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-rw-r--r--Projects/XPLAINBridge/Lib/SoftUART.c20
1 files changed, 13 insertions, 7 deletions
diff --git a/Projects/XPLAINBridge/Lib/SoftUART.c b/Projects/XPLAINBridge/Lib/SoftUART.c
index 458a505cd..90c23b71d 100644
--- a/Projects/XPLAINBridge/Lib/SoftUART.c
+++ b/Projects/XPLAINBridge/Lib/SoftUART.c
@@ -76,15 +76,21 @@ void SoftUART_Init(void)
/** ISR to detect the start of a bit being sent to the software UART. */
ISR(INT0_vect, ISR_BLOCK)
{
- /* Reset and start the reception timer */
- TCNT1 = 0;
- TCCR1B = ((1 << CS10) | (1 << WGM12));
-
/* Reset the number of reception bits remaining counter */
RX_BitsRemaining = 8;
+
+ /* Reset the bit reception timer */
+ TCNT1 = 0;
+
+ /* Check to see that the pin is still low (prevents glitches from starting a frame reception) */
+ if (!(SRXPIN & (1 << SRX)))
+ {
+ /* Disable start bit detection ISR while the next byte is received */
+ EIMSK = 0;
- /* Disable start bit detection ISR while the next byte is received */
- EIMSK = 0;
+ /* Start the reception timer */
+ TCCR1B = ((1 << CS10) | (1 << WGM12));
+ }
}
/** ISR to manage the reception of bits to the software UART. */
@@ -133,7 +139,7 @@ ISR(TIMER3_COMPA_vect, ISR_NOBLOCK)
TX_Data >>= 1;
TX_BitsRemaining--;
}
- else if (USBtoUART_Buffer.Count)
+ else if (USBtoUART_Buffer.Count && !(RX_BitsRemaining))
{
/* Start bit - TX line low */
STXPORT &= ~(1 << STX);