ESP8266 Community Forum

- Sun Aug 02, 2015 4:10 am #24811

When you play with these things its expected that you will do the research yourself not keep asking others to do it for you . That's the fun , research it , think it through a,build it and then you get the satisfaction of doing it yourself when it works.

The reference you put up says
DC Current per I/O Pin 40 mA
DC Current for 3.3V Pin 50 mA

The 5 V will only get what the computer puts out for that particular board . Probably 250 to 500 mA , I don't remember. So you can try it and see but if its erratic suspect the power supply first

Yu need to research the RX/TX lines .. I thought I saw they were not crossed but that was for programming another arduino chip. You might have to cross them for what you want.

Thanks - I'm not too concerned about the Rx/Tx as I can, as you said, play around with it. The thing I'm trying to avoid is releasing the magic smoke The majority of the parts for my project (Including the ESP8266) come in on Monday, so I'm just doing pre-planning, which is why I'm probably way overthinking it

As for the 5v - I'm not so much concerned with its short term power availability when hooked to the computer, but the overall project is going to be standalone, and while the Arduino does have the AC plug point, the USB based power solutions tend to be more compact, which works best for my purposes. I can reliably send 1A through the 5v via that method which means that power shouldn't be an issue.

Thanks again for your help!

- Sun Aug 02, 2015 4:19 am #24812 Oh OK I see what you are doing now . Pre stage nerves maybe . All good

I can reliably send 1A through the 5v via that method which means that power shouldn't be an issue.

I understand that with a plug in wall wart supply might give 1 Amp but with USB the configuration of the device plugged in is set by the computer according to the devices needs as I understand it so how will you alter that? Do you have a method in mind. I have not looked it up but what does the UNO get when plugged in?

USB Overcurrent Protection

The Arduino Uno has a resettable polyfuse that protects your computer's USB ports from shorts and overcurrent. Although most computers provide their own internal protection, the fuse provides an extra layer of protection. If more than 500 mA is applied to the USB port, the fuse will automatically break the connection until the short or overload is removed.

I found this on the product page too so I guess it must set up with a 500mA or more draw capability or it would not need this protection

Get you modules here:

https://www.banggood.com/custlink/KvGGhGF4wG

- Sun Aug 02, 2015 1:40 pm #24835

Oh OK I see what you are doing now . Pre stage nerves maybe . All good

I can reliably send 1A through the 5v via that method which means that power shouldn't be an issue.

I understand that with a plug in wall wart supply might give 1 Amp but with USB the configuration of the device plugged in is set by the computer according to the devices needs as I understand it so how will you alter that? Do you have a method in mind. I have not looked it up but what does the UNO get when plugged in?

USB Overcurrent Protection

The Arduino Uno has a resettable polyfuse that protects your computer's USB ports from shorts and overcurrent. Although most computers provide their own internal protection, the fuse provides an extra layer of protection. If more than 500 mA is applied to the USB port, the fuse will automatically break the connection until the short or overload is removed.

I found this on the product page too so I guess it must set up with a 500mA or more draw capability or it would not need this protection

I was basing my assumption on power availability on this post - Assuming the Arduino itself draws 100mA or less from my 1A supply, I'm left with ~900mA maximum draw. I'll be supplying power at the 5v level through USB, so no big worry on heat on the regulator, and I'll be way below the power draw with the ESP-01 drawing ~150mA.