HardLabs

RS485 Soil moisture sensor

Miceuz·rs485-moist-sensor

RS485 Soil moisture sensor PCB layout, top view — open source AVR/Arduino board by Miceuz

About the RS485 Soil moisture sensor PCB

RS485 Soil moisture sensor is an open source AVR/Arduino PCB design by Miceuz, published on GitHub under the Apache-2.0 license. It is a 4-layer board measuring 18 × 149 mm, with 29 components from 17 distinct parts.

Its main chip is the ATTINY441-SSU, from the AVR/Arduino family. Other key parts include the SN65HVD72 and MCP1702. By type, the board carries 9 capacitors, 9 resistors, 3 ICs, 3 diodes, 2 connectors and 1 transistor.

It belongs with the sensors designs in this gallery.

From the project

Digital (RS485 - based) soil moisture and temperature sensor

A version of I2C soil moisture sensor with several updates - antistatic protection, local voltage regulation and RS485 networking.

This is a contact-less capacitive soil moisture sensor, a continuation of my I2C soil moisture sensor. This particular version of the sensor is suited for more professional installations where long cable runs is a requirement. It adds a local voltage regulator to mitigate the voltage drop and RS485 transceiver to accommodate long wires, also reverse polarity and an additional ESD protection level is added.

Main components on the RS485 Soil moisture sensor

ATTINY441-SSUSN65HVD72MCP1702

RS485 Soil moisture sensor bill of materials (BOM)

29 components, 17 distinct parts.

QtyPartRefs
1
ATTINY441-SSU
MICROCHIP
IC1
1
SN65HVD72
TEXAS INSTRUMENTS
U1
1
MCP1702
MICROCHIP
U2
1
Q_PMOS_GSD
NXP
Q1
1
16MHz
MULTICOMP
X1
1
CONN_02X03
P1
1
CONN_01X04
?
P2
1
NCP18XH103F03RB
MURATA
TH1
2
RB751S40
ON SEMI
D1, D2
1
NUP4004M5T1G
ON SEMICONDUCTOR
D4
2
13p
MULTICOMP
C1, C2
5
1u
C3, C6, C7, C8, C9
2
1n
C4, C5
3
10k
R1, R3, R9
1
10k 0.1%
PANASONIC ELECTRONIC COMPONENTS
R2
1
330
R4
4
1M
R5, R6, R7, R8

RS485 Soil moisture sensor design files

The KiCad project lives in the Miceuz/rs485-moist-sensor repository on GitHub; these links point at the commit this page was built from.

RS485 Soil moisture sensor: common questions

What microcontroller does the RS485 Soil moisture sensor use?

The RS485 Soil moisture sensor is built around the ATTINY441-SSU, from the AVR/Arduino family.

How big is the RS485 Soil moisture sensor PCB?

The RS485 Soil moisture sensor measures 18 × 149 mm, has 4 copper layers and is 1.6 mm thick.

How many components are on the RS485 Soil moisture sensor?

29 components, from 17 distinct parts. The full bill of materials is listed on this page.

Where can I download the RS485 Soil moisture sensor design files?

From the Miceuz/rs485-moist-sensor repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the RS485 Soil moisture sensor design in my own project?

Yes, under the terms of its Apache-2.0 license, which Miceuz chose for the repository.

Can I test firmware for the RS485 Soil moisture sensor without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug AVR/Arduino firmware against it before you order a PCB.

More boards in rs485-moist-sensor

Similar boards