Hi, I am new to IoT projects. I have some doubts in supplying power to the ESP8266-01 wifi module. I searched and found that the 3.3V from the Arduino Uno is not sufficient to power the module as it only supplies up to 50mA. So could I use a LM1117 regulator to step down the 5V from the Arduino pin to power the ESP8266? As I do not want to have an external power supply to power it. I will use a 12V 2A AC-DC adapter to plug in the barrel jack to operate the Arduino. Another question is if I supply power through barrel jack and have all the components connected to the 5V pin of the Arduino, is it not sufficient to power them if the total current consumption of the components is higher than 50mA?
It would be a lot lot better for your electronics to supply 7.5 to 9 volts to the Uno, via the wall wart. By supplying 12V and that the Uno is using only 5V, the rest of the available 'power' is thrown away as heat.
Do not power the ESP8266 from the Arduino 5V pin. Instead you can tap off of the barrel connector, solder and wires, the incoming 7.5V to 9V, send it to a 3.3V regulator such as a MCP-1700. Not super for the 3.3V regulator but from the situation described, workable.
Thank you for your reply. What do you mean by tap off? My project involves other components like load cell, 2 LED, buzzer and 16x2 LCD. If possible I would like to have only one power supply to operate all of these components.
'tap off' you know like how there is a fire hydrant and the fire hydrant has several taps for hoses of various sizes. Like a 4 inch, 6 inch 8 inch hose. Each hose tap would be like a different voltage regulator using one source. got it? No? Don't know how better to explain it to you.
Got it. Thank you for your time.
Have you considered Buck or SEPIC Modules, currently they are very cheap on several of the China suppliers. They are generally in the high 80% to 96% efficiency range. With a linear regulator you will at best get 50%. The difference in efficiency is the amount of heat generated when burning up excess voltage. You can compute this dissipation from the output power and the efficiency. The output will be 5V * 1.5A = 7.5W. If the switcher is 80% efficient, for example, then the total input power will be 7.5W / 0.8 = 9.4W. The difference between the output power and the input power is the heating power, which in this case is 1.9W. That's way better than what a linear regulator would do. The nice part about them they have 2 input connections and 2 output connects with ground generally being connected on both the input and output. Not all have the grounds connected so be careful.
Thank you for your suggestion. I bought a LM2596 step down converter to step down 12V to 5V. Then I will use resistors to convert 5V to 3.3V.
I would suggest another converter, or using the one you have as the 3.3V supply. Initially the resistors sound like a good solution until you look at the load, it will be changing and if you go to high in voltage it will fry the load. If it drops to much the load goes bonkers. The UNO will work just fine with a 12VDC input on the barrel connector, using the same source as the DC-DC converter.
I used the converter to step down 12V to 3.3V and supply to ESP8266, but it is not working at all. The blue LED on the ESP8266 is lighting up the moment when I turned on the switch. The same goes for when I used the 3.3V from Arduino, it does light up at the time I switched on the power but immediately goes off. Can someone help me?
I gave up with trying to run ESP through an UNO. bought a UART USB 3.3V Serial interface from the 'bay, built a small test board with a plug for the ESP, and can via the switches turn the power on/off, and pull down the terminal to flash the device. Once uploaded I can then test and see if the outputs are working on the LEDs, and there is enough power to run it from the USB. Also gets used for ESP32, 13, etc., and I can update the firmware too (Espressif do their own tool). Much easier.