrlTxBuffer);
-		ctrlWriteCharToTxBuffer(crc);
-
-		ctrlAddToTxBuffer('.');
 	}
+	else {
+		ctrlAddToTxBuffer('z');
+		ctrlAddToTxBuffer('y');
+	}
+
+	crc = ctrlCalcCrc8(&ctrlTxBuffer, 0);
+	ctrlWriteCharToTxBuffer(crc);
+
+	ctrlAddToTxBuffer('.');
 
 	ctrlFlushRxBuffer();
 }

mote/v2/avr/ctrl.h

@@ -108,9 +108,19 @@ void ctrlRxToTxLoop(void);
  * Calculate the CRC-8 checksum over the bytes in the buffer.
  *
  * @param buffer  pointer to the buffer containing the data
+ * @param chop    chop number of bytes from end of buffer for crc calc
  * @return        CRC-8 checksum
  */
-uint8_t ctrlCalcCrc8(cBuffer* buffer);
+uint8_t ctrlCalcCrc8(cBuffer* buffer, uint8_t chop);
+
+
+/**
+ * Extract the CRC-8 checksum out of the message in the buffer.
+ *
+ * @param buffer  pointer to the buffer containing the message
+ * @return        CRC-8 checksum
+ */
+uint8_t ctrlExtractCrc8fromMessage(cBuffer* buffer);
 
 /**
  * Decode the message in the ctrl Rx buffer and dispatch to either ctrlCmdGet,

mote/v2/avr/main.c

@@ -122,7 +122,6 @@ ISR(SPI_STC_vect)
 			break;
 		case SPI_END_OF_MESSAGE:
 			if (!(spi_status & SPI_TO_FROM_UART)) {
-				ctrlAddToRxBuffer(spi_rx);
 				spi_status |= SPI_NEW_CTRL_MSG;
 			}
 			break;

mote/v2/openwrt/package/flukso/luasrc/flukso/spi.lua

@@ -100,7 +100,7 @@ function encode(msg)
 
 	end
 
---> TODO msg.encoded = msg.encoded .. dow_crc(msg.encoded)
+	msg.encoded = msg.encoded .. nixio.bin.numtohex(nixio.bin.dow_crc(msg.encoded), 1)
 end
 
 function tx(msg, cdev)