Step 1: Backplane PCB proofing and welding
Step 2: Register an MQTT topic
Step 3: Write the program of the Future board
Step 4: Check the real-time data through WeChat mini program
Result

Team Kittenbot:

Anny Xu

•

Christina Zhang

•

Riven

Published October 25, 2021 © MIT

IoT Smart Plant Assistant made with ESP32 Future Board

Make a plant assistant with the ESP32 Future board to remind you to water the plant when the soil is too dry

BeginnerFull instructions provided3 hours918

Things used in this project

Hardware components

KittenBot Future Board

KittenBot 400mAh Rechargable Lithium Battery Pack for Meowbit

Software apps and online services

KittenBot Kittenblock

Story

We have so many plants in the office because they can purify the air and bring us a pleasant mood. And there are three fundamental elements to grow a plant: light, carbon dioxide, and water. We'd love to take care of them carefully based on these three basic elements, so we took water as the main aspect this time to make this project.

In addition to all the things above, we also need gadgets below:

1 × Soil moisture sensor
1 × Battery backplane PCB (need to make a proof, will be explained below)
7 × M3*12mm brass pillar
14 × M3 Screw
1 × PH2.0 3pin wire
1 × PH2.0 3pin terminal head

This project includes the following features:

Detect the real-time humidity value of the soil
Upload the detected humidity value to the Kittenbot IoT platform
Get the IoT platform data through the WeChat mini program

Step 1: Backplane PCB proofing and welding

1. Scan the QRcode below to download the PCB file that we prepare for you, which can be used to make a proof directly.

After we receive it, we can wield our board.

1. We only need to weld a PH2.0 terminal head to plug the soil module.

2. Use screws to fix the brass pillars, paste double-sided tape on the wireframe of the circuit board to fix the lithium battery. After connecting the soil module, install the Future board on the PCB circuit through the brass pillars, then you have assembled the device basically. (The P0 of the Future board should be connected to the soil module)

Step 2: Register an MQTT topic

1. Enter the Kittenbot IoT platform iot.kittenbot.cn (The platform is in Chinese currently, but don't worry, you can still finish this project easily with the step-by-step tutorial)

"add a topic"

2. Create a new topic name, which should be unique, distinguishable, and easy to remember, such as /hum123

“Topic Name" "Topic Subscription User Name" "Topic Subscription Password"

3. After creating the topic, the topic /Hum will be shown on the left side. You can view the data under this topic by simply clicking it.

Step 3: Write the program of the Future board

1. Open Kittenblock, connect to the Future board, click the hardware to connect it to the computer

2. Write the program according to the figure below, change the parameter of the name and password of your router, change your topic name.

3. Switch to the offline code download mode, download the code to the firmware.

4. Debug data, put the sensor in the air as shown in the figure

The reading is 3406
When completely immersed in water, the reading is 1525
According to the requirements of different plants on the soil humidity, we should keep testing and find a suitable soil humidity value. The actual measured value of the soil I have on hand is around 2104, which is suitable for growing the plant.

Step 4: Check the real-time data through WeChat mini program

1. Open the search bar and click the mini-program

2. Type in "microbit", click "search" to enter the mini program.

3. Open the IoT panel, click "connect directly"

"Server" "User Name" "Password" "Connect"

4. Type in your topic name, click "subscribe", then you can receive the messages of your topic.

"Disconnect" "Topic" "Topic Content"

5. According to the program you wrote in the third step, you can receive the soil data every 3 seconds.

"Disconnect" "Topic" "Topic Content"

Result

Now, let's give it a try!

plant assistant.py

#/bin/python
from future import *

from time import sleep

import mqttsimple

P0 = MeowPin('P0', 'ANALOG')

x = 0

buzzer.melody(CORRECT)
screen.sync = 0
sleep(3)
if not wifi.sta.isconnected():
  wifi.connect(str("Kittenbot"), "xxxx")
sleep(1)
mqtt = mqttsimple.MQTTClient("iot.kittenbot.cn", "hum",port=1883)
mqtt.connect()
while True:
  x = P0.getAnalog(12)
  mqtt.publish("/Hum", str(x))
  screen.fill((0, 0, 0))
  screen.text(x,10,10,3,(0, 119, 255))
  screen.refresh()
  sleep(3)