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    mwalker

    @mwalker

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    Best posts made by mwalker

    • RE: Round water tank level sensor

      @tango156157 no worries. Declare waterAvail as a float:

      float waterAvail;
      

      Then when calling set on msgVolume just add a second argument, an int with the number of decimal places you want (I've used 3 which will get you to millilitre precision):

      send(msgVolume.set(waterAvail, 3));
      
      posted in My Project
      mwalker
      mwalker
    • RE: Current Sensing?

      @scalz the jeelabs post is interesting. When I was using an LM393 module with a LDR I was unable to detect the pulses coming from my meter (later established as 15ms). Reading that article it seems that was because of inadequate light proofing (the meter is shaded, but outdoors), but lacking any sort of test equipment, it's interesting to see his oscilloscope tracings of the response of the LDR to a pulse. Thanks for linking it.

      posted in Hardware
      mwalker
      mwalker

    Latest posts made by mwalker

    • RE: Round water tank level sensor

      @tango156157 no worries. Declare waterAvail as a float:

      float waterAvail;
      

      Then when calling set on msgVolume just add a second argument, an int with the number of decimal places you want (I've used 3 which will get you to millilitre precision):

      send(msgVolume.set(waterAvail, 3));
      
      posted in My Project
      mwalker
      mwalker
    • RE: Round water tank level sensor

      My C is a bit rusty, I'm just getting back into this stuff, but your issues seem to be related to ints versus floats, and that's distracting you from your actual calculations. From what I can see most your tank can hold with a radius of 5.8cm and a height of up to 10cm is just over one litre. As you are casting the result to an int then you are only ever going to be able to get two values for waterAvail, 0 or 1.

      You could pass back the capacity in ml instead, or it looks like you need to pass a second argument, decimals, to the msgVolume.set function, to specify how many decimal points need to be sent with the float.

      posted in My Project
      mwalker
      mwalker
    • RE: Housing/Box for ESP8266Wlan Gateway

      The Wemos D1 Mini Pro also has a connector for an external antenna.

      https://www.aliexpress.com/item/WEMOS-D1-mini-Pro-16M-bytes-external-antenna-connector-ESP8266-WIFI-Internet-of-Things-development-board/32724692514.html

      Mine are still on the way so I haven't had a play with them yet.

      posted in Enclosures / 3D Printing
      mwalker
      mwalker
    • RE: Current Sensing?

      @scalz the jeelabs post is interesting. When I was using an LM393 module with a LDR I was unable to detect the pulses coming from my meter (later established as 15ms). Reading that article it seems that was because of inadequate light proofing (the meter is shaded, but outdoors), but lacking any sort of test equipment, it's interesting to see his oscilloscope tracings of the response of the LDR to a pulse. Thanks for linking it.

      posted in Hardware
      mwalker
      mwalker
    • RE: Current Sensing?

      @Samuel235 sounds good.

      More digging identified the openenergymonitor sensor is a rebadged unit manufactured in China:

      https://community.openenergymonitor.org/t/directly-connecting-to-optical-pulse-counter-with-rpi/1294/2

      The link doesn't work but it is in the Internet archive, they have a (fuzzy) photo of the internals at right at the bottom:

      http://web.archive.org/web/20160819224835/https://openenergymonitor.org/emon/opticalpulsesensor

      posted in Hardware
      mwalker
      mwalker
    • RE: Current Sensing?

      Yes, I imagine a requirement to monitor 9 or 10 separate meters at a single location is a bit of a one off, but I'll be definitely interested in what you come up with to see if I can utilise it. I expect I will be using an ESP8266 based board for the micro controller part as power supply is not an issue, and I have wifi available.

      While researching bits and pieces across the internet I came across:

      https://openenergymonitor.org/forum-archive/node/10707.html

      which I thought may be of interest. It seems they are flashing the LED from a microcontroller output, which is an interesting way of proving that the overall system is working.

      posted in Hardware
      mwalker
      mwalker
    • RE: Current Sensing?

      @Samuel235 I'm a fair way away from anywhere in Australia, so it may not be worth it, but thank you.

      For connectors I have been leaning towards them being captive on the sensor end, I was looking at RJ45 for the other end, if only because I thought I could repurpose the connector bank and case from a cheap or surplus hub/switch/router.

      posted in Hardware
      mwalker
      mwalker
    • RE: Current Sensing?

      It looks good @Samuel235, having the detector recessed in a cavity in order to reduce the impact of ambient light isn't something that I had considered, I guess because I was mainly thinking about an off the shelf enclosure, or repurposing some other type of container, i.e. this, but I like these designs a lot better.

      I was able to use a cheap logic analyser with sigrok to work out the pulse time on my meter, and I am in the midst of designing a test rig using WS2812 led strip and a separate microcontroller in order to be able to test my pulse detection code when more of the LM393 modules arrive. One location I need to use this system has ten meters, and another has nine meters, so I need to have a good test rig to make sure that my system won't be dropping pulses.

      posted in Hardware
      mwalker
      mwalker
    • RE: 💬 Window Sensor with Sensebender (high WAF)

      Thanks Michiel, I recently ordered the same unit with the plan to modify it to make an alarm for a cool room door, having a delay before it sounds, then falling back to send off a message if no one responds, your internal photos show that this should be possible.

      posted in OpenHardware.io
      mwalker
      mwalker
    • RE: Current Sensing?

      These look great, I have been working on something similar, for now just using an LM393 module with a phototransistor (or it could be a photodiode, I'm not sure). Initial experiments with a light dependent resistor LM393 module were not successful, its ramp up time was too long for what turned out to be the 15ms pulse time on my electricity meter (3200 pulses per kWh).

      At present I am just using Blu-Tack to provide light isolation (my meter is mounted outside on the front porch) but I was looking at a similar enclosure. I have ordered some Velcro dots off eBay for mounting and have been looking at some enclosures but the ones I see here look much better than anything I have found so far.

      @Samuel235 with your design I was thinking it might make more sense mechanically if the wire is hanging down to have it exiting the enclosure as close as possible to the plane of the mounting point so that as much of the force it is exerting is as a shear which Velcro is good at holding.

      I have also ordered some other parts to try replacing the LDR on my original LM393 module, based on a combination of local availability, price, and wavelength and angular sensitivity. The two I choose are the SFH213 photodiode (wide wavelength, 10º angular) and the SFH309 phototransistor (full spectrum, 24º angular). I'm just getting back into electronics after many years so I still have to pull out the soldering iron and get a workbench set up to try these out.

      posted in Hardware
      mwalker
      mwalker