[HN Gopher] ESP32 Wemos D1 Mini - Sprinkler Controller Open Source
       ___________________________________________________________________
        
       ESP32 Wemos D1 Mini - Sprinkler Controller Open Source
        
       Author : pcbmaker20
       Score  : 57 points
       Date   : 2023-10-28 16:55 UTC (6 hours ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | cxcorp wrote:
       | I don't think there's a D1-ESP32 board? The D1 Mini is Wemos'
       | ESP8266 board. They do have ESP32 boards with the same footprint,
       | but those are not D1 Mini but S2 Mini, S3 Mini and C3 Mini,
       | depending on whether it's ESP32-S2/-S3/-C3.
        
         | oldgradstudent wrote:
         | That's what I thought as well, it is not available at:
         | 
         | https://www.wemos.cc/en/latest/index.html
         | 
         | But the specific board from the post can be bought on Amazon:
         | 
         | https://www.amazon.com/CANADUINO-WEMOS-Minikit-240MHz-Blueto...
        
         | heffer wrote:
         | You'll find many varieties of boards with different SoCs being
         | sold mentioning the D1 Mini in their model number or product
         | description, as it initially defined the form-factor being
         | referred to. Similar to the ESP-12F, which you can also get
         | with ESP32 SoCs, if you want, even though the ESP-12F
         | originally is an ESP8266 board.
        
         | t0mas88 wrote:
         | Indeed, there is no D1-ESP32 from Wemos. It's a name used by
         | several non-Wemos clones that have an ESP32 chip in a module
         | form factor that is compatible with the original Wemos D1 mini.
         | 
         | The challenge is that these modules are not all the same. The
         | differences are for example in the voltage regulator and how
         | much current you can draw from it. Which can make something
         | work fine with one "D1-ESP32" while not working with another.
        
       | f_devd wrote:
       | 24V AC to me seems like a strange choice when using DC-DC power
       | supplies allows for using any external adapter, including USB PD,
       | without the need for a loose transformer.
        
         | KANahas wrote:
         | 24 VAC is a common voltage for irrigation control, which is
         | likely why they chose to use it.
        
           | conk wrote:
           | Agreed and it's far easier to turn ac into dc than the other
           | way around
        
         | eternityforest wrote:
         | A relic of the ancient days before everything ran on tiny
         | switching converters! There's tons of 24Vac stuff that
         | unfortunately doesn't seem to be interested in switching
         | anytime soon.
         | 
         | Also, AC is easier to switch with physical switches, and
         | there's a ton of stuff still using physical relays at low
         | voltage. It would be nice to go DC but there seems to be
         | inertia.
        
           | intpx wrote:
           | I think there is more to it than that-- AC lets you move
           | current over longer wires without voltage drop or having to
           | use really thick wire. This is why Tesla triumphed over
           | Edison. Honestly, there are a ton of applications that could
           | benefit from low voltage AC that don't leverage it because DC
           | is king in on the test bench and that inertia creates the
           | need for klunky workarounds to overcome its deficiencies in
           | large, long series circuits.
        
           | londons_explore wrote:
           | Worth noting that nearly everything that claims to run from
           | 24 Vac also runs from 5Vdc. Nearly everything modern has a
           | little circuit board which just detects 'voltage' or 'no
           | voltage'.
           | 
           | The exception is 'dumb' solenoids, valves, pumps etc, which
           | are actually powered by the 24Vac.
        
       | amluto wrote:
       | For a classy sprinkler controller, you want 24VAC relay outputs
       | with current monitoring, and you also want a pulse counting input
       | for a flow sensor. Bonus points for rain gauge inputs and some
       | way to collect evapotranspiration data.
        
       | bobsmooth wrote:
       | You can get ESP-controlled relay boards on aliexpress.
        
       | intpx wrote:
       | Apart from the fact that sprinkler systems are almost always
       | 24VAC and every commercial sprinkler controller I have ever used
       | or investigated use optocouplers/fets/triacs I don't really have
       | a good reason to get irritated by homebrew designs that use
       | relays, but I do get irritated. I think the irritation comes from
       | wanting to really learn-by-copying how to design these circuits
       | and many hours searching for exemplars and reading datasheets
       | left me pretty confounded (though most of this was during the
       | great supply chain squeeze so I couldn't find the right combos of
       | triacs and optocouplers ins stock and the datasheets led me to
       | believe that subbing out a non zero cross would probably be a
       | problem, or not being able to find logic level triacs)
        
       | londons_explore wrote:
       | Anyone else have reliability issues with the ESP32?
       | 
       | I have a few of them connected to various wifi networks, and
       | after a couple of years they always seem to disconnect and need a
       | power cycle before they'll reconnect.
       | 
       | I understand they might lose the wifi connection, or their DHCP
       | lease, or there might be interference, or something blasts too
       | many packets at them, or a TCP connection hangs or gets RST...
       | But after any of those, I expect them to recover, reconnect, and
       | continue working. However, even a hello world web server on ESP32
       | seems unable to do that.
       | 
       | However, it's really hard to track down bugs that only happen
       | once a year when I only have ~10 of these devices.
        
         | ahepp wrote:
         | You could set up a watchdog of some sort that reboots the
         | system if it can't connect to the internet.
        
       ___________________________________________________________________
       (page generated 2023-10-28 23:00 UTC)