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I'm new to electronics. I've built this:enter image description here

It's an ESP-01 Wifi chip and a DHT22 temperature/humidity sensor. Now I'd like to power it with batteries instead of an Arduino. The ESP-01 requires 215 mA, the DHT22 requires max 1.5 mA.

This post shows powering such a set-up with a 3.7v battery regulated with a HT7333 voltage regulator.

However, as AA batteries are more available in my neighbourhood, I thought maybe I should use a "step-up"/boost chip to boost 2 AAs to 3.3 volts.

Is this a good idea? And which particular chip would be easyish to use on a breadboard and hopefully eventually solder?

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  • \$\begingroup\$ You can use 3*AA with a regulator but why don't you use the 3.3v output of the arduino? \$\endgroup\$ – RedNez Dec 27 '18 at 18:32
  • \$\begingroup\$ Pretty obviously because the Arduino wouldn't be in the system, and even if it were using linear regulators to get from the Arduino's minimum input voltage of > 7 volts down to the 3v3 operating voltage would be terribly wasteful. \$\endgroup\$ – Chris Stratton Dec 27 '18 at 18:33
  • \$\begingroup\$ Even with a switching regulator implementing ideal power conversion, this would still be a project that would run down the battery quite quickly. You first need to make the ESP sleep in an ultra low power mode the overwhelming majority of the time. That's probably going to mean waking up very infrequently, spending some time joining a wifi network, transmitting a reading, then going back to sleep for tens of minutes. Wifi is not very suited to such a usage; you might try the ESP's non-wifi raw modes using another ESP as the receiver. \$\endgroup\$ – Chris Stratton Dec 27 '18 at 18:35
  • \$\begingroup\$ i he's going to remove the arduino then ok but if he's keeping the arduino he can power it with a power bank or something \$\endgroup\$ – RedNez Dec 27 '18 at 18:35
  • \$\begingroup\$ Is wired power unavailable minisaurus? \$\endgroup\$ – K H Dec 28 '18 at 2:43
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I am in the same boat. At 69 I decided a few months ago I wanted to learn electronics and boy with all my medication slowing my brain, learning is hard. I was an electrician most of my working life but always wanted to get more involved. I too chose the Arduino way to start off and some things worked easily. For one of my projects, I am attempting to build a wireless weather station with LCD at the indoor end myself using more or less the same as you are.

As for powering a UNO away from my computer I tend to use a 9v PP3 type battery and for that from Ebay, I purchased 5 leads that clip to my battery then into the UNO. I also purchased 5 more with soldered + & - ends and I soldered the ends to an AMS1117, 800 ma, 3.3v regulator, to ensure I had stable 3.3v. You could use an Arduino 3.3v Pro mini for your project as well. I don't know much yet, but I do know that works for me.

Hope it helps.

Petyoung

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  • \$\begingroup\$ This post has two serious problems. First it is too long and chatty with the technical information hidden. Next the actual technical suggestion is horrible. Using a linear regulator to go from 9v to 3.3 volts is overwhelmingly wasteful, well over half of the battery will simple generate heat. And that is a point which was already made in comments above before you posted this. \$\endgroup\$ – Chris Stratton Jan 4 at 15:33
  • \$\begingroup\$ I like to chat :) and personally I like petyoung's introduction and the pace of his prose. He/she is a new contributor so we should help him/her in a friendly way? \$\endgroup\$ – minisaurus Jan 5 at 14:35

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