Ambient Light Sensor issue with RPi 0w

[Anubis 10545]

Hello everyone,

I have a light sensor from Spakrfun that I've connected to my Raspbery Pi 0w via a breadboard. I've found a code on GitHub that should (theoretically) work with the sensor and allow it to output ambient light values. However, when I run the code, rather than the spiting out the lux values from the sensor, I get the IOError (shown at the very bottom of the code posted below).

- The APDS-9301 light sensor from Sparkfun: https://www.sparkfun.com/products/14350
- The code I’m using from GitHub: https://github.com/iotify/custom-lab/bl ... pds9301.py
- A picture of my breadboard setup: https://s22.postimg.cc/uh5c8n0up/IMG_7946.jpg

Code: Select all

# Python code to read luminosity values from APDS-9301

import smbus
import time
import math
import sys

class adps9300(object):
	bus = None;
	addr = 0x29;
	
	REG_CONTROL        = 0x00
	REG_TIMING         = 0x01
	REG_THRESHLOWLOW   = 0x02
	REG_THRESHLOWHIGH  = 0x03
	REG_THRESHHIGHLOW  = 0x04
	REG_THRESHHIGHHIGH = 0x05
	REG_INTERRUPT      = 0x06
	REG_CRC            = 0x08
	REG_ID             = 0x0A
	REG_DATA0LOW       = 0x0C
	REG_DATA0HIGH      = 0x0D
	REG_DATA1LOW       = 0x0E
	REG_DATA1HIGH      = 0x0F
	
	REG_CONTROL_CMD = 1<<7
	REG_CONTROL_IRQCLEAR = 1<<6
	REG_CONTROL_WORD = 1<<5
	REG_CONTROL_POWER_ON = 0x03
	
	REG_TIMING_GAIN_1  = 0<<4
	REG_TIMING_GAIN_16 = 1<<4
	REG_TIMING_START_CYCLE = 1<<3
	
	REG_TIMING_INTEGRATE_13_7MS = 0
	REG_TIMING_INTEGRATE_101MS = 1
	REG_TIMING_INTEGRATE_402MS = 2
	
	REG_TIMING_SCALE_13_7MS = 0.034
	REG_TIMING_SCALE_101MS = 0.252
	REG_TIMING_SCALE_402MS = 1
	
	_gain = 0
	_integration = 0
	
	 
	def __init__(self):
		self.bus = smbus.SMBus(1);
		self.set_power(True)
		self.set_timing(True, 0);
	
	def set_power(self, on):
		regval = 0
		if on == True:
			regval = self.REG_CONTROL_POWER_ON
		
		self.bus.write_byte_data(self.addr, self.REG_CONTROL | self.REG_CONTROL_CMD, regval); #init
	
	def set_timing(self, highgain, integration):
		print 'Settings: high gain', highgain, 'integration', integration
		regval = 0
		
		if highgain == True:
			regval = regval | self.REG_TIMING_GAIN_16
			self._gain = 1
		else:
			regval = regval | self.REG_TIMING_GAIN_1
			self._gain = 1 / 16.0
		
		if integration == 0:
			regval = regval | self.REG_TIMING_INTEGRATE_13_7MS
			self._integration = self.REG_TIMING_SCALE_13_7MS
		elif integration == 1:
			regval = regval | self.REG_TIMING_INTEGRATE_101MS
			self._integration = self.REG_TIMING_SCALE_101MS
		else:
			regval = regval | self.REG_TIMING_INTEGRATE_402MS
			self._integration = self.REG_TIMING_SCALE_402MS
			
		self.bus.write_byte_data(self.addr, self.REG_TIMING | self.REG_CONTROL_CMD, regval); #init
	
	def read_raw(self):
		ch0 = self.bus.read_word_data(self.addr, self.REG_CONTROL_CMD | self.REG_CONTROL_WORD | self.REG_DATA0LOW); # 0xAC
		ch1 = self.bus.read_word_data(self.addr, self.REG_CONTROL_CMD | self.REG_CONTROL_WORD | self.REG_DATA1LOW); # 0xAE
		return [ch0, ch1];
	
	def read_lux(self):
		ch0, ch1 = self.read_raw();
		return self.calc_lux(ch0, ch1)
	
	def calc_lux(self, ch0, ch1):
		
		ch0 = ch0 / self._gain / self._integration
		ch1 = ch1 / self._gain / self._integration
		
		if ch0 == 0:
			return None
		
		ch0 = float(ch0)
		ch1 = float(ch1)
		
		lux = 0
		
		d = ch1 / ch0
		if ch1 == ch0 == 65535:
			return float('nan') # out of range
		if d > 0 and d <= 0.5:
			lux = 0.0304 * ch0 - 0.062 * ch0 * math.pow(d, 1.4)
		elif d > 0.5 and d <= 0.61:
			lux = 0.0224 * ch0 - 0.031 * ch1
		elif d > 0.61 and d <= 0.80:
			lux = 0.0128 * ch0 - 0.0153 * ch1
		elif d > 0.80 and d <= 1.30:
			lux = 0.00146 * ch0 - 0.00112 * ch1
		elif d > 1.3:
			lux = 0
		
		return lux

		
if __name__ == "__main__":
	try:
		x = adps9300()
		print "Lux value is %s" % x.read_lux()
	except IOError, e:
		print e
		print "Error creating connection to i2c.  This must be run as root"

I've enabled the i2c interface with sudo raspi-config. Using sudo i2cdetect –y l, I get the following, which (I think) shows that a device is connected:

0 1 2 3 4 5 6 7 8 9 a b n d e f
0 __ __ __ __ __ __ __ __ __ __ __ __ __
10 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
20 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
30 __ __ __ __ __ __ __ __ __ 39 __ __ __ __ __ __
40 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
50 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
60 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
70 __ __ __ __ __ __ __ __

I'm still pretty new to Raspberry Pi and Python. I've been going crazy the last few weeks trying to figure out why this isn't working. (Note: I've tried several different codes from GitHub, and none of them work, which leads me to believe it's an issue with the i2c or my setup or something...). Any help would be greatly appreciated!

[bensimmo]

Code: Select all

class adps9300(object):
	bus = None;
	addr = 0x29;

Here change 29 to 39.

[Anubis 10545]

Code: Select all

class adps9300(object):
	bus = None;
	addr = 0x29;

Here change 29 to 39.

Yes, that was the problem. (Also, the line 4th from the bottom should have been x.read_lux() rather than x.read_lx().). Thanks!