Merge pull request #1 from floitsch/review

Minor suggestions. thanks for the review

README.md

@@ -1,6 +1,6 @@
 # SI70xx
 
-**A low level TOIT driver for the Silabs Si70xx/HTU21D  sensor family.**
+A low level TOIT driver for the Silabs Si70xx/HTU21D sensor family.
 
 [ derived and based on the work from https://github.com/toitware/toit-si7006/ ]
 
@@ -24,20 +24,20 @@ A simple usage example.
 ``` toit
 import gpio
 import serial.protocols.i2c as i2c
-import .si70xx show *
+import si70xx show *
 import math
 
 main:
   sda := gpio.Pin 21
   scl := gpio.Pin 22
   bus := i2c.Bus --sda=sda --scl=scl --frequency=100_000
-  i2c_device := bus.device Si70xx.I2C_ADDRESS_40
+  i2c_device := bus.device Si70xx.I2C_ADDRESS
   sensor := Si70xx i2c_device
 
   print "Device Type: $sensor.device_type"
   print "Firmware: $sensor.firmware"
   print "SerialNr#: $sensor.serial_number"
-  
+
   print "Temperature: $(%0.1f sensor.temperature)C"
   print "Humidity: $(sensor.humidity.round)%"
 ```

example/package.lock

@@ -0,0 +1,5 @@
+prefixes:
+  si70xx: ..
+packages:
+  ..:
+    path: ..

example/package.yaml

@@ -0,0 +1,3 @@
+dependencies:
+  si70xx:
+    path: ..

example/si7021.yaml

@@ -10,4 +10,4 @@ entrypoint: si7021_example.toit
 triggers:
   on_install: true
   on_boot: true
-  on_interval: 30s
+  on_interval: 30s

example/si7021_example.toit

@@ -7,16 +7,16 @@ main:
   sda := gpio.Pin 21
   scl := gpio.Pin 22
   bus := i2c.Bus --sda=sda --scl=scl --frequency=100_000
-  i2c_device := bus.device Si70xx.I2C_ADDRESS_40
+  i2c_device := bus.device Si70xx.I2C_ADDRESS
   sensor := Si70xx i2c_device
 
   print "Device Type: $sensor.device_type"
   print "Firmware: $sensor.firmware"
   print "SerialNr#: $sensor.serial_number"
-  
+
   temperature := (sensor.read_temperature)
   humidity := (sensor.read_humidity)
-  
+
   // for dewpoint calculation
   // dew = (bα(T,RH)) / (a - α(T,RH))
   // α(T,RH) = ln(RH/100) + aT/(b+T)
@@ -31,5 +31,5 @@ main:
     "Humidity": "$(humidity.round)",
     "Dewpoint": dew,
   }
-  
-  print THD
+
+  print THD

src/si70xx.toit

@@ -4,29 +4,27 @@ import serial.protocols.i2c as i2c
 import gpio
 
 /**
-Driver for Si70xx Family and the HTU21D Humidity and Temperature Sensor
-SI7006 addr: 0x40, device_id 0x06
-SI7013 addr: 0x41, device_id 0x0D
-SI7020 addr: 0x40, device_id 0x14
-SI7021 addr: 0x40, device_id 0x15
-HTU21D is the same as SI7021
+Driver for Si70xx Family and the HTU21D Humidity and Temperature Sensor.
 */
 
 class Si70xx:
   device_ /i2c.Device
-  static I2C_ADDRESS_40 ::= 0x40
-  static I2C_ADDRESS_41 ::= 0x41
+
+  /** The default I2C address for the Si70xx/HTU21D sensor family. */
+  static I2C_ADDRESS ::= 0x40
+  /** The alternate I2C address for the Si70xx/HTU21D sensor family. */
+  static I2C_ADDRESS_ALT ::= 0x41
 
   constructor .device_:
-  
+
   static DEVICE_TYPE_ ::= {
     0x06 : "Si7006",
     0x13 : "Si7013",
     0x14 : "Si7020",
     0x15 : "Si7021",
     0x22 : "Si7034",
   }
-  
+
   static FIRMWARE_VERSIONS_ ::= {
     0xff : "Version 1.0",
     0x20 : "Version 2.0",
@@ -49,7 +47,7 @@ class Si70xx:
       --if_present=:
         fw = FIRMWARE_VERSIONS_[bytes[0]]
     return fw
-    
+
   /**
   A 64 bit serial number for the sensor.  It is an error if the sensor has a
     serial number that indicates it is not an Si70xx sensor.
@@ -68,8 +66,8 @@ class Si70xx:
     check_crc_ bytes2 [0, 1, 3, 4] 5
     DEVICE_TYPE_.get bytes2[0]
       --if_absent=:
-        throw "Not a supported model type: 0x$(%02x bytes2[0])"
-    
+        throw "Unsupported model type: 0x$(%02x bytes2[0])"
+
     return "$(%016x (bytes1[0] << 56 | bytes1[2] << 48 | bytes1[4] << 40 | bytes1[6] << 32
                    | bytes2[0] << 24 | bytes2[1] << 16 | bytes2[3] << 8 | bytes2[4]) )"
 
@@ -84,7 +82,7 @@ class Si70xx:
         type = "Unknown model type: 0x$(%02x bytes[0])"
       --if_present=:
         type = DEVICE_TYPE_[bytes[0]]
-    
+
     return type
 
   static check_crc_ bytes/ByteArray offsets/List expected/int: