ESP8266 Community Forum

- Thu Apr 26, 2018 3:51 am #75603 Hi!

I am building a sensor to my sewage tank. The plan is to have a float switch (like on a pump) as a high level sensor and a NodeMCU board to send this information on e-mail.

Can I use the float switch directly to power on the board instead of leaving the board into a Deep Sleep to save battery life? Plan is to power it with 3 AA batteries and have the float switch in between the + line of the battery.

It will signal 1 time per month. After sending the e-mail, something will cut off the power again like this: https://www.aliexpress.com/item/DC-3-12 ... 0.0.XM3Qpn . So when the float switch turns on the NodeMCU it connects to wifi and sends 1 email. In approx 1 minute the Delay circuit will cut the power again, so only this circuit will be under power as long as the float switch keeps the power on (1-3 days). After the truck comes and the float switch will go down and cut the power, the battery is not drained anymore. How much could this circuit power consumption be?

If i could solve the battery issue, it would be more fancy to use a waterproof ultrasonic sensor instead, but would be nice to have a 12 month lifetime for the batteries, but I can not see this without cutting the power, as Deep Sleep still drains the battery on NodeMCU

- Sat Apr 28, 2018 5:25 am #75649 Is using a NodeMCU board a firm requirement? The NodeMCU isn't so power efficient due to its voltage regulator and UART chip always consuming some current, so other ESP8266 boards can be easier to get long runtimes off batteries.

- Sat Apr 28, 2018 6:48 am #75651 I bet an ESP-01 with just two AAA batteries will do the job.

I have a similar project and it even has a WS2811 neopixel attached. No power booster etc.
Everything just running from 2 AAA batteries.

I push a switch, the ESP gets powered and does its thing. I release the switch and the power is cut.

Forget about the NodeMCU for these simple projects where just 1 IO pin is needed.

Luc

http://lucstechblog.blogspot.nl

- Sat Apr 28, 2018 7:38 am #75652

I bet an ESP-01 with just two AAA batteries will do the job.

I have a similar project and it even has a WS2811 neopixel attached. No power booster etc.
Everything just running from 2 AAA batteries.

I push a switch, the ESP gets powered and does its thing. I release the switch and the power is cut.

Forget about the NodeMCU for these simple projects where just 1 IO pin is needed.

Luc

Agreed, same here. It needs to be emphasised to people that the NodeMcu et al is a 'development board' which means used to develop your project, as it is convenient, but it is not necessarily the right hardware for the final 'deployed' item, especially when running on battery.