LowLatencyLogger mods

SdFat/examples/LowLatencyLogger/LowLatencyLogger.ino

 // Temporary log file.  Will be deleted if a reset or power failure occurs.
 #define TMP_FILE_NAME "tmp_log.bin"
 
-// Size of file base name.  Must not be larger than six.
+// Size of file base name.
 const uint8_t BASE_NAME_SIZE = sizeof(FILE_BASE_NAME) - 1;
 const uint8_t FILE_NAME_DIM  = BASE_NAME_SIZE + 7;
 char binName[FILE_NAME_DIM] = FILE_BASE_NAME "00.bin";
   if (sizeof(block_t) != 512) {
     error("Invalid block size");
   }
+  // Allow userSetup access to SPI bus.
+  pinMode(SD_CS_PIN, OUTPUT);
+  digitalWrite(SD_CS_PIN, HIGH);
+  
+  // Setup sensors.
+  userSetup();
+  
   // Initialize at the highest speed supported by the board that is
   // not over 50 MHz. Try a lower speed if SPI errors occur.
   if (!sd.begin(SD_CS_PIN, SD_SCK_MHZ(50))) {
     sd.initErrorPrint(&Serial);
     fatalBlink();
   }
-  userSetup();
 }
 //------------------------------------------------------------------------------
 void loop(void) {

SdFat/examples/LowLatencyLogger/UserFunctions.cpp

 // User data functions.  Modify these functions for your data items.
 
 // Start time for data
-uint32_t startTime;
+static uint32_t startMicros;
 
 // Acquire a data record.
 void acquireData(data_t* data) {
 
 // Print a data record.
 void printData(Print* pr, data_t* data) {
-  if (startTime == 0) {
-    startTime = data->time;
+  if (startMicros == 0) {
+    startMicros = data->time;
   }
-  pr->print(data->time - startTime);
+  pr->print(data->time - startMicros);
   for (int i = 0; i < ADC_DIM; i++) {
     pr->write(',');
     pr->print(data->adc[i]);
 
 // Print data header.
 void printHeader(Print* pr) {
-  startTime = 0;
+  startMicros = 0;
   pr->print(F("micros"));
   for (int i = 0; i < ADC_DIM; i++) {
     pr->print(F(",adc"));

SdFat/examples/LowLatencyLogger/UserTypes.h

 #define FILE_BASE_NAME "adc4pin"
 const uint8_t ADC_DIM = 4;
 struct data_t {
-  unsigned long time;
-  unsigned short adc[ADC_DIM];
+  uint32_t time;
+  uint16_t adc[ADC_DIM];
 };
 void acquireData(data_t* data);
 void printData(Print* pr, data_t* data);

SdFat/examples/LowLatencyLoggerADXL345/LowLatencyLogger.ino

 // Temporary log file.  Will be deleted if a reset or power failure occurs.
 #define TMP_FILE_NAME "tmp_log.bin"
 
-// Size of file base name.  Must not be larger than six.
+// Size of file base name.
 const uint8_t BASE_NAME_SIZE = sizeof(FILE_BASE_NAME) - 1;
 const uint8_t FILE_NAME_DIM  = BASE_NAME_SIZE + 7;
 char binName[FILE_NAME_DIM] = FILE_BASE_NAME "00.bin";
   if (sizeof(block_t) != 512) {
     error("Invalid block size");
   }
+  // Allow userSetup access to SPI bus.
+  pinMode(SD_CS_PIN, OUTPUT);
+  digitalWrite(SD_CS_PIN, HIGH);
+  
+  // Setup sensors.
+  userSetup();
+  
   // Initialize at the highest speed supported by the board that is
   // not over 50 MHz. Try a lower speed if SPI errors occur.
   if (!sd.begin(SD_CS_PIN, SD_SCK_MHZ(50))) {
     sd.initErrorPrint(&Serial);
     fatalBlink();
   }
-  userSetup();
 }
 //------------------------------------------------------------------------------
 void loop(void) {

SdFat/examples/LowLatencyLoggerADXL345/UserFunctions.cpp

 const uint8_t DATAZ1 = 0x37; //Z-Axis Data 1
 
 void writeADXL345Register(const uint8_t registerAddress, const uint8_t value) {
+  // Max SPI clock frequency is 5 MHz with CPOL = 1 and CPHA = 1.
+  SPI.beginTransaction(SPISettings(5000000, MSBFIRST, SPI_MODE3));  
   digitalWrite(ADXL345_CS, LOW);
   SPI.transfer(registerAddress);
   SPI.transfer(value);
   digitalWrite(ADXL345_CS, HIGH);
+  SPI.endTransaction();  
 }
 
 void userSetup() {

SdFat/examples/LowLatencyLoggerADXL345/UserTypes.h

 // User data types.  Modify for your data items.
 const uint8_t ACCEL_DIM = 3;
 struct data_t {
-  unsigned long time;
+  uint32_t time;
   int16_t accel[ACCEL_DIM];
 };
 void acquireData(data_t* data);

SdFat/examples/LowLatencyLoggerMPU6050/LowLatencyLogger.ino

 #ifdef ERROR_LED_PIN
 #undef ERROR_LED_PIN
 #endif  // ERROR_LED_PIN
-const int8_t ERROR_LED_PIN = 3;
+const int8_t ERROR_LED_PIN = -1;
 //------------------------------------------------------------------------------
 // File definitions.
 //
 // Temporary log file.  Will be deleted if a reset or power failure occurs.
 #define TMP_FILE_NAME "tmp_log.bin"
 
-// Size of file base name.  Must not be larger than six.
+// Size of file base name.
 const uint8_t BASE_NAME_SIZE = sizeof(FILE_BASE_NAME) - 1;
 const uint8_t FILE_NAME_DIM  = BASE_NAME_SIZE + 7;
 char binName[FILE_NAME_DIM] = FILE_BASE_NAME "00.bin";
   if (sizeof(block_t) != 512) {
     error("Invalid block size");
   }
+  // Allow userSetup access to SPI bus.
+  pinMode(SD_CS_PIN, OUTPUT);
+  digitalWrite(SD_CS_PIN, HIGH);
+  
+  // Setup sensors.
+  userSetup();
+  
   // Initialize at the highest speed supported by the board that is
   // not over 50 MHz. Try a lower speed if SPI errors occur.
   if (!sd.begin(SD_CS_PIN, SD_SCK_MHZ(50))) {
     sd.initErrorPrint(&Serial);
     fatalBlink();
   }
-  userSetup();
 }
 //------------------------------------------------------------------------------
 void loop(void) {