diff options
Diffstat (limited to 'Projects/XPLAINBridge/Lib/SoftUART.c')
| -rw-r--r-- | Projects/XPLAINBridge/Lib/SoftUART.c | 61 |
1 files changed, 27 insertions, 34 deletions
diff --git a/Projects/XPLAINBridge/Lib/SoftUART.c b/Projects/XPLAINBridge/Lib/SoftUART.c index 5e589f3d7..18d5c01bd 100644 --- a/Projects/XPLAINBridge/Lib/SoftUART.c +++ b/Projects/XPLAINBridge/Lib/SoftUART.c @@ -30,27 +30,16 @@ this software. */ -#include "SoftUART.h" - -volatile bool srx_done; -volatile uint8_t stx_count; -static uint8_t srx_data, srx_mask, srx_tmp, stx_data; - -void SoftUART_TxByte(uint8_t Byte) -{ - while (stx_count); +/** \file + * + * Software UART for both data transmission and reception. This + * code continuously monitors the ring buffers set up by the main + * project source file and reads/writes data as it becomes available. + */ - stx_data = ~Byte; - stx_count = 10; -} - -uint8_t SoftUART_RxByte(void) -{ - while (!(srx_done)); - srx_done = false; +#include "SoftUART.h" - return srx_data; -} +static uint8_t TX_BitsRemaining, TX_Data, RX_BitMask, RX_Data; void SoftUART_Init(void) { @@ -61,8 +50,7 @@ void SoftUART_Init(void) EICRA = (1 << ISC01); // -ve edge EIMSK = (1 << INT0); // enable INT0 interrupt - stx_count = 0; // nothing to send - srx_done = false; // nothing received + TX_BitsRemaining = 0; // nothing to send STXPORT |= (1 << STX); // TX output STXDDR |= (1 << STX); // TX output SRXPORT |= (1 << SRX); // pullup on INT0 @@ -73,8 +61,8 @@ ISR(INT0_vect) { OCR2A = TCNT2 + (BIT_TIME / 8 * 3 / 2); // scan 1.5 bits after start - srx_tmp = 0; // clear bit storage - srx_mask = 1; // bit mask + RX_Data = 0; // clear bit storage + RX_BitMask = (1 << 0); // bit mask TIFR2 = (1 << OCF2A); // clear pending interrupt @@ -88,19 +76,19 @@ ISR(INT0_vect) /* ISR to manage the reception of bits to the transmitter. */ ISR(TIMER2_COMPA_vect) { - if (srx_mask) + if (RX_BitMask) { if (SRXPIN & (1 << SRX)) - srx_tmp |= srx_mask; + RX_Data |= RX_BitMask; - srx_mask <<= 1; + RX_BitMask <<= 1; OCR2A += BIT_TIME / 8; // next bit slice } else { - srx_done = true; // mark rx data valid - srx_data = srx_tmp; // store rx data + RingBuffer_Insert(&UARTtoUSB_Buffer, RX_Data); + TIMSK2 = (1 << OCIE2B); // enable tx and wait for start EIMSK |= (1 << INT0); // enable START irq EIFR = (1 << INTF0); // clear any pending @@ -112,20 +100,25 @@ ISR(TIMER2_COMPB_vect) { OCR2B += BIT_TIME / 8; // next bit slice - if (stx_count) + if (TX_BitsRemaining) { - if (--stx_count != 9) // no start bit + if (--TX_BitsRemaining != 9) // no start bit { - if (!(stx_data & 1)) // test inverted data - TCCR2A = (1 << COM2B1) | (1 << COM2B0); - else + if (TX_Data & (1 << 0)) // test inverted data TCCR2A = (1 << COM2B1); + else + TCCR2A = (1 << COM2B1) | (1 << COM2B0); - stx_data >>= 1; // shift zero in from left + TX_Data >>= 1; // shift zero in from left } else { TCCR2A = (1 << COM2B1); // START bit } } + else if (USBtoUART_Buffer.Count) + { + TX_Data = ~RingBuffer_Remove(&USBtoUART_Buffer); + TX_BitsRemaining = 10; + } } |