Waterius

Goal

Transfer water meter data to mobile phone using home Wi-Fi. Use AA batteries for power.

Waterius can sends:

• current values everyday
• delta values (per day)
• voltage
• e-mail by Blynk (title and message template)
• data to your TCP server

Values saved in ATtiny EEPROM cycle buffer (~2 millions cycles). "Software ESD protection".

How It Works

Two chips: ATtiny85 in deep sleep mode. It counts impulses and wakes up ESP-01 to transfer data to Blynk every day. Chips talks by i2c line.

Power: 3*AA batteries (or 2*AA lithium batteries without voltage regulator)

Current: 15-24 uA in deep sleep, 75 mA when transmitting for ~5 sec

Lifetime: estimated 4 year battery life

Limits: 2 impulses per second (increased by constant in code)

Inputs: 2 water meters

Step One: Solder Scheme

I use Wire-To-Board terminal block 2.54mm step.

Step Two: Firmware

1. Upload firmware to ATtiny85 by ISP programmer or Arduino board as ISP programmer.

This is a view of the female connector 4x2 pins for ESP-01:

• | GND - SCK - MOSI - nc |
• | nc - MISO - nc - Vcc |
• + ATtiny85 reset pin
• nc - not connect
• Vcc - 3.3-5 V

2. Upload firmware to ESP-01 by USB-TTL converter or Arduino UNO (use level converter or voltage divider 1k + 2k resistors on ESP RX line).

If you use Arduino IDE, you need to add and patch libraries.

Additional libraries:

• WifiManager by tzapu (0.12.0)
• Blynk by Volodymyr Shymanskyy (0.5.2)

(!) Patch WifiManager library:

• Open WiFiManager.h file
• Move WiFiManagerParameter class 'init' function from private to public

Step Three: Package

I use 4 AA batteries plastic box as Waterius case. The Waterius board has AA battery dimensions. Drill 2 holes on the side for LED and the button.

Prepare ESP: cut 3mm of pins and remove plastic pins shield. Now it can be placed inside the box.

The current without ESP should be 4-10 uA, with ESP - 15-24 uA (depends of ESP...).

Setup

• Clone Blynk project by QR code
• Copy ESP8266 device KEY to phone clipboard
• Connect device to water meters' dry contacts

Push button to turn on Active Point (192.168.4.1)

• Connect to Active Point and fill: your home Wi-Fi title, password, Blynk device key, current water meter values
• After 3 minutes Waterius will send you a values to check connection

Now you will receive a values every day. Enjoy!

Blynk config:

• V0 - water meter #1
• V1 - water meter #2
• V2 - voltage (after power regulator if present)
• V3 - value #1 delta
• V4 - value #2 delta

Please ask any questions on GitHub page!

To Do:

• STM8L scheme
• Over the air update
• Water sensor alarm
• Power off ESP-01 by MOSFET