altos/avr: Pull-up on the SPI slave select pin

This makes the board work even when disconnected from TeleMetrum.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/avr/ao_spi_slave.c b/src/avr/ao_spi_slave.c
index 76f574c6480f6ac1012f9a43295d1c75fa4a765b..3aa0b97f51496b0ff109a0efac48a68c89ce3f0f 100644 (file)
--- a/src/avr/ao_spi_slave.c
+++ b/src/avr/ao_spi_slave.c
@@ -87,7 +87,7 @@ ao_spi_slave_init(void)
                 (1 << 3) |             /* MISO, output */
                 (0 << 2) |             /* MOSI, no pull-up */
                 (0 << 1) |             /* SCK, no pull-up */
-                (0 << 0));             /* SS, no pull-up */
+                (1 << 0));             /* SS, pull-up */
 #endif
 #if SPI_SLAVE_PIN_2_5
        PCMSK0 |= (1 << PCINT2);        /* Enable PCINT2 pin change */
@@ -103,7 +103,7 @@ ao_spi_slave_init(void)
                 (0 << 5) |             /* SCK, no pull-up */
                 (1 << 4) |             /* MISO, output */
                 (0 << 3) |             /* MOSI, no pull-up */
-                (0 << 2));             /* SS, no pull-up */
+                (1 << 2));             /* SS, pull-up */
 #endif 
 
        SPCR = (0 << SPIE) |            /* Disable SPI interrupts */