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ESP32 Wemos D1 Mini – Sprinkler Controller Open Source

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Re: ESP32 Wemos D1 Mini – Sprinkler Controller Open Source

#21

Post by wayfinder »

intpx wrote: post #13
eternityforest wrote: post #11

Earlier quoted context omitted.

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.

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,…

No, DC is more efficient over long distances than AC. AC transmission has huge losses due to capacitive effects caused by the alternating current.

AC also has WORSE voltage drop than DC because it exhibits something called the skin effect that causes the middle of your cable to not be used as much to carry current.

Tesla triumphed over Edison because we didn’t have the technology to step between voltages back then. DC transformers are still incredibly expensive. AC transformers are coils of wires.

Re: ESP32 Wemos D1 Mini – Sprinkler Controller Open Source

#22

Post by WaxProlix »

I've been playing around with a few ESP32 projects recently and my biggest complaint is that it's hard to get off the ground with even the most basic peripherals. Like, an SD card reader - you need to get your own SPI reader and solder it in yourself.

Maybe I'm just spoiled but it feels like I shouldn't have to go design something on PCBWay.com to get an esp with any memory above the 4MB flash.

Still, really powerful cool devices for their form factor and power needs.

Re: ESP32 Wemos D1 Mini – Sprinkler Controller Open Source

#23

Post by sokoloff »

londons_explore wrote: post #16

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…

I have three running around the house for years and I’ve never noticed one being offline. I just spot-checked them all and all are online.

Re: ESP32 Wemos D1 Mini – Sprinkler Controller Open Source

#24

Post by ahaucnx »

londons_explore wrote: post #16

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…

We used a few thousand of the D1 mini (ESP8266) for our air quality monitor kits and had a couple of issues.

On some of them the WiFi would not work at all. Kind of like the onboard antenna was not properly connected. Other died after a few months without any special reason that we were aware of.

Another problem with these boards is that you do not know exactly the specs of the other components. For example we got different rated voltage regulators (5v to 3.3) that caused some issues because sensors we put on the 3.3v did have higher requirements.

Interestingly we had more issues with the "original" ones than the clones. I actually wrote a small blog post about it [1].

Another issue is that it is difficult to get proper ROHS and REACH certifications for these modules. This makes it difficult if you want to use them in a finished and certified product.

All of these issues added up and we made the switch away from the module and now put the ESP32-C3-MINI directly onto the PCBs of our indoor and outdoor air quality monitors. Together with an external hardware watchdog, this seems to pretty much eliminate all issues we had. If you are interested in the shematics, its all open source [2].

[1] https://www.airgradient.com/blog/d1-mimi/

[2] https://www.airgradient.com/open-airgradient/instructions/ov...

Re: ESP32 Wemos D1 Mini – Sprinkler Controller Open Source

#25

Post by mianos »

I have many similar projects. By far, the hardest part for anything I actually want to share is user friendly wifi provisioning. The rest is easy, displays, devices and power supply. (I have 5 different HL-tech radars on boards with 3 different displays, one using LVGL).

I am using the app based Espressive app based provisioning now and it's the best of the lot but still flakey on the Risk V chips like much of the IDF/Arduino wrappers. It's a hard problem.

Most of it works pretty well with the Extensa core so I suggest sticking with those.

Re: ESP32 Wemos D1 Mini – Sprinkler Controller Open Source

#26

Post by thenewwazoo »

mianos wrote: post #25

I have many similar projects. By far, the hardest part for anything I actually want to share is user friendly wifi provisioning. The rest is easy, displays, devices and power supply. (I have 5 different HL-tech radars on boards with 3 different displays, one using LVGL). I am using the app based Espressive app based provisioning now and it's the best of the lot but still flakey on the Risk V chips like much of the ID…

I’m in the thick of implementing Improv support, which uses Web Serial to configure WiFi. It’s worth checking out.

http://improv-wifi.com/

Re: ESP32 Wemos D1 Mini – Sprinkler Controller Open Source

#27

Post by analog31 »

f_devd wrote: post #6

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.

An amusing feature of solenoid valves is that the inductance increases as the plunger is pulled into the coil. When driven by AC, it causes an initial "kick" of current that gets the slider moving, followed by a lower holding current. Thus it fortuitously optimizes the current budget of the power supply.

Also, when a plunger gets stuck, the coil continues to draw a lot of current, and could burn up. This is a failure mode of solenoid valves in industrial processes. You can get DC solenoid valves, but the coils are bigger and they're more expensive. It means you shouldn't run an AC solenoid on DC unless you're really thinking hard about what you're doing.

And speaking of failure modes, another amusing feature of solenoid valve systems is the sheer number of ways that they can fail. One thing that's always counterintuitive to beginners is that a valve or its control circuit (or firmware) can get stuck in the "on" position. This is true of solid state and mechanical relays. A well engineered system plans for this possibility. "Stuck" could mean releasing a lot of energy (e.g., if controlling a heater or motor), or flooding your garden, or your house.

Re: ESP32 Wemos D1 Mini – Sprinkler Controller Open Source

#28

Post by doubleg72 »

londons_explore wrote: post #16

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…

I’ve had a couple Wemos D1 mini for garage door controls and they have just worked without issue for 3 years now.

Re: ESP32 Wemos D1 Mini – Sprinkler Controller Open Source

#29

Post by mianos »

thenewwazoo wrote: post #26
mianos wrote: post #25

I have many similar projects. By far, the hardest part for anything I actually want to share is user friendly wifi provisioning. The rest is easy, displays, devices and power supply. (I have 5 different HL-tech radars on boards with 3 different displays, one using LVGL). I am using the app based Espressive app based provisioning now and it's the best of the lot but still flakey on the Risk V chips like much of the ID…

I’m in the thick of implementing Improv support, which uses Web Serial to configure WiFi. It’s worth checking out. http://improv-wifi.com/

I'll add it and give it a try. Thanks.

Re: ESP32 Wemos D1 Mini – Sprinkler Controller Open Source

#30

Post by 15155 »

mianos wrote: post #25

I have many similar projects. By far, the hardest part for anything I actually want to share is user friendly wifi provisioning. The rest is easy, displays, devices and power supply. (I have 5 different HL-tech radars on boards with 3 different displays, one using LVGL). I am using the app based Espressive app based provisioning now and it's the best of the lot but still flakey on the Risk V chips like much of the ID…

NXP and STM make NFCI2C EEPROM chips that are https://www.nxp.com/products/rfid-nfc/nfc-hf/connected-nfc-t...

https://www.st.com/en/nfc/st25dv-i2c-series-dynamic-nfc-tags...

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