- Eight HV Digital Inputs 8-Layer Stackable HAT for Raspberry Pi
- Eight digital opto-isolated inputs 3V-24V or 48V-240V AC/DC
- Eight layer stackable to 64 inputs
- LED Indicators on each input
- Pluggable Connectors 26-16 AWG wires
- Separate low/high voltage connectors for each input
- RS485 Transceiver
- Eight Inputs for Raspberry Pi
- Command Line Driver
- Python Library
- Node-Red nodes
- OpenPLC module
A power LED shows when power is applied to the board. One LED for each input shows when the input is activated.
DIP SWITCH CONFIGURATION
A six position DIP switch is used to activate the RS485 port and to select the position of the card in the stack, if multiple cards are used.
The 16 Solid State Relay Card has an RS485 port which can be driven from the Raspberry Pi. Set both to ON to connect the RS485 port to USART1 of the Raspberry Pi.
When DIP Switches are ON, Raspberry Pi can communicate with any device with an RS485 interface. In this configuration the card is a passive bridge which implements only the hardware levels required by the RS485 protocol.
When DIP Switches are OFF, the Raspberry Pi GPIO pins can be used for other functions. If multiple cards are stacked, only one card can have the DIP Switches ON.
The first position on the DIP switch is the RS485 line terminator. Set it to ON if the card is last on the RS485 chain.
- Power Supply: 5V/8A pluggable connector with reverse polarity protection
- On board resettable fuse: 3A
- Opto-isolated Digital Inputs:
- Input Forward Current: Typical 5 mA, maximum 50 mA
- Low Voltage Input Series Resistor: 2.2K
- High Voltage Input Series Resistor: 120K
- Isolation Resistance: Minimum 1012 Ω
- Four M2.5x18mm male-female brass standoffs
- Four M2.5x5mm brass screws
- Four M2.5 brass nuts
- Plug your 8-INPUTS card on top of your Raspberry Pi and power up the system.
- Enable I2C communication on Raspberry Pi using raspi-config, instructions here.
- Install the card software from github.com:
- ~$ git clone https://github.com/SequentMicrosystems/8inputs-rpi.git
- ~$ cd /home/pi/8inputs-rpi
- ~/8inputs-rpi$ sudo make install
~/8inputs-rpi$ 8inputs -h
The program will respond with a list of available commands.
Investigated a multitude of different options to read digital input signals until I discovered Sequent Microsystems HATs. This was the most practical and easiest solution out there, and as a plus supports a wide range of input voltages all the while optically isolating each input.
Using 3 of these together with / in the following order:
- 1x Waveshare SIM7600G-H LTE HAT
- 3x SM HV digital input HAT
- 1x SM 8-relay 4A/120V HAT
- Raspberry Pi 5 + Raspberry Pi 5 active cooler + RTC battery
- 1x Pimoroni NVMe HAT
Used to monitor (ON/OFF) reed contacts (5v) / motion sensors (12v) in parallel of an analog alarm system, and to arm / disarm the alarm system using SMS + OTP.
Sequent Microsystems is my new first choice for Raspberry Pi HATs.
This card can read any input from 3V up to 240V. Separate connectors for low or high voltage. All inputs are optoisolated. Super