pimatic-bh1750 plugin available

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Hi all,

I just wanted you all to know that I have implemented a plugin for the BH1750 light sensor. The BH1750 is an affordable i2c light intensity sensor. I use it to switch on/off my lights. In my case the differences in weather type (cloudy/sunny) make sunrise/down times unusable.

The plug-in is available as npm package and source at github

I would be happy to receive any comments on the plugin, just let me know!

Cheers, Jos

@Jos-Hendriks
Sounds really interesting. May you could write a tutorial how you built your device. If its not to difficult i like try to rebuild 😁
Thanks for your work.
dk00000

@dk00000 said:

ay you could write a tutorial how you built your device. If its not to difficult i like try to rebuild 😁
Thanks for your work.
dk00000

Really simple. Here is a schematic: https://www.pinterest.com/pin/348817933615254149/
I even have a 6 meter cable between the sensor and the pi, no issues at all!

@Jos-Hendriks
as i read here i have to enabel i2c. i assume that i cant use this device at the same time i use my razberry z-wave daughter card. am i right?
cheers
dk00000

From what I understand the Razberry uses the Raspberry Pi serial port (pin 8 and 10) to communicate. This means that the i2c pins (pin 3 and 5) are not used by the Razberry. This means you can use them yourself. But you do need to find a way to physically connect. I do not know about your electrical/soldering skills, but it is a straightforward job.

@Jos-Hendriks
hi. as you can see on the picture the pins are blocked with the daughterboard. so is there an other way to use both devices? or do you know other light sensors i can use parallel to z-wave board?
btw: i have soldering skills but less electrical skills, so i need help to solder the right cables

You could solder an adapter board where you could plug your z-wave to and have gpio pins or just solder two pins on top of the gpio pins on your z-wave board. Should be of no problem
Or use a bread board where you can plug all onto.

Pin 3 and 5 are the i2c pins

How do I get this plugin listed on http://www.pimatic.org/pages/plugins/?

Cool plugin . I’ve added it to the plugin list.

@Jos-Hendriks hi, it is possible to added this lightsensor similar to the 1wire system.
For more sensors. For example for every shutter.

@Thrusty, The sensor i connected through i2c, which is a bus system. This mean you can connect multiple devices and access them induvidually.

@Jos-Hendriks Thanks, sound like.
I would be control my shutters if sun is shining.

@Jos-Hendriks Very nice! Two things, I would like to suggest:

• The sensor provides different resolution/sensitivity modes while “H-Resolution Mode” (1 lx, 120ms measurement time) seems to be activated by default (which is good). However, the device also provides a “H-Resolution Mode2” (0.5lx, 120ms) which might be interesting for some applications, e.g. in extreme low-light situations. Therefore, it would be nice to have a device configuration property to select the measurement mode. To get this mapped directly to the base driver, it should be named “command”. It may also be interesting to use the “Power Down after measurement” commands.
• As the sensor values may be inaccurate, it would be nice to be able add an “offset” value (value may be positive or negative decimal) to adjust the sensor value. This may be helpful for users who a have calibrated light meter to compare with.

@mwittig Thanks!, I’ll put them on the todo list.

@leader21 It is possible that you write a howto for the BH1750 ?

a howto for this plugin… well it’s not that complicated to handle, isn’t it?
When I have some time next week I will have a look. at the moment I am quite busy.

have a look here. jos has explained all very well!
https://github.com/circuitdb/pimatic-bh1750

@leader21 Hi, I have the bh1750 installed. The manual is a bit confusing because the values ​​are already filled in . But no matter .
The sensor now seems to be working . Unfortunately, it seems but just that. I just get the value 1280LUX displayed in pimatic. And nothing changes . I have the following in my config :

{
      "id": "my-sensor",
      "name": "bh1750 example",
      "class": "BH1750Sensor",
      "device": "/dev/i2c-1",
      "address": "3x23",
      "interval": 10000
    },

What’s wrong , it might be that I do not receive proper measurement?

I have tested the sensor according to this description . With the result that it is working . I get different editions , depending on light intensity . So the wiring is probably correct.

Well that’s an issue that @Jos-Hendriks as the plugin dev has to solve I guess…

Now I have separated the bridge between GND and ADD at BH1750 and get readings. The BH1750 ran most of the day without any problems, but two outs. Twice I got the value 1280LUX displayed. After I separated the VCC contact and reconnected again ran the measurement. Can anyone tell me how to fix this problem to me?

@Thrusty said:

Now I have separated the bridge between GND and ADD

That means you have two seperate GND wires?