EVE FAQs -Interface

What interfaces does EVE support?

FT80X: Standard serial interfaces to the host MCU include: SPI up to 30MHz or I²C clocked up to 3.4MHz.
FT81X: Standard serial interfaces to the host MCU include: QSPI up to 30MHz.

How do you design EVE with minimum external components?

EVE can be designed into a system without the need to add an external crystal component. EVE has an internal oscillator that is enabled by default upon power on. The frequency of the internal oscillator is 12MHz ±5.6% across operating temperature (-40° to 85°C).

What is crystal frequency supported?

When external crystal component is used, the crystal component should be 12MHz.

What connectors do I require to connect with the red connectors on the VM800P?

These connectors are 2×8 way Micro-MaTch connectors and allow for expanding the IO of the VM800P to add interfaces such as Ethernet, RS485, relays etc. via the SPI port of the ATMEGA328P.

http://www.te.com/catalog/minf/en/439

Can the FT8XX access an SD card directly?

No. For designs requiring additional memory for storing objects such as images and audio files the additional memory must connect to the MCU. This allows for extra flexibility as the MCU can access the memory for other non-EVE associated files without going via the FT8XX and as such the extra system memory becomes general purpose. This architecture also allows for the additional memory to be either USB, SD Card or other formats.

Can EVE work with Intel 8080 Interfaces?

No. Current devise in the series are designed for RGB only

Can I adjust the FT8XX pinout in software?

Yes. The FT8XX contains a function called swizzle which allows the assignment of the Red, Green and Blue data lines to be changed. The user can either swap an entire bank of colour pins or reverse the bit order. To make the swaps the application code must access the REG_SWIZZLE register.

Does the microcontroller need to handle raw, touch-screen input?

No, the raw touch screen information is acquired and processed and updated in the respective register for the MCU to read. EVE does the noise filtering for the resistive touch-screen. The x, y data is loaded into registers to be read by the MCU. In addition, a resistive location can be defined and mapped to a specific character (i.e. a specific alpha-numeric) so that this specific character is transferred from the FT8XX to the MCU, such that the MCU need not execute any parsing functions.

Can the FT8XX run from an FPGA?

Essentially yes. The FT8XX at its most basic level can be considered as a QSPI (FT81X only) or SPI peripheral to a host controller. Whether that hosts is in the MCU or FPGA is up to the designer.

When I write to the FT8XX do all instructions take the same time to execute?

Although each instruction sent over QSPI (FT81X only) or SPI interface, this cannot be guaranteed as not every instruction does the same thing. E.g. some instructions must fetch objects from object RAM while others draw primitives on the fly. Widget instructions are like zip files which must be extracted to create a full list of commands for the display list.