Build a Wireless Soil Moisture Sensor with built-in Micro Energy Harvester

Published  August 1, 2023   


In today's rapidly evolving world, technological advancements continue to reshape industries, with agriculture and gardening being no exception. Imagine having the ability to effortlessly monitor soil moisture levels in your garden or farm remotely. In this project we are aiming find a solution for that. This innovative solution utilizes a capacitive soil moisture sensor, along with long range LoRa communication without the hassle of manual recharging or battery replacements.

This project utilizes ADP5091, an ultralow power energy harvester PMU with MPPT and charge management from Analog Devices for charging the internal battery from solar energy. We can either use a LiPo battery or a super capacitor for storing the energy. For the controller, we have used the popular ATMega328 MCU, which is widely used in Arduino boards. The moisture sensing is done using a capacitive sensor built around a TLC555C chip. RFM69W module is used for communication. The sensor and LoRa module will only be turned on when necessary. This will help us to reduce energy usage during deep sleep period.

Code File

PCB Gerber File

Components Required

Value Package Manufacturer Digikey Part Number Datasheet Link    Quantity
10nF C603 KYOCERA AVX 478-KGM15AR71H103KTCT-ND   Datasheet 1
0.1uf C603 Samsung Electro-Mechanics 1276-1935-1-ND   Datasheet 8
470pf C603 Walsin Technology Corporation 1292-1438-1-ND   Datasheet 1
4.7uf C603 Samsung Electro-Mechanics 1276-1784-1-ND   Datasheet 2
10uF C603 Murata Electronics 490-GRM188R6YA106MA73JCT-ND   Datasheet 1
18pF C603 KEMET 399-C0603C180K4HAC7867CT-ND   Datasheet 2
LED LED_0603 Harvatek Corporation 3147-B1931NB--20C007614U1930CT-ND   Datasheet 1
1N4148WS SOD-323 Diodes Incorporated 1N4148WSF-7DICT-ND   Datasheet 1
22uH IND_VLS3015CX-220M-1 TDK Corporation 445-181504-1-ND   Datasheet 1
5.9M R0603 Vishay Dale 541-5.90MHCT-ND   Datasheet 2
150K R0603 Vishay Dale 541-150KHCT-ND   Datasheet 1
4.7M R0603 Vishay Dale 541-4.70MHCT-ND   Datasheet 1
18M R0603 YAGEO 13-RC0603JR-0718MLCT-ND   Datasheet 1
4.7R R0805 Vishay Dale 541-4.7APCT-ND   Datasheet 1
330R R0603 Bourns Inc. CR0603-JW-331ELFCT-ND   Datasheet 1
56K R0603 Vishay Dale 541-56.0KHCT-ND   Datasheet 1
10k R0603 Stackpole Electronics Inc RNCP0603FTD10K0CT-ND   Datasheet 6
1k R0603 Stackpole Electronics Inc RNCP0603FTD1K00CT-ND   Datasheet 1
4.22M R0603 RMCF0603FT4M22CT-ND RMCF0603FT4M22CT-ND   Datasheet 2
1.6K R0603 YAGEO 311-1.6KGRCT-ND   Datasheet 1
1M R0603 Walsin Technology Corporation 1292-WR06X105JTLCT-ND   Datasheet 1
6.65M R0603 Vishay Dale 541-6.65MHCT-ND   Datasheet 2
3.3M R0603 YAGEO 311-3.3MGRCT-ND   Datasheet 2
100K R0603 YAGEO 311-100KHRCT-ND   Datasheet 1
442K R0603 YAGEO 311-442KHRCT-ND   Datasheet 1
S8050 SOT-23 Micro Commercial Co MMSS8050-H-TPMSCT-ND   Datasheet 2
Solar_Cell Solar Cell SM141K04LV-ND ANYSOLAR Ltd SM141K04LV-ND   Datasheet 1
ADP5091 LFCSP-24-1EP Analog Devices Inc. 505-ADP5091ACPZ-2-R7CT-ND   Datasheet 1
ATmega328-AU TQFP-32_7x7mm_P0.8mm Microchip Technology ATMEGA328-AU-ND   Datasheet 1
TLC555C SOIC-8_3.9x4.9mm_P1.27mm Texas Instruments 296-1336-5-ND   Datasheet 1
16MHz Crystal_3225 YIC 3155-16M18PX/XT324-10/10CT-ND   Datasheet 1