diff options
Diffstat (limited to 'src/avr/ao_spi_usart.c')
| -rw-r--r-- | src/avr/ao_spi_usart.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/src/avr/ao_spi_usart.c b/src/avr/ao_spi_usart.c index 1996fcd9..5ea11da6 100644 --- a/src/avr/ao_spi_usart.c +++ b/src/avr/ao_spi_usart.c @@ -43,15 +43,17 @@ ao_spi_send(void __xdata *block, uint16_t len) __reentrant /* Receive bytes over SPI. * - * This sets up tow DMA engines, one reading the data and another - * writing constant values to the SPI transmitter as that is what - * clocks the data coming in. + * Poll, sending zeros and reading data back */ void ao_spi_recv(void __xdata *block, uint16_t len) __reentrant { uint8_t *d = block; + /* Clear any pending data */ + while (UCSR1A & (1 << RXC1)) + (void) UDR1; + while (len--) { while (!(UCSR1A & (1 << UDRE1))); UDR1 = 0; |