I've to use ESP8266 WiFi module in my university graduation project.It's working rates are 3.3 V and ~ 200 mA (max) as I understand it's datasheet. I'm using Arduino Uno card which gives me 5 V output. I searched on net and most of the forums on websites suggest to use 3.3 V voltage regulator.However, I couldn't find 3.3 V regulator at a place where I live in.I can order it but it will probably take a week to delivery time. Do you think I can make a simple voltage divider circuit with only resistors that gives me 3.3 as an output?What if I use 3 x 1.2V 1300mAh Duracell Rechargable Battery for separate source for only WiFi module?
As I know, the current rating of a supply is what it can deliver, not what it will always force thru the load somehow. In that sense, unlike with voltage, the current rating of a power supply must be at least what the device wants but there is no harm in it being higher.
No you cannot use resistors to provide a known voltage when there's a varying load on them - and the ESP8266 power draw varies wildly - from a couple mA to hundreds - depending on what it's doing
You've got a shipping-time delay in your future no matter what.
If you're in the US, and order from digikey, if you place it in time for them to ship via USPS first class today (USPS first class is amazing - not only cheap, but faster than a lot of more expensive options), you'll likely have it teusday, maybe wednesday next week. Get some appropriate caps for input and output of the regulator as well (check datasheet for recommended values and types of caps - almost every regulator will recommend values for input and output caps, as well as whether they should be ceramic or tant - I would recommend getting ones that let you use ceramic caps, since ceramics are cheaper and don't explode if you connect them backwards like tants).
3.3v and 5v regulators (as well as common values of caps and resistors) are the sort of part you want to keep on hand, so you don't end up with projects on hold waiting for them.
I faced the same problem a few weeks back. The resistor method wont work at all, as stated by others.
I personally used the 5V supply from a usb port of my pc and used a "lm2596 dc dc buck converter"(like this one or maybe this ). You can use any power supply like batteries or adapters of 5V, 9V, 12V,etc and bring it down to a constant 3.3V by varying the trimpot on that. Really handy.
Hi,
If you need 3.3V urgently, see if you can get a LM317 linear variable regulator.
The data sheet will tell you how to set it up to any voltage you need.
The catch is you will need at least 7V input for it to regulate reliably.
However, I want to work on my project until I got one of them in a week, (if I'm lucky). I mean, I want to start programing and get communicate between home network and ESP. So ;
If I make connections like you see in picture down, will it work? may I damage ESP or HC-SR04 ?
As I know;
HC-SR04 (VCC) -> 5 V
ESP8266 (VCC) -> 3.6 V
ESP8266 (RX/TX) -> has 5 V tolerance ?
I have never take into account the currents that will each pin draw.So, is everything OK?
I'm not good at this stuff, so I'll appreciate it if you guys give me advice.
I posted similar message to Arduino Forum > Using Arduino > Networking, Protocols, and Devices
Also in the wiring diagram wire the -ve of battery should be connected where the yellow lines meet on the breadboard, they should all have a common ground.
The esp8266 datasheet sheet says 3.6 is the MAX voltage, so i suggest you drain you batteries a little and measure it with a multimeter so its closer to 3.3V and not higher than 3.5.
Use it directly without measurement at your own risk.
