IoThing Digital is an open source digital I/O module with two high-power Omron G5Q-14 relays and two isolated digital-input channels (based on Texas Instruments ISO1211). Designed for ease of use with Raspberry Pi, Arduino, and other embedded platforms, it accepts digital input of both DC and AC signals to support a broad range of input-voltage levels. You can choose the voltage range, be it 60 VDC, 220 VAC, or anything else up to 300 V. IoThing Digital also includes a DC-DC converter, EEPROM for storing configuration data, and a slot for mikroBUS connectivity and to attach microcontroller modules.

Compatible With Popular, Third-Party SBCs & MCU Boards

Between our five adapter shields, you can use IoThing Digital as an add-on module for many popular third-party microcontroller boards, including Arduino Nano, STM Nucleo-32, Adafruit Feather, SparkFun Thing Plus, Particle, Teensy, Raspberry Pi PICO, and MikroElektronika MINI. You can find documentation for these adapters on our website and in our GitHub repository.

We also offer an RPi-to-mikroBUS adapter that allows you to connect your Raspberry Pi single-board computer (SBC) to the mikroBUS connector on IoThing Digital or to other I²C modules. And, if you’re working with a Raspberry Pi 3A+, you will be glad to hear that IoThing Digital adheres to the same 65 x 56 mm form factor.

Custom System-on-Module (SoM) Boards Also Available

During this campaign, we are also making three custom SoMs available in limited quantities: one with an LPC824 microcontroller, one with a a SAMD21 microcontroller, and one with an STM32F411 microcontroller. Technical documentation for all three can be found in our GitHub repository.

The LPC824 Lite Microcontroller Board

• Cortex-M0+
• Frequency: 30 MHz
• Flash memory: 32 kB
• RAM: 8 kB
• Interfaces: SPI, I²C, USART, and SWD
• External connectors: mikroBUS & I²C
• Compatibility: LPCXpresso824-MAX
• Dimensions: 28.6 x 25.4 mm
• Datasheet

The SAMD21 Lite Microcontroller Board

• Cortex-M0+
• Frequency: 48 MHz
• Flash memory: 256 kB
• RAM: 32 kB
• Interfaces: SPI, I²C, USART, USB, and SWD
• External connectors: mikroBUS & I²C
• Compatibility: Adafruit Feather M0
• Dimensions: 28.6 x 25.4 mm
• Datasheet

The STM32F411 Lite Microcontroller Board

• Cortex-M4F
• Frequency: 100 MHz
• Flash memory: 512 kB
• RAM: 128 kB
• Interfaces: SPI, I²C, USART, CAN, LIN, USB, and SWD
• External connectors: mikroBUS, I²C, and USB
• Compatibility: BluePill, MicroPython pyboard PYBv1.1
• Dimensions: 28.6 x 25.4 mm
• Datasheet

Perfect for Professionals & Hobbyists

IoThing Digital is perfect for engineers working on distributed or decentralized control systems, IoT and IIoT product designers, and amateur developers – anyone who needs a reliable module upon which to build compact, embedded control systems. IoThing Digital can be used to automate everything from thermometers to windows to heating systems to full-scale smart homes, smart gardens, and smart farms.

Comparisons

Efficient, Compliant, Independent ISO1211 Inputs

For its inputs, IoThing Digital uses the Texas Instruments (TI) ISO1211 instead of a traditional optocoupler-based solution. The primary benefits of this solution include:

1. Reduced power dissipation, which leads to a significant reduction in the heating of the board

A traditional board (heating to 84.1°) compared to an ISO1211-based board (heating to 44.9°)

2. Guaranteed compliance with IEC 61131-2

3. Channel independence, which prevents damage to one channel on the field side (due to a short circuit, for example) from impacting any of the other channels

Features & Specifications

• PCF8574 chip with I²C bus for relay control and digital signal input
• Supports 100 kHz and 400 KHz on I²C bus
• Selection of one of eight addresses on the I²C bus for the PCF8574 using jumpers on the bottom-side of the module, default address is 0100 010x010x
• Grove connector for external module with I²C bus
• Compatible with major well-known microcontrollers
• 2 SPDT relays
• Current consumption of each relay is less than 80 mA
• Characteristics for resistive load: 3 A 30 VDC or 3 A 250 VAC
• Dielectric strength: 4 kV VAC, for 1 minute between coil and contacts; 1 kV VAC, for 1 minute between contacts of the same polarity
• Compliant to IEC 61131-2; Type 1, 2, 3 characteristics for 24 V insulated digital inputs
• You can enter the values of two digital signals, from 9 V to 300 V, DC and AC
• Accurate Current Limit for Low-Power Dissipation – 2.2 mA to 2.47 mA for Type 3
• The maximum insulation voltage (up to 60 s) is 3600 VPK
• Maximum working insulation voltage: AC – 400 VRMS, DC – 566 VDC
• Reverse polarity protection
• Modules you can install with the mikroBUS bus:
  • our modules (SoM Lite series and other modules),
  • Click® modules from MikroElekronika
• Power supply: non-isolated, 9-36 VDC
• Size: 65 x 56 mm. The format of the module corresponds to the popular format of the Raspberry Pi 3A+, which greatly simplifies its use with the Raspberry Pi.

IoThing Digital Pinout

Support & Documentation

You can find technical details and board schematics in our product datasheet, documentation for our adapter shields on our website, and much more in our GitHub repository. You can also reach out using the Ask a technical question link below.

Manufacturing Plan

IoThing Digital has already been tested and deployed in several projects. We produced a trial batch of modules for this purpose and used them to approve the design of the board. Our PCBs will be manufactured in China and tested there before being shipped to the US for fulfillment. We have longstanding and successful working relationships with several contract manufacturers, including the one with whom we currently expect to partner on IoThing Digital production.

We are working closely with a number of distributors and vendors to accelerate component acquisition so we can manufacture IoThing Digital as quickly as possible despite current component-availability challenges.

Fulfillment & Logistics

After testing and packaging the production batch of IoThing Digital boards, we will send them on to Crowd Supply’s fulfillment partner, Mouser Electronics, who will distribute them to backers worldwide. You can learn more about Crowd Supply’s fulfillment service under Ordering, Paying, and Shipping in their guide.

Risks & Challenges

The first batch of IoThing Digital has already been manufactured and tested, so we have no concerns about issues with the module itself. In that respect, risk to backers is low. However, the global chip shortage—caused in part by the COVID-19 pandemic—is such that we are constantly on the lookout for possible component-availability challenges. Should we encounter any such issues, we will inform you by way of a campaign update.

While we currently anticipate no production issues, a surge in COVID-19 incidence could cause delays in the fabrication or assembly of IoThing Digital PCBs. In the event of significant delays, however, we are prepared to change manufacturers in order to mitigate the issue. And of course, if we are somehow unable to complete IoThing Digital fulfillment, we will offer backers a full refund.