It also includes adding secondary displays to products that already have a primary display, such as time and date information to mobile phones or a permanent battery indicator. Electronic paper displays also have applications in watches and clocks, public signage, advertisements and medical devices. When adding such displays to a product it is helpful to first evaluate the performance before spending time and money on building a prototype. In this article, we look at an evaluation kit from Dialog Semiconductor designed for this purpose. It provides a complete hardware and software development environment enabling quick evaluation of the E Ink electronic paper technology and accelerating the development process. It includes a sample electronic paper display from E Ink and uses a family of display driver ICs from Dialog Semiconductor.
Design the display
This evaluation kit is designed for product managers to evaluate and develop an electronic paper display subsystem prior to creating the actual display for their product design. The evaluation kits provide a full hardware and software development environment to allow for fast device evaluation and system design. With the E Ink evaluation kit you can:
* Assess the suitability of the E Ink technology for a given product concept.
* Quickly evaluate the performance of the display (for example, in terms of its
contrast ratio, look and feel, and transition speed).
* Design the display (particularly its size, segmentation and other parameters).
* Direct connection to an alternative microcontroller system.
* Evaluate different driving waveforms.
* Start the design of the software for the microcontroller being used in the system.
By being able to carry out these tasks in advance, it is possible to understand how an E Ink display can potentially add value to a product, decide whether or not to proceed with an engineering prototype, and carry out system development before the prototype hardware is ready.
Development environment
The kit comes with a sample E Ink electronic paper display, a CD containing the software, the evaluation board and USB cable (which can be used to power the board). The E Ink display is a sample that includes typical icons such as capacity meters, seven segment digits and many others. Controlled via a USB interface connected to a PC or directly to a microcontroller as part of a larger development environment, a range of interfaces on the evaluation board allows connection to different displays using both packaged and bare-die format solutions. As such the evaluation board can also connect to almost any display from E Ink.
Dialog Semiconductor and EPN are giving away FIVE of the evaluation kits described in this article. To qualify for the prize draw simply enter the reference number below on our web site (www.epn-online.com) and press the Get Datasheet button
The software includes a Windows-based graphical user interface used to build a software model of the display and then generate the software code required for the display driver IC to drive the E Ink display. The designer can import a bitmap display image and then define the scheme for driving each segment in the display along with the sequencing required to fully develop and evaluate the final system.
By controlling various timing parameters the user can optimise the design for specific applications and different working environments. The optimal value for these parameters can depend on many factors such as the size of the segment, the operating temperature, the desired transition frequency, etc. The software allows the user to play with different waveforms and visually evaluate the effects of each.
The process of connecting and setting up a new display for a simple numeric ‘memory gauge' display is shown in Figure 1. In this example, the display is 3x1.5cm in size, with 30 active segments. The user enters the number of outputs and loads the bitmap image of the display to be used. The kit then allows the user to map the segments of the display to the connected segment outputs interactively. When all areas are mapped to segment outputs, the mapping can be tested. Clicking on any segment will then highlight that particular segment in the software, and then also turn the corresponding segment of the display either black or white.
Engineering development
Once the segment mapping is done, it is possible to create sequences of slideshows in which the segments are activated dynamically. This allows sequences of mouse clicks to produce a series of displays both for demonstration purposes as well as for engineering development. For example, one can simulate the second hand of a clock just to see what it looks like when the digits change on that particular display. When doing so it may look better to update a region of the display or it may look better to reset the display and then update the whole thing. The waveforms can be fine-tuned using a waveform editor menu. The developer can test the visual performance of different electrical waveforms on the sample display. After using the kit to understand and simulate the functionality of the display the designer is in a good position to move to the next step, which is to build a first prototype of the system. Without an evaluation kit like this product developers would need to make a lot of assumptions about the behaviour of the display and its control circuit before making a prototype.
Conclusion
This memory gauge example shows how a designer or product marketing manager can use the E Ink evaluation kit to speed development of their electronic paper product. This E Ink evaluation kit is important for the display industry because it facilitates the evaluation of new display concepts and even new ways to communicate. For example, signs indicating pricing at retail stores, battery levels of power tools, schedules at train stations, and delivery addresses on post boxes are all traditionally paper based but would benefit from an electronic alternative.
Piccap:The evaluation kit provides full hardware and software development support
Figure 1: A memory gauge display
