More work on the CaptiveIntraweb - ESP-01 NodeMCU

With all basic programming issues out of the way, I built a first prototype of a somewhat oversized Wifi-throwie. Schematics will be published in one of the next posts.

There is a 1N4001 diode hidden in the red heat-shrink tubing to get rid of about 0,6V. It might not be the most energy efficient way to drop a few thenths of volts, but it sure is cheap.
For the power consumption I measured 70mA. That is A LOT!
With an estimated realistic capacity of around 1000mAh, my Ultrafire battery will only give me a 14h run time.
Not really spectacular.
This also makes it rather inefficient for a tiny WiFi-throwie. A CR2032 has around a capacity of around 200mAh, giving us only 3hrs of fun.
ESP8266 sleep modes (according to the WIKI) do not work in SoftAP mode. So the only thing that helps is a bigger battery.

Battery options:

• CR2032 (3V / 200mAh) < 3h
• 14500 Lithium cell (3,7V, 800 mAh) > 10h
• 18650 Lithium call (3.7V, 2000 mAh) > 28h
• Energizer L92 (1,5V, 3000 mAh) > 40h

I have some unused, low quality 18650s, matching battery holders and a suitable enclosure, so I'll stick with them,

Cost:

• 18650 battery (well, nothing really but let's say:) = 2€
• ESP-01 = 3,30€
• Battery holder = 1€ (less)
• Dupont cables = 1€ (less)
• Enclosure = 1,30€
• 1N diode = 0,10€ (less)
• Rare earth magnet = 1€

So I get away with less than 10€ (also less than 10$ US) - Cheap enough to put at risk in public places. That is why I shy away from good quality 18650s.

The code on github is a bad mess of English and German fragments. The next step is to clean up the translations.