Make XPLAINBridge serial bridge much more reliable for the reception of characters...

[pub/USBasp.git] / Projects / XPLAINBridge / Lib / SoftUART.c

diff --git a/Projects/XPLAINBridge/Lib/SoftUART.c b/Projects/XPLAINBridge/Lib/SoftUART.c
index 81f0237..02223af 100644 (file)
--- a/Projects/XPLAINBridge/Lib/SoftUART.c
+++ b/Projects/XPLAINBridge/Lib/SoftUART.c
@@ -54,12 +54,12 @@ static uint8_t RX_Data;
 /** Initializes the software UART, ready for data transmission and reception into the global ring buffers. */
 void SoftUART_Init(void)
 {
-       /* Set TX pin to output high, enable RX pullup */
+       /* Set TX pin to output high, enable RX pull-up */
        STXPORT |= (1 << STX);
        STXDDR  |= (1 << STX);
        SRXPORT |= (1 << SRX);
 
-       /* Enable INT0 for the detection of incomming start bits that signal the start of a byte */
+       /* Enable INT0 for the detection of incoming start bits that signal the start of a byte */
        EICRA  = (1 << ISC01);
        EIMSK  = (1 << INT0);
 
@@ -79,18 +79,12 @@ ISR(INT0_vect, ISR_BLOCK)
        RX_Data    = 0;
        RX_BitMask = (1 << 0);
 
-       /* Check that the start bit is still low to prevent noise from triggering a reception */
-       if (!(SRXPIN & (1 << SRX)))
-       {
-               /* Clear reception channel ISR flag in case it is pending */
-               TIFR1 = (1 << OCF1A);
-
-               /* Still low, enable bit receive ISR */
-               TIMSK1 =  (1 << OCIE1A);                
+       /* Clear reception channel ISR flag and enable the bit reception ISR */
+       TIFR1  = (1 << OCF1A);
+       TIMSK1 = (1 << OCIE1A);         
 
-               /* Clear the start bit detection ISR flag */
-               EIMSK &= ~(1 << INT0);
-       }
+       /* Disable start bit detection ISR while the next byte is received */
+       EIMSK &= ~(1 << INT0);
 }
 
 /** ISR to manage the reception of bits to the software UART. */