Toyomasa Watarai / BME280_SPI

BME280 Combined humidity and pressure sensor library with SPI interface

Dependents:   BME280_SPI_Hello

Fork of BME280 by Toyomasa Watarai

Files at this revision

API Documentation at this revision

Comitter:
MACRUM
Date:
Mon Mar 13 15:37:22 2017 +0000
Parent:
7:dfd6107f1f92
Commit message:
Change initialize values

Changed in this revision

BME280_SPI.cpp Show annotated file Show diff for this revision Revisions of this file
--- a/BME280_SPI.cpp	Mon Mar 13 07:23:21 2017 +0000
+++ b/BME280_SPI.cpp	Mon Mar 13 15:37:22 2017 +0000
@@ -55,12 +55,12 @@
 
     _cs = 0;
     _spi.write(0xf2 & BME280_SPI_MASK); // ctrl_hum
-    _spi.write(0x01); // Humidity oversampling x1
+    _spi.write(0x04); // Humidity oversampling x4
     _cs = 1;
 
     _cs = 0;
     _spi.write(0xf4 & BME280_SPI_MASK); // ctrl_meas
-    _spi.write(0x27); // Temparature oversampling x1, Pressure oversampling x1, Normal mode
+    _spi.write((4<<5)|(4<<2)|3); // Temparature oversampling x4, Pressure oversampling x4, Normal mode
     _cs = 1;
 
     _cs = 0;
@@ -68,6 +68,8 @@
     _spi.write(0xa0); // Standby 1000ms, Filter off, 4-wire SPI interface
     _cs = 1;
 
+    wait(1);
+    
     _cs = 0;
     _spi.write(0x88); // read dig_T regs
     for(int i = 0; i < 6; i++)
@@ -82,7 +84,7 @@
     DEBUG_PRINT("dig_T = %d, %d, %d\n", dig_T1, dig_T2, dig_T3);
 
     _cs = 0;
-    _spi.write(0x8e);
+    _spi.write(0x8e); // read dig_P regs
     for(int i = 0; i < 18; i++)
         cmd[i] = _spi.write(0);
     _cs = 1;
@@ -101,7 +103,7 @@
     DEBUG_PRINT("dig_P = %d, %d, %d, %d, %d, %d, %d, %d, %d\n", dig_P1, dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9);
 
     _cs = 0;
-    _spi.write(0xA1); // read dig_H regs
+    _spi.write(0xA1); // read dig_H1 reg
     cmd[0] = _spi.write(0);
     _cs = 1;
 
@@ -126,15 +128,15 @@
 {
     uint32_t temp_raw;
     float tempf;
-    char cmd[4];
+    char cmd[3];
 
     _cs = 0;
     _spi.write(0xfa);
     for(int i = 0; i < 3; i++)
-        cmd[1+i] = _spi.write(0);
+        cmd[i] = _spi.write(0);
     _cs = 1;
 
-    temp_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
+    temp_raw = (cmd[0] << 12) | (cmd[1] << 4) | (cmd[2] >> 4);
 
     int32_t temp;
 
@@ -153,15 +155,15 @@
 {
     uint32_t press_raw;
     float pressf;
-    char cmd[4];
+    char cmd[3];
 
     _cs = 0;
     _spi.write(0xf7); // press_msb
     for(int i = 0; i < 3; i++)
-        cmd[1+i] = _spi.write(0);
+        cmd[i] = _spi.write(0);
     _cs = 1;
 
-    press_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
+    press_raw = (cmd[0] << 12) | (cmd[1] << 4) | (cmd[2] >> 4);
 
     int32_t var1, var2;
     uint32_t press;
@@ -193,15 +195,15 @@
 {
     uint32_t hum_raw;
     float humf;
-    char cmd[4];
+    char cmd[2];
 
     _cs = 0;
     _spi.write(0xfd); // hum_msb
     for(int i = 0; i < 2; i++)
-        cmd[1+i] = _spi.write(0);
+        cmd[i] = _spi.write(0);
     _cs = 1;
 
-    hum_raw = (cmd[1] << 8) | cmd[2];
+    hum_raw = (cmd[0] << 8) | cmd[1];
 
     int32_t v_x1;