Diff: adns9500.cpp

Revision:

9:8b1e889e94fe

Parent:

8:97e5df54b8bb

Child:

10:bbf9ff378632

--- a/adns9500.cpp	Tue Jul 10 13:29:45 2012 +0000
+++ b/adns9500.cpp	Wed Jul 11 13:39:21 2012 +0000
@@ -81,7 +81,7 @@
         ncs_.write(0);
         WAIT_TNCSSCLK();
         
-        // send 0x3a to POWER_UP_RESET and wait for at least 50ms
+        // send 0x5a to POWER_UP_RESET and wait for at least 50ms
         spiSend(POWER_UP_RESET, 0x5a);
         LONG_WAIT_MS(50);
         
@@ -89,18 +89,16 @@
         spiSend(OBSERVATION, 0x00);
         LONG_WAIT_US(DEFAULT_MAX_FRAME_PERIOD);
 
-        WAIT_TSCLKNCS();
-        ncs_.write(1);
-
         // check observation register bits [5:0]
         int observation = spiReceive(OBSERVATION);
-        if (! ADNS9500_IF_OBSERVATION_TEST(observation))
+        if (! ADNS9500_IF_OBSERVATION_TEST(observation)) {
+            WAIT_TSCLKNCS();
+            ncs_.write(1);
+
             error("ADNS9500::reset : observation register test failed: 0x%x\n", observation);
+        }
 
         // read motion data
-        ncs_.write(0);
-        WAIT_TNCSSCLK();
-
         WAIT_TSRR();
         spiReceive(MOTION);
         WAIT_TSRR();
@@ -149,7 +147,7 @@
         ncs_.write(0);
         WAIT_TNCSSCLK();
         
-        // send 0x3a to POWER_UP_RESET
+        // send 0x5a to POWER_UP_RESET
         spiSend(POWER_UP_RESET, 0x5a);
         
         WAIT_TSCLKNCS();