add uv sensor veml6070

config.json.template

@@ -25,6 +25,8 @@
 "mcp9808": {"enable": 1},
 "tsl2591":
 {"enable": 1, "port": 1,"address": "0x29"},
+"veml6070":
+{"enable": 1, "port": 1},
 "ads1x15":
 {"enable": 1,"gain": 1,
 "adc":{

demo_6070.py

@@ -0,0 +1,13 @@
+
+import veml6070
+
+if __name__ == '__main__':
+    veml = veml6070.Veml6070()
+    for i in [veml6070.INTEGRATIONTIME_1_2T,
+              veml6070.INTEGRATIONTIME_1T,
+              veml6070.INTEGRATIONTIME_2T,
+              veml6070.INTEGRATIONTIME_4T]:
+        veml.set_integration_time(i)
+        uv_raw = veml.get_uva_light_intensity_raw()
+        uv = veml.get_uva_light_intensity()
+        print "Integration Time setting %d: %f W/(m*m) from raw value %d" % (i, uv, uv_raw)

logger.py

@@ -151,6 +151,26 @@ if "tsl2591" in log_conf:
       channel_names.append("lux")
       channel_info["lux"]={"sensor":"tsl2591","timestamp":0,"i2c":tsl_add}
 
+# config of lux sensor tls2591
+bveml=False
+if "veml6070" in log_conf:
+  bveml=True
+  if "enable" in log_conf['veml6070']:
+    if log_conf['veml6070']['enable'] == 0:
+      bveml=False
+  if bveml:
+    import veml6070
+    veml_port=1
+    if "port" in log_conf['veml6070']:
+      veml_port=int(log_conf['veml6070']['port'])
+    try:
+      veml = veml6070.Veml6070(i2c_bus=veml_port)
+    except:
+      bveml=False
+    else:
+      channel_names.append("uv")
+      channel_info["uv"]={"sensor":"veml6070","timestamp":0,"i2c":0x38}
+
 # config of bme280 sensor
 # use pip install RPi.bme280 for library
 bbme=False
@@ -364,6 +384,12 @@ while a > 1:
     if btls:
       tsl_full,tsl_ir=tsl.get_full_luminosity()
       ch_val[channel_names.index("lux")] = int(1000*tsl.calculate_lux(tsl_full,tsl_ir))
+  # get uv index
+    if bveml:
+      tsl_full,tsl_ir=tsl.get_full_luminosity()
+      veml.set_integration_time(veml6070.INTEGRATIONTIME_1T)
+#      uv_raw = veml.get_uva_light_intensity_raw()
+      ch_val[channel_names.index("uv")] = int(1000*veml.get_uva_light_intensity())
 
 # read adc's
     if badc:

veml6070/__init__.py

@@ -0,0 +1,3 @@
+
+from .veml6070 import Veml6070
+from .veml6070 import INTEGRATIONTIME_1_2T, INTEGRATIONTIME_1T, INTEGRATIONTIME_2T, INTEGRATIONTIME_4T, RSET_240K, RSET_270K, RSET_300K, RSET_600K

veml6070/veml6070.py

@@ -0,0 +1,105 @@
+
+import time
+
+import smbus # pylint: disable=import-error
+
+ADDR_L = 0x38 # 7bit address of the VEML6070 (write, read)
+ADDR_H = 0x39 # 7bit address of the VEML6070 (read)
+
+RSET_240K = 240000
+RSET_270K = 270000
+RSET_300K = 300000
+RSET_600K = 600000
+
+SHUTDOWN_DISABLE = 0x00
+SHUTDOWN_ENABLE = 0x01
+
+INTEGRATIONTIME_1_2T = 0x00
+INTEGRATIONTIME_1T = 0x01
+INTEGRATIONTIME_2T = 0x02
+INTEGRATIONTIME_4T = 0x03
+
+class Veml6070(object):
+
+    def __init__(self, i2c_bus=1, sensor_address=ADDR_L, rset=RSET_270K, integration_time=INTEGRATIONTIME_1T):
+        self.bus = smbus.SMBus(i2c_bus)
+        self.sendor_address = sensor_address
+        self.rset = rset
+        self.shutdown = SHUTDOWN_DISABLE # before set_integration_time()
+        self.set_integration_time(integration_time)
+        self.disable()
+
+    def set_integration_time(self, integration_time):
+        self.integration_time = integration_time
+        self.bus.write_byte(self.sendor_address, self.get_command_byte())
+        # constant offset determined experimentally to allow sensor to readjust
+        time.sleep(0.2)
+
+    def get_integration_time(self):
+        return self.integration_time
+
+    def enable(self):
+        self.shutdown = SHUTDOWN_DISABLE
+        self.bus.write_byte(self.sendor_address, self.get_command_byte())
+
+    def disable(self):
+        self.shutdown = SHUTDOWN_ENABLE
+        self.bus.write_byte(self.sendor_address, self.get_command_byte())
+
+    def get_uva_light_intensity_raw(self):
+        self.enable()
+        # wait two times the refresh time to allow completion of a previous cycle with old settings (worst case)
+        time.sleep(self.get_refresh_time()*2)
+        msb = self.bus.read_byte(self.sendor_address+(ADDR_H-ADDR_L))
+        lsb = self.bus.read_byte(self.sendor_address)
+        self.disable()
+        return (msb << 8) | lsb
+
+    def get_uva_light_intensity(self):
+        uv = self.get_uva_light_intensity_raw()
+        return uv * self.get_uva_light_sensitivity()
+
+    def get_command_byte(self):
+        """
+        assembles the command byte for the current state
+        """
+        cmd = (self.shutdown & 0x01) << 0 # SD
+        cmd = (self.integration_time & 0x03) << 2 # IT
+        cmd = ((cmd | 0x02) & 0x3F) # reserved bits
+        return cmd
+
+    def get_refresh_time(self):
+        """
+        returns time needed to perform a complete measurement using current settings (in s)
+        """
+        case_refresh_rset = {
+            RSET_240K: 0.1,
+            RSET_270K: 0.1125,
+            RSET_300K: 0.125,
+            RSET_600K: 0.25
+        }
+        case_refresh_it = {
+            INTEGRATIONTIME_1_2T: 0.5,
+            INTEGRATIONTIME_1T: 1,
+            INTEGRATIONTIME_2T: 2,
+            INTEGRATIONTIME_4T: 4
+        }
+        return case_refresh_rset[self.rset] * case_refresh_it[self.integration_time]
+
+    def get_uva_light_sensitivity(self):
+        """
+        returns UVA light sensitivity in W/(m*m)/step
+        """
+        case_sens_rset = {
+            RSET_240K: 0.05,
+            RSET_270K: 0.05625,
+            RSET_300K: 0.0625,
+            RSET_600K: 0.125
+        }
+        case_sens_it = {
+            INTEGRATIONTIME_1_2T: 0.5,
+            INTEGRATIONTIME_1T: 1,
+            INTEGRATIONTIME_2T: 2,
+            INTEGRATIONTIME_4T: 4
+        }
+        return case_sens_rset[self.rset] / case_sens_it[self.integration_time]