MPL115A2 calculating coefficients

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kkkkkbruce
 
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Re: MPL115A2 calculating coefficients

Post by kkkkkbruce »

Hi tscott,

Just a quick idea, have you activated the I2C hardware on your pi? Check out adafruits-raspberry-pi-lesson-4-gpio-setup, it has a section on setting it up to work with I2C.

Kev

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tscott
 
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Re: MPL115A2 calculating coefficients

Post by tscott »

YES! That was it. Thank you so much!

jails
 
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Re: MPL115A2 calculating coefficients

Post by jails »

Hi guys,

Much like gvsu, I'm also getting issues with the testcode.py file.

I've used the "Select Code" to paste the codes to files using nano in the terminal. I've named them MPL115A2_class.py and testcode.py (just like kkkkkbruce told gvsu). I've posted a copy of Adafruit_I2C.py in the same folder as these 2.

When trying to run testcode.py I get:

File "./testcode.py", line 9
SyntaxError: Non-ASCII character '\xc2' in file ./testcode.py on line 9, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details

I tried adding # -*- coding: utf-8 -*- and I get:

File "./testcode.py", line 10
rList = mp.getPT()
^
SyntaxError: invalid syntax

Any ideas on what the issue might be?

jails
 
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Re: MPL115A2 calculating coefficients

Post by jails »

Alright so I found the issue, apparently strange characters were placed inside the system when pasting.
I switched to connecting to the RPi through my windows computer using Putty.

I also had to make changes to the MPL115A2_class.py. I kept getting errors because of the self.wakeup():

Traceback (most recent call last):
File "./testcode.py", line 9, in <module>
rList = mp.getPT()
File "/home/pi/Kim/MPL115A2_class.py", line 85, in getPT
self.wakeup() # Start conversion
AttributeError: MPL115A2 instance has no attribute 'wakeup'

However these issues were cleared by removing self.wakeup() from the code.

Kano_XIX
 
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Re: MPL115A2 calculating coefficients

Post by Kano_XIX »

HI
I new whit the raspberry a I have some problems whit the programation, when i compile the program, I had an error
_MPL115A2_Padc_MSB = (0x00)
IndentationError: unindent does not mach any outer indentation level
what can I do for fixed?

crow90
 
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Re: MPL115A2 calculating coefficients

Post by crow90 »

Hi all,

New to this but with your help I have got my sensor working (somewhat anyway) with my RPi. However, when I run the tester posted earlier I get "Error accessing 0x60: Check your I2C address" printed out five times before the temperature and pressure values. The temperature and pressure values are way wrong too. The Pressure is 440hPa and the temperature is -73C any idea what could be going wrong? I haven't changed any of the code from what was posted here.

Thanks

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kkkkkbruce
 
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Re: MPL115A2 calculating coefficients

Post by kkkkkbruce »

Hi crow90

One thing that pops into my mind is how up to date is your clone of the Adafruit i2c code? I got my MPL115A2 out again the other day and when I first tried it I also got a bunch of i2c errors, but after getting a fresh clone of the Adafruit-Raspberry-Pi-Python-Code it worked fine.

Kev

crow90
 
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Re: MPL115A2 calculating coefficients

Post by crow90 »

Hi Kev,

I just installed everything today so everything should be up to date but I'll try reinstalling the adafruit i2c code. I am new to this but have some experience with programming. I find it really odd that five error messages would display and then a results (a wrong one mind you) even tho there is no loop...

thanks

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kkkkkbruce
 
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Re: MPL115A2 calculating coefficients

Post by kkkkkbruce »

Another thought I had was that it could be a loose connection to the Pi giving trouble. Have you run the "sudo i2cdetect -y 1" does the device show up there correctly?

crow90
 
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Re: MPL115A2 calculating coefficients

Post by crow90 »

I am not sure what correct is. But this is what I get.

pi@raspberrypi ~ $ sudo i2cdetect -y 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

I don't have a soldering iron (yet) so I just placed the chip on the pins it seemed like it made a reasonable connection but maybe not. I'll have to try fixing that and maybe my problems will be fixed.

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kkkkkbruce
 
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Re: MPL115A2 calculating coefficients

Post by kkkkkbruce »

ok, you used:

Code: Select all

sudo i2cdetect -y 0
are you sure you don't need?

Code: Select all

sudo i2cdetect -y 1
The only difference is the 1 at the end instead of a 0

You should see in the 0x60 column/row a 60 and not -- if it is detecting the chip correctly.

It should look like this:

Code: Select all

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: 60 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

crow90
 
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Re: MPL115A2 calculating coefficients

Post by crow90 »

Thanks for your suggestions. It was a loose connection in the end. I fixed it and all seems to be working now :-)

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