Embedded Modules Explained
The term "Embedded Module" (or "Embedded System") is appearing more and more frequently in the electronics industry, and more people are encountering these products in their work. In fact, we work with these modules almost daily without being aware of it. What lies behind the term Embedded Module and where we encounter these systems everywhere will be explained simply in this article.
This article does not deal with the technical details of embedded modules. It is about explaining them for readers who do not have deep technical knowledge about modular systems and have no idea about embedded modules yet.
What is an Embedded Module?
An "Embedded" module (often also called SoM, System on Module) is essentially a small ready-to-use computer that is used to perform specific tasks and is designed to control and manage other, usually larger devices. The term "Embedded" means that these small computers are "embedded" and firmly integrated into another circuit. To get an idea of these small computers, here is a 3D model of a pluggable module:
The use of the term "module" emphasizes the idea of interchangeability and versatility of the components. Developers can integrate them into various electronic systems to add specific functions without having to redesign the entire system. This modularity speeds up the development of electronic devices through defined connector standards and facilitates the maintenance and updating of existing devices.
Components of the Module
One of the advantages of using an embedded module is the plug-and-play concept. All components required for operation are placed and prepared on the module. The main components of the module are the processor, the memory, the data storage and the voltage regulation.
1. Processor (CPU)
The processor (often also called Central Processing Unit) is often referred to as the "brain" of the device. It processes all data and performs calculations. The processor is responsible for executing applications and controlling the device. The more powerful the processor, the faster it can complete tasks. There are different types of CPUs. Processors based on the ARM architecture, for example, are used in smartphones (e.g. Android or iPhone). Processors of the x86 architecture are found in most desktop computers and laptops.
2. Memory (RAM)
The RAM (or Random Access Memory) is a very fast memory where the processor stores the currently needed data and calculation results. Unlike data storage (eMMC), it loses its data when disconnected from the power supply. The more memory available, the more data the processor can store there and does not always have to access the much slower data storage. The size of the memory determines, for example, how many browser tabs or programs can be opened simultaneously on the phone or computer.
3. Data Storage (eMMC)
eMMC stands for "embedded MultiMediaCard". The eMMC is comparable to a permanently installed SD card and enables data storage. It retains this data even when not powered. It is functionally comparable to the hard drive in a computer. In smartphones and certain laptops, the eMMC is used as the main storage for the operating system and all pictures, music, documents... Occasionally, SPI flash memory (e.g. NOR flash) is also used as an alternative, which is cheaper but also significantly slower.
4. Power Supply (PMIC)
The PMIC (or PowerManagement Chip) takes care of the various voltages required by the individual components. Each component (CPU, RAM, eMMC,...) requires a different supply voltage than the other chips. The PMIC provides these different voltages to the individual components. Thus, the module usually only needs to be supplied with a certain voltage and not with many different ones.
A creative example
You can imagine the whole thing like an office workplace. The employee takes on the role of the CPU. He has a tray (memory) on his desk with important documents he is currently working on. If he needs new documents and wants to file the processed ones, he first has to go to his filing cabinet (eMMC) and look for them, which takes longer than taking the documents from the tray. The coffee machine supplies him with coffee on the side so that he has enough energy for his work (PMIC).
Designs of Embedded Modules
Modules come in various sizes and shapes. On the back of the modules are connectors or pads that allow it to be mounted on a suitable carrier board or device. There are three types of module connectors:
Proprietary Connectors
Proprietary connectors are special connector types that are only used by one company or only in one product. They do not quite match the modular approach of embedded modules, as the modules cannot be replaced by others and only this module type can be assembled on the board. For a different module, the board then needs to be adapted.
Standardized Connectors
Standardized connectors are generally accepted and widely used connector types. They were developed by standardization organizations and companies and thus enable the operation of different modules of the same standard on the same card. Well-known examples are the SMARC and COM Express specifications. The standards allow alternative or newer versions of the module to be used if they comply with the same connector standard, which facilitates upgrading and replacing modules and follows the modular approach. This can be compared to upgrading a computer to a new faster processor.
Soldering Assembly
In soldering assembly, there are no connectors on the back of the module, but pads that allow soldering onto the base plate. Replacing defective modules is hardly possible here and the entire system must be replaced. However, these modules are very space-saving and very firmly mounted, which may be necessary in some environments.
Operating the Module
Basically, the embedded module can be operated like any other computer. The module is mounted on a carrier board (with all required interfaces) and supplied with voltage. The memory contains an operating system (e.g. Windows or Linux), which boots up after switching on and then takes over certain tasks. There are modules that allow control via mouse and keyboard and also offer display output with a familiar interface (e.g. Windows 11). Other modules have no display output and are only controlled via a serial connection (text inputs).
Areas of Application of Modules
Embedded modules are found in more devices than one might suspect at first glance. Here is a short list of application areas:
- Smart TVs
- Smart Home devices
- Cars
- Medical devices
- Industrial automation
- Single Board Computers (mini computers)
- IoT devices
- Consumer electronics
- Defense and aerospace technology
- Retail systems
- Energy and environmental monitoring systems
Advantages and Disadvantages
Finally, some advantages and disadvantages that speak for or against the use of embedded modules.
Advantages
Compact Size: Embedded modules are typically small and space-saving, making them ideal for use in devices with limited space.
Reliability: Since they are developed for specific tasks, embedded modules often work very reliably and stably.
Accelerated Development: Manufacturers can use prefabricated embedded modules to shorten the development time for new products.
Cost Efficiency: The mass production of embedded modules can be more cost-effective than the production of custom solutions.
Flexibility: They are often modular and interchangeable, which facilitates the adaptation and updating of devices.
Disadvantages
Limited Customizability: Embedded modules are not as flexible as custom solutions and can limit adaptability in certain applications. Through multiplexing, however, the modules are still very adaptable.
Dependence on Manufacturers: Proprietary embedded modules can lead to companies being heavily dependent on a single manufacturer.
Limited Update Options: In some cases, updating embedded modules can be difficult or expensive, especially if they are firmly integrated into a device.
Possible Compatibility Problems: If embedded modules are not carefully selected, there may be compatibility problems with other system components.