Before designing an IoT device, there are several things to consider.
IoT hardware mainly consist of three elementary parts: A microcontroller, one or several peripherals like sensors displays and networking modules, and some kind of power supply. In order to create a working circuit, these three parts will have to inter-work within their individual specs.
Compatibility between microcontrollers and peripherals essentially depends on two key factors related to their electrical characteristics:
• Supply voltage
and
• logic level.
Common options for both supply voltage and logic (data) voltage level are 3.3V and 5V.
Older sensor designs as well as power hungry peripherals generally require a 5V power supply. Independent from the supply voltage being 5V, there are cases where logic level required by the sensor will be at 3.3V. It’s a mixed bag so to say.
However microcontrollers are designed to only either run on 5V or 3.3V without being able to provide different logic levels for communication with potential periphery by default.
Usually 5V microcontrollers provide 5V logic level interface whereas a 3.3V microccontroller provides a 3.3V logic level interface.
This means that during the design process of an IoT device most of the effort goes into considerations on how to match individual sensors to individual microcontrollers while providing the correct power supply voltage to both.
There are sensors that would tolerate both 3.3V and 5V each power and logic, but often enough there are cases where there would be the need of dual power supply, means one for the microcontroller and a different one for the sensor.
Possible Scenarios:
Matching Voltage and Logic Levels:
This is the ideal scenario for direct connection. If both the microcontroller and sensor operate on the same voltage (e.g., 3.3V) and share compatible logic levels, they can connect directly without any additional components.
Mismatched Voltage but Compatible Logic Levels:
This situation is common and requires careful consideration. While the logic levels might be compatible, the voltage difference needs to be addressed. Voltage regulators can be used to convert the voltage from one level (e.g., 5V) to the other (e.g., 3.3V) to power the sensor.
Mismatched Voltage and Logic Levels:
This scenario requires additional circuitry for safe interaction. Logic level shifters can be used to convert the logic levels of the signal between the two devices. This ensures the signal received by the sensor is within its acceptable logic level range, even though the supply voltage might be different.
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With all that said – wouldn’t it be nice to have a design that would allow to match any microcontroller with any peripheral, independent from their specs? Plug and Play so to say..
Here is where Motherbyrd comes in.
The name obviously derives from the term Motherboard, common in the PC world while the “y” stands for μ as in μC (Microcontroller).
A Motherboard typically applies power as well as peripheral interfaces to a Computer CPU, making sure that any periphery like PCI cards, SCSI, USB and the like can be connected to the CPU. Another benefit of Motherboards is the provision of suitable hardware connectors for the respective external HW.
Motherbyrd like any Motherboard is an interface module specifically for μCs that can mix and match any processor with any peripheral. While microcontrollers typically provide rogue connectivity, Motherbyrd as a HW extension is equipped with industry standard (JST) connectors as well as screw terminal blocks for hassle- free mounting of peripherals.
Motherbyrd adopts the concept of a PC motherboard to the μC world. It provides IO extensions to the microcontroller which normally would have to be individually engineered, thus saving development time overall.
Features:
Unified interface to the microcontroller
Multiple bus interfaces (SPI, I2C, UART) towards external
Individual voltage levels per interface, power and logic, software programmable
HW Libraries and Arduino board definition