What is it?

ULP Weather Logger is a WiFi IoT device that has 4 sensors with 6 measurements. Works with two AA batteries. Thanks to its compact design, you can place it anywhere you want.

Manual update by pressing one shot button

Features

• Ultra compact design
• Internet connection via WiFi (ESP8266 - ESP-03)
• 4 sensors, 6 measurements
• Temprature & humidity (HDC1080)
• Barometric pressure (LPS25HB)
• Visible & infrared light (TSL2561)
• Ultraviolet light (VEML6070)
• Battery voltage monitor (MCP3021)
• Thanks to the system timer, it has ~50nA current consumption at shutdown state

This device wakes up and updates at certain intervals. By default, it's every 20 minutes. This can be customizable by changing R3 and R4 resistors. See "Resistors selection" section.

Getting started

Once you have received, it comes with default sensor test sketch. You need to customize and flash your own sketch once. Arduino and Blynk example codes provided on Github repository.

You need to customize these lines in WeatherLoggerBlynkVirtualWrite.ino with Arduino IDE:

What do you need for programming?

• Two AA batteries
• USB to UART Bridge
• Arduino IDE

How to program?

1. Solder battery holders (Be careful to solder right polarities)
2. Insert the fresh batteries
3. PWR Led will lights up and it will shutdown after ~2 seconds. This is testing sketch. When you press "ONE SHOT" button, it wakes up again.
4. Connect USB to UART adapter. GND to GND, TX to RX, RX to TX, VCC is not necessary. (Make sure your UART adapter logic levels. It must be 3.3v)
5. Press FLASH button, Press and release ONE SHOT button. It's in bootload mode now.
6. Upload your sketch. You are ready to go.

Enter bootload mode

Exit bootload mode

Press reset button.

If you uncommented DEBUG flag on your sketch, you can monitor serial port to see what's happening when you press ONE SHOT button.

What you get?

• ULP Weather Logger v1.1
• 2x AA Battery holder (optional)
• 1x4 Male header (optional)

Battery selection

I recommend to use two AA alkaline, NiMH or NiCD batteries.

Battery life

It depends on a few things. e.g., update frequency, distance between WiFi router, internet speed etc. In normal conditions, one update takes 1-1.5 seconds. I don't have precise testing instrument, but I have reached 5 months battery life during my real life tests with two 2400mAh NiMH batteries.

(*) Tested with 2*2400mAh Ni-MH batteries.

Battery life extending tips

• Place ULP Weather Logger to your WiFi router as near as possible.
• Choose less frequently update interval.
• Include your WiFi router's Mac address, channel information in your sketch to connect faster.
• Select a server with a lower ping time. e.g. choose closest Blynk server.
• Cut JP2 to disable power indicator led.

Resistors selection

If you want to change update interval, (by default, it's 20 minutes) replacing R3 and R4 is necessary. Please refer to the table* below.

(*) from datasheet of TPL5111

Power consumption

In sleep

Active state (During One Shot)

Measured from JP1.

@3v battery:

@2.5v battery:

@2v battery:

Open source

Hardware and software are 100% open source. Design files, schematics and codes are on Github repository.

Known issues

There are no issues currently reported.

Shipping

I'll ship all the boards with tracking number. Let me know if there is no shipping option to your country. I'll have a look.