REV 1.0
Moisture Sensor with an ESP8266 12F (Wifi/Wlan) This project is still work in progress!
This sensor is intended to measure the soil moisture of plants and to send them by WIFI to a server for data evaluation. An ESP8266 module is used for the sender to send data over the air. A capacitive measuring method is used as a sensor to get moisture values. The basic framework of the sensor is based on the [Gies-O-Mat von Fred Ram]1
A 18650 battery is to be used as power source, as this can have high capacities. A long life per battery can be guaranteed. It is assumed that the sensor can operate for up to 3 months at half-hour measurement - This must still be proven!
Layout was made with Eagle 7.72
First try to model a case for the board in 3d
GPIO5 is now used to control Vin in smitt trigger to use less power when sensor is not measuring.
Qty
Value
Device
Package
Parts
Description
Price per pc
Order-Link
2
PINHD-1X2
1X02
1RX-2TX
3,3V-2GND
PIN HEADER
0,28 € (0,71 € / 10pc)
https://www.reichelt.de/Buchsenleisten/MPE-115-1-010/3/index.html?ACTION=3&LA=2&ARTICLE=119955&GROUPID=7435&artnr=MPE+115-1-010&SEARCH=%252A
1
100Ω
R-EU_R0603
R0603
R3
RESISTOR, European symbol
0,02 €
https://www.reichelt.de/SMD-0603-von-0-bis-910-Ohm/RND-0603-1-100/3/index.html?ACTION=3&LA=5&ARTICLE=183013&GROUPID=7967&artnr=RND+0603+1+100
1
1000µF
CP-SV-E/F
SV-E/F
C1
Big POLARIZED CAP
0,32 €
https://www.reichelt.de/Elkos-SMD-Low-ESR-105-C/VF-1000-6-3-P-F/3/index.html?ACTION=3&LA=5&ARTICLE=109181&GROUPID=4001&artnr=VF+1000%2F6%2C3+P-F
2
10µF
C1206
1206
C2, C4
Small SMD Cap
0,07 €
https://www.reichelt.de/Vielschicht-SMD-G1206/X7R-G1206-10-16/3/index.html?ACTION=3&LA=5&ARTICLE=89740&GROUPID=8049&artnr=X7R-G1206+10%2F16
1
500KΩ
R-TRIMM3374
R-TRIMM3374
R1TRIM
Trimm resistor til 500KΩ
0,67 €
https://www.reichelt.de/Miniaturtrimmer/23B-500K/3/index.html?ACTION=3&GROUPID=3131&ARTICLE=146090&OFFSET=16&
1
74HC14D 74HC14D
SO14
IC1
Hex schmitt trigger
INVERTER
0,18 €
https://www.reichelt.de/ICs-74HC-SMD/SMD-HC-14/3/index.html?ACTION=3&GROUPID=2931&ARTICLE=18640&SEARCH=74HC14&OFFSET=16&
2
DTSM-6 DTSM-6
DTSM-6
PROG, RESET
Push button
0,24 €
https://www.reichelt.de/Kurzhubtaster/TASTER-9314/3/index.html?ACTION=3&GROUPID=7587&ARTICLE=44510&OFFSET=500&
1
ESP12
ESP12
ESP12
ESP
ESP8266 Wifi module 12
2,54 €
https://www.aliexpress.com/item/1-pcs-x-ESP-12F-ESP8266-ESP-12F-Remote-Serial-Port-WIFI-Transceiver-Wireless-Module-UNO/32581210212.html
1
HT7333
HT7333
SOT-89
IC2
Step Down Module (Ultra low current 4µA)
0,12 € (1,18€ / 10pc)
https://www.aliexpress.com/item/10PCS-HT7333-A-SOT89-HT7333-1-SOT-89-HT7333A-1-7333-1-SMD-7333A-1-new/32531141419.html
2
LSP11
LSP11
LSP11
LSP1, LSP2
SOLDER PAD
no costs
1
Platine
EPCU
Size 200X100, one side copper
0,58 € (1,75 €)
https://www.reichelt.de/Platinenzuschnitte/EPCU-200X100/3/index.html?ACTION=3&LA=2&ARTICLE=7408&GROUPID=7783&artnr=EPCU+200X100&SEARCH=%252A
1
Accu 18650
e.g. LG ICR18650S3 - 2200mAh, 3,6 - 3,7V Lithium Ionen Akku
3,95 €
https://www.akkuteile.de/lg-icr18650s3-2200mah/a-100629
1
18650 Holder
0,44 €
https://de.aliexpress.com/item/Hot-With-Wire-Lead-Plastic-18650-Battery-3-7V-Clip-Holder-Storage-Box-Case-Cheap-Sale/32458234409.html
Sum 10,00€ + shipping + work
Reichelt Order List: https://www.reichelt.de/my/1310317
see also file https://github.com/lh84/moisture_sensor_esp12/blob/master/bom.txt
As software you can use the source code von Zentris3
First test at 20/01/17 was pretty good with this new designed board.
I made a first prototype of the new design with etching at home. Looks und works pretty good for the first test.
First tests with prototype You can see the live data from my first sensor prototype monitored in thingspeak:
https://thingspeak.com/channels/210863/charts/1?width=1000&height=600&bgcolor=%23ffffff&color=%23d62020&results=240&type=line&update=15×cale=240
You have an idea how this sensor can be designed better? Then write me or send a request.
