ESP8266 Community Forum

- Sat Jul 01, 2017 4:55 pm #67809 Also invest in a basic digital multimeter. They can be had for a few pounds / dollars and are an essential aid in understanding and testing.

You don't want to wait a week and waste batteries trying to figure out where the current is going,

- Mon Jul 03, 2017 6:35 am #67852

Also invest in a basic digital multimeter. They can be had for a few pounds / dollars and are an essential aid in understanding and testing.

You don't want to wait a week and waste batteries trying to figure out where the current is going,

Stop using AAA batteries. Use AA at the least.

As far as the code. Turn a pin high on power up. This pin is for the sensor power. Get the reading. Then turn the pin low. Send your information, then power down.

WiFi is not a low power way of communicating. Its cheap and its easy.

You are right but I'm for the device I'm working on I'm restricted by design. I had to keep the circuit very small. I'm gonna look for other alternatives. If you have other long-life battery suggestions I would love to hear them.

Hi, is the DH11 +ve connected to 3.3V or one of the GPIOs? If its connected to 3.3V it wil be powered all the time and use something like 200mAH in a week. If you power it from one of the GPIOs it will only draw 2mA when measuring. Whilst that doesn't account for all the cells discharge it will help.

I'm gonna try this looks like useful idea. Do you think are ESP's GPIO pins strong enough to keep dht alive?

- Sat Jul 08, 2017 7:52 pm #68092

Hi I made a temperature logger, with Esp12 and DHT11.

I strongly recommend you use a different temperature sensor. The DHT11 are rubbish. The DHT22/AM2302 aren't much better. Even if they start off reading correctly they drift or fail quickly. If you only need temperature then the BMP280 are very and cheap. If you need humidity then the SHT30 or BME280 are both very good.

- Sun Jul 09, 2017 5:56 am #68098 For pure temperature measurement the DS18B20 take a lot of beating.; very small, low standby current, accurate, cheap and only need 1 GPIO pin to collect data from one or more sensors.