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add kickstart pumps to giessomat

Thomas Buck 2 лет назад
Родитель
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4767b717f8
3 измененных файлов: 30 добавлений и 1 удалений
  1. 30
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      input/projects/giessomat.md
  2. Двоичные данные
      static/img/giessomat_gpio_ext.jpg
  3. Двоичные данные
      static/img/giessomat_gpio_ext_small.jpg

+ 30
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input/projects/giessomat.md Просмотреть файл

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 github: https://git.xythobuz.de/thomas/giess-o-mat
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 date: 2021-03-29
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-update: 2022-02-07
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+update: 2022-03-25
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 ---
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 This project [was featured on Hackaday](https://hackaday.com/2021/05/14/automated-watering-machine-has-what-plants-crave-fertilizer/)!
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 The software [has been updated](https://git.xythobuz.de/thomas/giess-o-mat/commit/6de07b6cc9664cf78b337dc4b86d29a61fb20410) to now support 16 I2C GPIO expanders with 8 pins each, for all supported functions (valves, pumps, stirrers, locks).
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 To unlock the doors I [added](https://git.xythobuz.de/thomas/giess-o-mat/commit/70659caf77d655febd31a877d98070db76cb462e) an optional PIN entry function on the start screen of the UI.
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+## Valve Kickstarting Update (March 2022)
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+
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+Right at the beginning, another issue came up with the machine.
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+The gravity-fed outlet valves work fine as planned, as long as the whole length of the outlet hose is primed / filled with water.
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+Then, all the water in the lower part "pulls" downward from gravity, creating a negative pressure differential that sucks the liquid out of the tank.
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+Unfortunately, with enough time between dispensing water, the hose starts slowly emptying into the plant.
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+After enough time passes, all the water up to the highest point of the hose has flowed out.
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+When then trying to dispense more water, nothing happens when opening the valve.
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+The way I worked around that was by using a syringe to suck some air out of the bottom of the hose, at the plants.
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+Not much is needed, only enough to bring the water below the height of the inlet in the tank.
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+
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+This was passable at the beginning.
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+I am physically present at the machine anyway to tell it to start dispensing, so quickly priming the valves was not that much more work.
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+But as the project matures, I'd like to use it to further automate the plant watering, so I had to find a way to fix this problem.
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+The solution comes in the form of more pumps, one connected "in parallel" to each outlet valve.
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+This way, the pumps can run for a couple of seconds at the beginning, to "kick start" the water flow.
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+But because they are pretty noisy, they turn off after 10sec, after which the valves take over with gravity.
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+To connect the pumps, I used more I2C port expanders with relais, as described in the GPIO Expansion Update above.
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+The software [has been updated](https://git.xythobuz.de/thomas/giess-o-mat/commit/4dab9e16f5e5f28c05832694db125513b1513720) to allow setting optional kickstart pins for each outlet valve.
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+
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+<!--%
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+lightgallery([
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+    [ "img/giessomat_gpio_ext.jpg", "GPIO Expansion with valves and pumps" ],
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+])
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+%-->
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+
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 ## Links
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 You can find [all the source code for the device itself](https://git.xythobuz.de/thomas/giess-o-mat) (both the UI and the Controller) as well as the OpenSCAD [design files for the 3D printed parts](https://git.xythobuz.de/thomas/3d-print-designs/src/branch/master/giessomat) on my [Gitea instance](https://git.xythobuz.de).

Двоичные данные
static/img/giessomat_gpio_ext.jpg Просмотреть файл


Двоичные данные
static/img/giessomat_gpio_ext_small.jpg Просмотреть файл


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