Version 1.0.3 prep

Fix reassignment of variable in pressure calculation algo

README.md

@@ -6,6 +6,20 @@ The state-of-the-art BME680 breakout lets you measure temperature, pressure, hum
 
 ## Installing
 
+### Full install (recommended):
+
+We've created an easy installation script that will install all pre-requisites and get your BME680
+up and running with minimal efforts. To run it, fire up Terminal which you'll find in Menu -> Accessories -> Terminal
+on your Raspberry Pi desktop, as illustrated below:
+
+![Finding the terminal](http://get.pimoroni.com/resources/github-repo-terminal.png)
+
+In the new terminal window type the command exactly as it appears below (check for typos) and follow the on-screen instructions:
+
+```bash
+curl https://get.pimoroni.com/bme680 | bash
+```
+
 ### Manual install:
 
 #### Library install for Python 3:

library/CHANGELOG.txt

@@ -1,3 +1,8 @@
+1.0.3
+-----
+
+* Merged temperature compensation fix from Bosch's BME680_driver 3.5.3
+
 1.0.2
 -----
 

library/bme680/__init__.py

@@ -2,7 +2,7 @@ from .constants import *
 import math
 import time
 
-__version__ = '1.0.2'
+__version__ = '1.0.3'
 
 class BME680(BME680Data):
     """BOSCH BME680
@@ -287,63 +287,72 @@ class BME680(BME680Data):
             return self._i2c.read_i2c_block_data(self.i2c_addr, register, length)
         
     def _calc_temperature(self, temperature_adc):
-        var1 = (temperature_adc / 8) - (self.calibration_data.par_t1 * 2)
+        var1 = (temperature_adc >> 3) - (self.calibration_data.par_t1 << 1)
-        var2 = (var1 * self.calibration_data.par_t2) / 2048
+        var2 = (var1 * self.calibration_data.par_t2) >> 11
-        var3 = ((var1 / 2) * (var1 / 2)) / 4096
+        var3 = ((var1 >> 1) * (var1 >> 1)) >> 12
-        var3 = ((var3) * (self.calibration_data.par_t3 * 16)) / 16384
+        var3 = ((var3) * (self.calibration_data.par_t3 << 4)) >> 14
 
         # Save teperature data for pressure calculations
         self.calibration_data.t_fine = (var2 + var3)
-        calc_temp = (((self.calibration_data.t_fine * 5) + 128) / 256)
+        calc_temp = (((self.calibration_data.t_fine * 5) + 128) >> 8)
 
         return calc_temp
 
     def _calc_pressure(self, pressure_adc):
-        var1 = (self.calibration_data.t_fine / 2) - 64000
+        var1 = ((self.calibration_data.t_fine) >> 1) - 64000
-        var2 = ((var1 / 4) * (var1 / 4)) / 2048
+        var2 = ((((var1 >> 2) * (var1 >> 2)) >> 11) *
-        var2 = (var2 * self.calibration_data.par_p6) / 4
+            self.calibration_data.par_p6) >> 2
-        var2 = var2 + ((var1 * self.calibration_data.par_p5) * 2)
+        var2 = var2 + ((var1 * self.calibration_data.par_p5) << 1)
-        var2 = (var2 / 4) + (self.calibration_data.par_p4 * 65536)
+        var2 = (var2 >> 2) + (self.calibration_data.par_p4 << 16)
+        var1 = (((((var1 >> 2) * (var1 >> 2)) >> 13 ) *
+                ((self.calibration_data.par_p3 << 5)) >> 3) +
+                ((self.calibration_data.par_p2 * var1) >> 1))
+        var1 = var1 >> 18
 
-        var1 = ((var1 / 4) * (var1 / 4)) / 8192
+        var1 = ((32768 + var1) * self.calibration_data.par_p1) >> 15
-        var1 = ((var1 * (self.calibration_data.par_p3 * 32)) / 8) + ((self.calibration_data.par_p2 * var1) / 2)
+        calc_pressure = 1048576 - pressure_adc
-        var1 = var1 / 262144
+        calc_pressure = ((calc_pressure - (var2 >> 12)) * (3125))
-        var1 = ((32768 + var1) * self.calibration_data.par_p1) / 32768
-        calc_pres = 1048576 - pressure_adc
-        calc_pres = (calc_pres - (var2 / 4096)) * 3125
-        calc_pres = (calc_pres / var1) * 2
-        var1 = (self.calibration_data.par_p9 * (((calc_pres / 8) * (calc_pres / 8)) / 8192)) / 4096
-        var2 = ((calc_pres / 4) * self.calibration_data.par_p8) / 8192
-        var3 = ((calc_pres / 256)
-                * (calc_pres / 256)
-                * (calc_pres / 256)
-                * self.calibration_data.par_p10) / 131072
-        calc_pres = calc_pres + ((var1 + var2 + var3 + (self.calibration_data.par_p7 * 128)) / 16)
 
-        return calc_pres
+        if calc_pressure >= (1 << 31):
+            calc_pressure = ((calc_pressure // var1) << 1)
+        else:
+            calc_pressure = ((calc_pressure << 1) // var1)
+
+        var1 = (self.calibration_data.par_p9 * (((calc_pressure >> 3) *
+            (calc_pressure >> 3)) >> 13)) >> 12
+        var2 = ((calc_pressure >> 2) *
+            self.calibration_data.par_p8) >> 13
+        var3 = ((calc_pressure >> 8) * (calc_pressure >> 8) *
+            (calc_pressure >> 8) *
+            self.calibration_data.par_p10) >> 17
+
+        calc_pressure = (calc_pressure) + ((var1 + var2 + var3 +
+            (self.calibration_data.par_p7 << 7)) >> 4)
+
+        return calc_pressure
 
     def _calc_humidity(self, humidity_adc):
-        temp_scaled = ((self.calibration_data.t_fine * 5) + 128) / 256
+        temp_scaled = ((self.calibration_data.t_fine * 5) + 128) >> 8
         var1 = (humidity_adc - ((self.calibration_data.par_h1 * 16))) \
-                - (((temp_scaled * self.calibration_data.par_h3) / (100)) / 2)
+                - (((temp_scaled * self.calibration_data.par_h3) // (100)) >> 1)
         var2 = (self.calibration_data.par_h2
-                * (((temp_scaled * self.calibration_data.par_h4) / (100))
+                * (((temp_scaled * self.calibration_data.par_h4) // (100))
-                + (((temp_scaled * ((temp_scaled * self.calibration_data.par_h5) / (100))) / 64)
+                + (((temp_scaled * ((temp_scaled * self.calibration_data.par_h5) // (100))) >> 6)
-                / (100)) + (1 * 16384))) / 1024
+                // (100)) + (1 * 16384))) >> 10
         var3 = var1 * var2
-        var4 = self.calibration_data.par_h6 * 128
+        var4 = self.calibration_data.par_h6 << 7
-        var4 = ((var4) + ((temp_scaled * self.calibration_data.par_h7) / (100))) / 16
+        var4 = ((var4) + ((temp_scaled * self.calibration_data.par_h7) // (100))) >> 4
-        var5 = ((var3 / 16384) * (var3 / 16384)) / 1024
+        var5 = ((var3 >> 14) * (var3 >> 14)) >> 10
-        var6 = (var4 * var5) / 2
+        var6 = (var4 * var5) >> 1
-        calc_hum = (((var3 + var6) / 1024) * (1000)) / 4096
+        calc_hum = (((var3 + var6) >> 10) * (1000)) >> 12
 
         return min(max(calc_hum,0),100000)
 
     def _calc_gas_resistance(self, gas_res_adc, gas_range):
-        var1 = ((1340 + (5 * self.calibration_data.range_sw_err)) * (lookupTable1[gas_range])) / 65536
+        var1 = ((1340 + (5 * self.calibration_data.range_sw_err)) * (lookupTable1[gas_range])) >> 16
-        var2 = (((gas_res_adc * 32768) - (16777216)) + var1)
+        var2 = (((gas_res_adc << 15) - (16777216)) + var1)
-        var3 = ((lookupTable2[gas_range] * var1) / 512)
+        var3 = ((lookupTable2[gas_range] * var1) >> 9)
-        calc_gas_res = ((var3 + (var2 / 2)) / var2)
+        calc_gas_res = ((var3 + (var2 >> 1)) / var2)
 
         return calc_gas_res
 

library/bme680/constants.py

@@ -323,9 +323,9 @@ class CalibrationData:
         self.par_gh3 = twos_comp(calibration[GH3_REG], bits=8)
 
     def set_other(self, heat_range, heat_value, sw_error):
-        self.res_heat_range = (heat_range & RHRANGE_MSK) / 16
+        self.res_heat_range = (heat_range & RHRANGE_MSK) // 16
         self.res_heat_val = heat_value
-        self.range_sw_err = (sw_error * RSERROR_MSK) / 16
+        self.range_sw_err = (sw_error * RSERROR_MSK) // 16
 
 # BME680 sensor settings structure which comprises of ODR,
 # over-sampling and filter settings.

library/setup.py

@@ -39,7 +39,7 @@ classifiers = ['Development Status :: 5 - Production/Stable',
 
 setup(
     name            = 'bme680',
-    version         = '1.0.2',
+    version         = '1.0.3',
     author          = 'Philip Howard',
     author_email    = 'phil@pimoroni.com',
     description     = """Python library for driving the Pimoroni BME680 Breakout""",

packaging/CHANGELOG

@@ -1,3 +1,9 @@
+bme680 (1.0.3) stable; urgency=low
+
+  * Merged temperature compensation fix from Bosch's BME680_driver 3.5.3
+
+ -- Phil Howard <phil@pimoroni.com>  Wed, 22 Nov 2017 00:00:00 +0000
+
 bme680 (1.0.2) stable; urgency=low
 
   * Fixed set_gas_heater_temperature to avoid i2c TypeError

packaging/bme680_1.0.2_armhf.raspberrypi.upload

@@ -0,0 +1,5 @@
+Successfully uploaded bme680_1.0.2.dsc to build-master.raspberrypi.org for raspberrypi.
+Successfully uploaded bme680_1.0.2.tar.xz to build-master.raspberrypi.org for raspberrypi.
+Successfully uploaded python-bme680_1.0.2_all.deb to build-master.raspberrypi.org for raspberrypi.
+Successfully uploaded python3-bme680_1.0.2_all.deb to build-master.raspberrypi.org for raspberrypi.
+Successfully uploaded bme680_1.0.2_armhf.changes to build-master.raspberrypi.org for raspberrypi.

packaging/debian/changelog

@@ -1,3 +1,9 @@
+bme680 (1.0.3) stable; urgency=low
+
+  * Merged temperature compensation fix from Bosch's BME680_driver 3.5.3
+
+ -- Phil Howard <phil@pimoroni.com>  Wed, 22 Nov 2017 00:00:00 +0000
+
 bme680 (1.0.2) stable; urgency=low
 
   * Fixed set_gas_heater_temperature to avoid i2c TypeError

packaging/makelog.sh

@@ -39,9 +39,10 @@ inform "seeded debian changelog"
 
 # generate pypi changelog
 
-sed -e "/--/d" -e "s/  \*/\*/" \
+sed -e "/--/d" \
-    -e "s/.*\([0-9].[0-9].[0-9]\).*/\1/" \
+    -e "s/  \*/\*/" \
-    -e '/[0-9].[0-9].[0-9]/ a\
+    -e "s/.*(\([0-9].[0-9].[0-9]\)).*/\1/" \
+    -e '/^[0-9].[0-9].[0-9]$/ a\
 -----' $mainlog | cat -s > $pypilog
 
 version=$(head -n 1 $pypilog)

packaging/testlog.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+
+sed -e "/--/d" \
+    -e "s/  \*/\*/" \
+    -e "s/.*(\([0-9].[0-9].[0-9]\)).*/\1/" \
+    -e '/^[0-9].[0-9].[0-9]$/ a\
+-----' CHANGELOG