Remote control 4x 50W LEDs with ESP8266, HC05 and Smart Phone

[gophert]

Which resistors are fitting for the mosfet gate resistor?

10 ohms if you are going to do any PWM dimming, but 100 to 470 are fine if just turning on/off once every few seconds to hours.

I still have no idea what the resistors after the LEDs are for and how much resistance they got to have.

Post the LED or light strip you plan to use.

Should i pick another board instead of the ESP8266 since i wont use WiFi at all? Would e.g. the digispark pro?

It depends on what you are trying to do with the light strips (dimming, signaling, etc. the esp8266 will definitely work - it is very fast chip - 80MHz. Remember, the I/o pins only output 3.3v so you need mosfets that turn on completely with only a 3.3v signal.

In summary, let us know what you are doing so we can answer.

Should i use a voltage divider to get the desired 3.3V at the BT-Module input?

No, you should use a 3.3v regulator. If the current draw is under 100mA, you can use the regulator that sends 3.3v out to the "3V" pin on the ESP8266 (if it has one).

7805 Voltage Regulator is specified with a max Input Voltage of 25V, will that be a problem? Do I need additional parts like capacitors for this voltage regulator?

Yes, install as shown in datasheet with caps.
Why do you use 28v?

 

[pezigan]

Will I have to use PWM if i'm going to let the LEDs blink? What i wanna do is blink the LEDs in approx. 1 sec intervals.
Furthermore i want to be able to turn on/off the LEDs pairwise (1&2 / 3&4). I am going to control all this from a mobile app.

These are the LEDs im using.

I'm using 28V because the spotlight is already provided with this power supply (battery) and I thought of it as a good solution.

 

[gophert]

Will I have to use PWM if i'm going to let the LEDs blink? What i wanna do is blink the LEDs in approx. 1 sec intervals.

No, just switch on/off is fine with gpio - no PWM needed.

Furthermore i want to be able to turn on/off the LEDs pairwise (1&2 / 3&4). I am going to control all this from a mobile app.

Ok, sounds good if you can write that code.

These are the LEDs im using.

I'm using 28V because the spotlight is already provided with this power supply (battery) and I thought of it as a good solution.

Make sure to connect using the 24v at 2Amps unless that is self-regulating in the unit and you just need to supply power.

If so, your resistor calculation is: (28v - 24v) / 2 amps = 2 ohms. It needs to be a chunky resistor because you are dropping 4v at 2 amps, so 8 watts. You should buy a 15 to 25W resistor for each lamp (these are typically aluminum with mounting lugs. Don't mount the resistor to the aluminum housing. Your lamp will already be trying to dump excess heat it makes by itself. It likely can not handle an extra 8 watts of heat input or your LEDs will overheat.

Get a separate heat sink and enclosure for your controller's box. If you plan to put all four in the same box, you'll have some trouble with the 32 watts of heat.

 

[summitville]

Use a 5 Volt Switching regulator, with a 36 Volt Input.
something like this ...
5Volt-Regulator

Or a 3.3 Volt Switching Regulator?
3.3Volt-Regulator

 

[pezigan]

Make sure to connect using the 24v at 2Amps unless that is self-regulating in the unit and you just need to supply power.

If so, your resistor calculation is: (28v - 24v) / 2 amps = 2 ohms. It needs to be a chunky resistor because you are dropping 4v at 2 amps, so 8 watts. You should buy a 15 to 25W resistor for each lamp (these are typically aluminum with mounting lugs. Don't mount the resistor to the aluminum housing. Your lamp will already be trying to dump excess heat it makes by itself. It likely can not handle an extra 8 watts of heat input or your LEDs will overheat.

Get a separate heat sink and enclosure for your controller's box. If you plan to put all four in the same box, you'll have some trouble with the 32 watts of heat.

The spotlight is already a fully functional with the switch. So the LEDs are already lit up when i switch to I (LED 3 & 4) or II (ALL LEDS). All i gotta do is to add the ESP and the control to the spotlight.

Thanks for the recommendations summitville. Is this Regulator fitting too? Or do you think I'll have to add a heatsink in addition to the capacitors?

 

[Dr_Doggy]

may I suggest a buck converter to replace the regulator ... that will be your major power saver

I dislike bluetooth , it takes a bit to connect , can only have one connection and not fun to program since its just a serial socket

ESP you can use with the arduino IDE , it can host wifi when not on a network , ,, its simple enough that you can use as serial socket to get started but then can host its own webpages if you want to take the time for programming

 

[gophert]

may I suggest a buck converter to replace the regulator ... that will be your major power saver

I dislike bluetooth , it takes a bit to connect , can only have one connection and not fun to program since its just a serial socket

ESP you can use with a arduino , it can host wifi when not on a network , ,, its simple enough that you can use as serial socket to get started but then can host its own webpages if you want to take the time for programming

Umm, did you mean "with an arduino" or "with the arduino IDE"? No need for an arduino, it can be programmed with the Arduino IDE.

 

[Dr_Doggy]

corrected!@

 

[gophert]

corrected!@

I just needed to clarify because there were a lot of projects early in the release of the ESPs where simple AT programs were loaded by a companion Arduino (since they were easier to program). Now, as The ESP manufacturer finally released documentation in English and the Arduino IDE was made ESP compatible, life is easy and the projects can be amazing.

 

[Dr_Doggy]

some esp boards are missing the programming bus, but the one in the post does have the usb

 

[Nigel Goodwin]

some esp boards are missing the programming bus, but the one in the post does have the usb

They ALL have programming capability (no idea what you mean by 'bus'?), some have a USB/SERIAL chip on board, others need an external one to program them (or a computer with an actual serial port, that is 3.3V compatible).

For the tiny ESP01 boards (with the horrible dual pins) you can buy a cheap programming adaptor that has a suitable USD/Serial chip on board, and a switch for selecting programming or run.

 

[Dr_Doggy]

somehow i was able to purchase the one that doesnt ... and now i have embedded esp trauma

https://www.olimex.com/Products/IoT/ESP8266/MOD-WIFI-ESP8266/open-source-hardware

 

[Nigel Goodwin]

somehow i was able to purchase the one that doesnt ... and now i have embedded esp trauma

https://www.olimex.com/Products/IoT/ESP8266/MOD-WIFI-ESP8266/open-source-hardware

Except that isn't really an ESP8266 'board', it's just a specific add-on module for another board. And even then, it's still reprogrammable by soldering the links on the back.

 

[gophert]

somehow i was able to purchase the one that doesnt ... and now i have embedded esp trauma

https://www.olimex.com/Products/IoT/ESP8266/MOD-WIFI-ESP8266/open-source-hardware

That was one of those stupid attempts to use the inexpensive and powerful ESP as an "add-on" for a crap microcontroller. Who would use an add-on that is a more powerful (32-bit 80MHz) than the base microcontroller? Why buy an add-on board when they claim "The rest of the pins of the chip are NOT routed for easier access". Please stop commenting on esp8266 or esp32 - they are not helpful.

 

[pezigan]

I just noticed that the way i want to build the whole thing, there is no smooth way of getting the full functionality from both the switch and the mobile app at the same time. So lets say I let the LEDs blink and then turn off the app. What happens now? Maybe after Bluetooth connection closes the esp should let current flow through the mosfets just to be sure.

\e: Some additional feature: is there a simple way to get the remaining battery life from the battery in the arduino? Just take the full capacity of the battery (5 Ah) and subtract the usage? I mean I have a full overwiev over the usage since the esp controls the leds and i know how much current the controller itself draws. Only thing I have to assume is that the battery is fully charged when turning the device on. Any other recommendations?

I've also read something about measuring the Voltage using the ESP PINs but I'll have to add a voltage divider to handle the 28V.

 

[Pommie]

there is no smooth way of getting the full functionality from both the switch and the mobile app at the same time.

Maybe if you told us what the functionality is we may be able to help.

Mike.