PWM to control a growlight -- Brief!

ESPHome
1

I know these PWM questions abound, but as a newbie I found they left lingering questions. A brief summation:

  1. Wife’s growlights (Mars Hydro TS1000 for the curious) take a 0-10V input (over RJ11) to control the LED driver;
  2. Saw opportunity to learn ESPhome (some experience with WLED) and thought I could adapt 3.3V PWM from ESP32 (LEDC platform) to 0-10V to control the lights remotely;
  3. Much faffing later, bought this (https://www.amazon.com/DollaTek-0-100-Signal-Voltage-Convert/dp/B07DJ5JQR4) and tested.
  4. Sorta works; can’t get the top end I want (100% only pushes it to 9V) but to me it seems sound. Added a level shifter to nudge the 3.3V pwm signal to 5V. No change.

So is this the right way to go about this? Are there simpler solutions? Am I wriggling about in basically the right territory?

Justin

2

Hey Justin and everyone, who is interested in this topic!
I am also a tinkerer, and I tried a quite similar setup, except that I am using an ESP 8266.

The way you have chosen is the way I have found out indipendentally, so this is the way to go, I think.

The reason, why you cannot go for the full 10 V seems to be the power source you are using, but not on the PWM side. As far as I have heard, you must have at least 12 V, better 14 V in order to get the 10 V.
I will do my own tests soon and report here.

Maybe you can try also and tell, if it works?

Best,
Sebastian

3

The pwm out from an esp is 3.3v max. You will need a 12volt source to send the signal to the light and a digital to anolog converters.

https://www.amazon.com/Signal-Voltage-Converter-Digital-Analog-Industrial/dp/B08CRKRBX4

4

I dont understand why your using a voltage to pwm converter?

If you are going direct to the +/- on the light then this converter is the wrong component. The worst part is other people are encouraging it!

The esp outputs pwm at 3.3v. Your lights are 10v? Are you sure it isnt 12? 10 seems odd. Not impossible nut, odd.

You only need a mosfet to control the 10-12v pwm lights.
Depending on how many lights you have, tbese come in 1 or 4 channel. If you need more than that, you can use something like the PCA9685.

You ha

https://www.amazon.com/Anmbest-High-Power-Adjustment-Electronic-Brightness/dp/B08SJQTQ4Y/ref=mp_s_a_1_3?crid=201GES7A9OHUP&keywords=mosfet%2Bmodule&qid=1707045929&sprefix=mosfet%2Bmodule%2Caps%2C188&sr=8-3&th=1&psc=1

https://www.amazon.com/Anmbest-High-Power-Adjustment-Electronic-Brightness/dp/B07NWD8W26/ref=mp_s_a_1_3?crid=201GES7A9OHUP&keywords=mosfet+module&qid=1707045929&sprefix=mosfet+module%2Caps%2C188&sr=8-3

5

A digital to analog converter?? How do you figure that?

You dont and wouldnt use a DAC to control some 12v led’s, thats silly and wont even work right without extra components.

All you have to do is read the specifications for the Analog to pwm module and it should be pretty obvious, that isnt what those are intended to be used for…

It works by sending 0 - 5v and the module converts that to 0% - 100% pwm, right? To turn the lights on 100% you need to send it 5v. Where and how are you sending it 5v and everything between 5v and 0v from a 3.3v esp32 gpio?

The answer is, you’re not going to… not without a bunch of extra circuits.

The other clue you must have missed is, there arent any current/amp ratings for that module. How much of a load can it drive? 500mAh?, 1Amp?, 2Amp? 10Amp?
It cant, its only meant for converting and sending out data/control signals to whatever device is actually driving the LED’, motor, or whatever. This isnt meant to drive any kind of load.

To drive LED’s from an esp8266/esp32 or any other microcontroller, you just need some mosfets if they use pwm and are NOT addressable led’s.

You can think of mosfets similar to a relay. They can both use a small voltage to control a much larger voltage. Where they differ though is a relay can only turn something On or Off. A mosfet can do that but, it can also be controlled to Open or Close a certain amount based on how much voltage you apply to its base(Just like PWM). For example you can turn something on 50% if you needed where a relay is only 100% On or 100% Off.

Also, you shouldn’t answer peoples questions and tell them what “they need” if you have no idea at all what they need. Are you just trying to get someone to waste their time and money?

Heres a little guide for using mosfets to control lights, motors, actuators, solenoids, etc, etc. Mosfets are used for lots of stuff.

https://www.amazon.com/Anmbest-High-Power-Adjustment-Electronic-Brightness/dp/B07NWD8W26/ref=mp_s_a_1_3?crid=201GES7A9OHUP&keywords=mosfet+module&qid=1707047188&sprefix=mosfet+module%2Caps%2C188&sr=8-3

6

From what I’ve come across grow lights will accept 0-10v, pwm or resistive. Here’s the cut sheet for my driver. I just assumed it was standard to accept all 3.

Screenshot 2024-02-04 080357
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iirc the 10v line need 2ma to operate. I had a converter like that off an esp32 with 12v from a cpu power supply and used it to dim 3 grow lights without a problem

I’ll also add grow light dimmers is often a separate 3 party controller 0-10v has been an industry standard for along time. I assumed grow light manufactures would want to be compatible with the different available dimmers.

7

I may be in the wrong here… It wasnt obvious or clear at all to me that you all were trying to incorporate the factory led driver as well. Then I wondered, why are they using the factory dimmer and doing a bunch of analog/pwm/digital conversions back and forth instead of just putting 1 or multiple mosfets in there which works great, FYI.

Then I reized, those are Constant Current LED’s and a CC driver, which explains the analog/pwm module and you cant dim CC led’s with a mosfet anyway.

Apparently this is just common knowledge if you use grow lights? CC led’s arent really all that common in my experience except a few kinds of lights. My bad

8

From the data sheet it looks like either some are CC/CV and either can be used while others are one or the other?

$279.00?? For an led dimmer controller??

F that. I made my own for all my landscape lighting and accent lighting. It might have all costed only 79$ and does more than just dimming.

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9

That’s a cheap, garbage one. The expensive ones, have true lux sensors that run 300+ just for the sensor, controllers in the thousands.

There is a shit ton of science when it comes to growing especially indoors. Greenhouse automation is big business.

10

I think you were right. The OP sounds like they were trying to provide the analog 0-10v signal to control the existing driver, in which case that Amazon module is not what’s needed, as that seems to be analog to PWM, and you need to do the reverse.

There do seem to be a few different control methods for these things. If it accepts PWM then that’s probably easiest although it’ll probably need to be level shifted. That link in the post above says “10V PWM” but doesn’t specify the thresholds for high and low signals.

If it really needs a 0-10V analog input then it’ll need a level shift and then a capacitor to smooth it.

11

The one I posted is the right configuration. As well as the op’s version being backwards, the 3.3v compatibility is important. That is all you will get from an esp.

Arduino will put out a full 5v signal. A lot of these modules are built with them in mind, so they need a full 5v to put out a signal at 100%

12

What do you consider a, “true lux sensor”. Oh, i know its big business, I worked in the Green industry (not weed) for 15 years. Automation mistakes can completely wreck a growers season or potentially the whole business.

I think I may have been quick to judge here. 95% of the time I see people on here talking about greenhouses or plant watering automation, they usually dont know what theyre doing or talking about. They all want cheap capacitive moisture sensors or grow lights and turn on a pump to water the plants based on some arbitrary moisture level with absolutely no consideration of the type of plant and its watering needs, seasonal needs/changes, or even the concept of deep and infrequent waterings being best.

13

The standard “lux” sensors that you buy from adafruit, ali express ect are not lux sensors. They are all relative.

Lux is defined unit, not something that can vary. True lux sensor gives you actual lux readings. They’re also common in photography.

It seems they are called illuminance meters as well. I know some one that works for a medical marijuana processing equipment manufacturer, I’ve been to trade shows. One company had these meters that were the size of a beer can with a globe on top, they were “only” 399. I can’t find or remember the brand.

14

Yes, im not a water head and I know 1 lux = 1 lumen sq/m and it is essentially the lumen intensity for 1sq/m.

The term “lux sensor” is used for a whole variety of sensors and not just the cheap LDR, photodiode, and photocell you wrongly assumed are the only ones im familiar with.

Again… What do you consider “a real lux sensor”?

15

I think this is the company. What do you not understand by true? That the reading gives you the exact amount of light as defined by scientific standards.

16

Am I wrong with this theory? We need 1 ro 10 volts. And all lamps i know provide gnd, 10v out for the potentiometer/or to provide my circuit 10v. If i use for example an esp32 with 12 volt to 3.3 regulator onboard, it needs only a small voltage levelshifter, what on the end is a simple mosfet transistor and a resistor connected to 10v. The PWM signal is only on or off. No need for dac converters or fancy stuff. Maximum a lowpassfilter with a resitor and capacitor