Demand Peripherals     Robotics and Automation Made Easy

TIF: Text Interface Card

The Text Interface card (TIF) has the basic user interface elements needed by robots or other automation. The card itself has two LEDs, a rotary encoder with push button, and a piezo beeper. It also has connectors for a 4x5 keypad and a HD44780 style text display.

The TIF card's API is described here: /peripherals/tif.html.


- Two LEDs, piezo beeper, and a rotary encoder
- Connector for a four-by-five keypad
- Connector for character LCD module
- User space Linux device driver (part of dpdaemon)
- Uses the ESPI 7474 circuit for reliable operation
- Requires one slot on a Baseboard FPGA card



All of the user interface elements on the TIF connect to the FPGA over a 16-bit output shift register and an 8-bit input shift register. The shift registers are clocked using the ESPI quadrature clock scheme for reliable operation over ribbon cable.

The schematic and layout of the TIF are shown below. The Eagle schematic and board files are available here: tif.sch and tif.brd. The bill-of-materials is available here: tif.txt.