Create, command, and innovate like never before with eINK display and STM32F446RE

eINK Click is an adapter Click board™, used to interface a compatible eINK display with the host MCU. The most distinctive feature of the eINK displays is their very low power consumption and the ability to retain the information, even after disconnecting from the power source. The power is consumed only when the display content is changing. The Click board™ comes shipped with the 172x72 eINK display, driven by the integrated SSD1606 controller and it can display 4 shades: black, dark gray, light gray and white. The same type of display is used on the popular Kindle E-readers. The eINK is a reasonably new technology with a promising future. The displayed content does not degrade when exposed to direct sunlight, the display actually behaves like a real paper; it is more readable when there is more light hitting its surface. There is a wide range of applications, where eINK can be implemented: it can be used for very low power consumption applications that require display output, such as mobile phones and wearables, industrial and packaging applications, electronic reading and writing, electronic shelf labels and similar

applications that can utilize this type of display. The working principle of the eINK display is rather simple: there are black and white pigments trapped inside the microcapsules, which are dispersed in a clear fluid between two electrodes. The white pigments are positively charged, while the black pigments are negatively charged. When the electromagnetic field is formed between the electrodes, the pigments get repelled or attracted to the electrodes, depending on the field orientation. This results in bright or dark pigments being positioned towards the bottom or top surface of the microcapsule. When the black pigments are positioned on the top surface of the microcapsule, it is observed as the black pixel, and vice versa. It is also possible to position the pigment charges so that each color occupies one half of the microcapsule top surface and that is how gray shades are produced. The display included with the eINK click is the EA-EPA20-A, a 2 inch,172x72 pixels ePAPER display with the integrated SSD1606 driver/controller, from Electronic Assembly. This display uses the SPI communication protocol for the communication

with the host MCU. This display features inherently wide viewing angle and high contrast, as well as good readability in daylight conditions. The click board™ itself carries the supporting electronics, used to provide all the necessary voltages for the proper operation of the EPA20-A display. The SSD1606 pins are routed through the flat cable of the display and connected via the 24pin, 0.5mm ZIF connector on the click board. From there, the command and data lines are routed to the appropriate pins on the mikroBUS™ of the eINK click. The eINK click also contains the LM75 thermal sensor, which uses I2C protocol to communicate with the SSD1606 driver IC. This is required for thermal compensation of the display, so it can be operated in a wide temperature range, from 0°C to +50°C. The total power consumption of this device is very low. The power is only required when rearranging of the microcell pigments is required, while no power is required to sustain the content of the display. The display retains the content, even when the power is disconnected. The click board and the display are powered via the 3.3V rail of the mikroBUS™.

Nucleo-64 with STM32F446RE MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin

headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is

provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.