Set the device in continuous mode

README.md

@@ -4,7 +4,7 @@ Driver for the Sensirion SCD30 sensor module, for monitoring CO2, temperature, a
 
 ## Usage
 
-Installation: `toit pkg install github.com/qvisten999/scd30`
+Installation: `toit.pkg install github.com/qvisten999/scd30`
 
 ```
 import scd30

examples/EXAMPLES_LICENSE

@@ -0,0 +1,14 @@
+Zero-Clause BSD License
+
+Copyright (C) 2021 Toitware ApS
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.

examples/package.lock

@@ -0,0 +1,5 @@
+prefixes:
+  scd30: ..
+packages:
+  ..:
+    path: ..

examples/package.yaml

@@ -0,0 +1,3 @@
+dependencies:
+  scd30:
+    path: ..

examples/room.toit

@@ -1,6 +1,6 @@
-// Copyright (C) 2021 Toitware ApS. All rights reserved.
-// Use of this source code is governed by a MIT-style license that can be found
-// in the LICENSE file.
+// Copyright (C) 2022 Toitware ApS. All rights reserved.
+// Use of this source code is governed by a Zero-Clause BSD license that can
+// be found in the EXAMPLES_LICENSE file.
 
 /**
 Small example to show the use of the CO2 sensor.
@@ -15,9 +15,9 @@ The ESP32 pin connection to the SCD30 sensor is as follows:
 
 import gpio
 import i2c
-import ..src.scd30
+import scd30 show Scd30
 
-co2_level_ := 0.0
+co2_level := 0.0
 
 main:
   bus := i2c.Bus
@@ -28,9 +28,11 @@ main:
   scd30 := Scd30 device
 
   while true:
-    co2_level_ = scd30.read.co2
-    if co2_level_ > 2000:
-      print "Open your window"
+    reading := scd30.read
+    if reading.co2 > 2000:
+      print "Open your window:     $(reading.co2.to_int)ppm"
     else:
-      print "CO2 level is healthy"
-    sleep --ms=60000
+      print "CO2 level is healthy: $(reading.co2.to_int)ppm"
+    print "Temperature:          $(%.1f reading.temperature)ºC"
+    print "Humidity:             $(%.1f reading.humidity)%"
+    sleep --ms=6000

src/driver.toit

@@ -1,4 +1,4 @@
-// Copyright (C) 2021 Toitware ApS. All rights reserved.
+// Copyright (C) 2022 Toitware ApS. All rights reserved.
 // Use of this source code is governed by an MIT-style license that can be
 // found in the LICENSE file.
 
@@ -21,11 +21,20 @@ class Scd30:
   // Available commands.
   static COMMAND_GET_DATA_READY_ ::= #[0x02, 0x02]
   static COMMAND_READ_MEASUREMENT_ ::= #[0x03, 0x00]
+  static COMMAND_SET_CONTINUOUS_AND_PRESSURE_ ::= #[0x00, 0x10]
 
-  device_/serial.Device ::= ?
+  device_/serial.Device
+  pressure_/int := ?
 
-  constructor device/serial.Device:
+  /**
+  Creates a driver and initializes the ambient pressure (in millibar
+    or hectopascal).
+  */
+  constructor device/serial.Device --pressure/int=1013:
     device_ = device
+    if not 0 < pressure < 0x10000: throw "OUT_OF_RANGE"
+    pressure_ = pressure
+    set_pressure_
 
   /**
   Returns whether data is ready.
@@ -42,6 +51,20 @@ class Scd30:
       if i == 100: throw "Device is not getting ready."
       sleep --ms=20
 
+  pressure= value/int:
+    pressure_ = value
+    set_pressure_
+
+  set_pressure_ -> none:
+    // Set continuous mode with the given (or default) air pressure.
+    pressure_bytes := ByteArray 2
+    binary.BIG_ENDIAN.put_int16 pressure_bytes 0 pressure_
+    command := COMMAND_SET_CONTINUOUS_AND_PRESSURE_ + pressure_bytes + #[compute_crc8_ pressure_bytes]
+    device_.write command
+
+  pressure -> int:
+    return pressure_
+
   /**
   Reads the measurements from the sensor.
   Waits until data is available and returns an object containing the CO2, temperature and humidity.