BOB-4-HGI OSD Module (NTSC & PAL)

BOB-4-HG (header connector version) module for NTSC or PAL video.

BOB-4 is the 4th-generation low-cost video information overlay module. BOB-4 lets your microcontroller or PC display text and vector graphics on standard TV monitors. With huge user-definable character sets*, BOB-4 also supports bitmap graphics and multiple languages. BOB-4 generates background video on-board, or automatically genlocks to your video source and superimposes characters over the image. Printable characters and commands control BOB-4 through a fast RS-232 style data link, much like a serial printer. BOB-4 links directly to most microcontrollers. NTSC and PAL video standards are supported in a single hardware version. Field firmware upgrades are supported via PC connection.

Features:

• Simple hookup; requires just DC power, serial data, and video connections
• Prints plain ASCII text in default configuration
• High display density; up to 480x240 (NTSC) or 480x288 (PAL)
• Arbitrary font sizes and proportional font support
• Stores thousands of custom characters (off-board option ~ feature not yet available)
• Vector graphics drawing commands
• Industry-standard ANSI control protocol (ECMA-048)
• Automatic vertical scrolling
• Text crawl (single-line smooth horizontal scroll)
• Async, Synchronous, and SPI host communication options
• Automatic video mode control (local/genlock)
• Customer-configurable video standards (NTSC/PAL)
• Stand-alone operation for simple source ID, target reticle, etc.
• Software-controlled digital outputs (5)
• Consumes only 500 mW @ +5VDC
• RoHS compliant (lead free) by ~October 2006
• Extended production lifetime; no OSD chips!
• Firmware can be upgraded in the field

The BOB-4 Conscriptor PC program is provided without charge to assist customers with BOB-4 configuration. See Resources link for download. The BOB-4 Conscriptor runs on Windows PCs and offers these conveniences:

• Font editing, importing, file management (feature available, but not yet supported by BOB-4 module)
• Bitmap graphics importing and editing (feature available, but not yet supported by BOB-4 module)
• Boot script editing and file management
• BOB-4 configuration memory management
• BOB-4 firmware upgrade utility
• One-click BOB-4 module configuration (feature not yet available)

Specifications

Physical
BOB-4 is initially designed in the 30-pin SIMM form factor, 3.50 x 1.05 x 0.35 inches. A new female pin header form factor is expected late in 2006. Module weight is about 0.35oz/9.8g. Ambient operating temperature range is -40 to +85C. BOB-4 will become nominally RoHS-compliant in 4Q 2006.

Power Supply
BOB-4 requires +5VDC regulated to ±5% at 100mA typical. The power supply should be sized to accommodate 150mA or more, and protected against fault currents above 250~300mA. A low-current auxiliary +3.3VDC regulated output is available. Auxiliary supply output current adds to main supply current drain. Maximum +3.3V load current has not been characterized at this writing.

Data I/O
The data path is synchronous or asynchronous serial with BOB-3 compatible ‘standard’ rates of 1200, 2400, 4800, 9600, 19.2k, 38.4k, 76.8k, and 153.6k bits/S, using eight data bits, no parity, and one stop bit (8N1). The default rate is 9600. BOB-3 standard rates are selectable via pin strapping—see Pin Descriptions. 115.2kbps and synchronous (not yet tested) rates are also available. Arbitrary rates are selectable via software from 46bps up to 998.4kbps. Software (/) and hardware (RTS/CTS) flow control schemes are implemented, but use is not mandatory. An SPI interface option is available. The SPI port may be used for BOB-4 control or font memory expansion, but cannot simultaneously serve both purposes. Only the SPI slave mode (for BOB-4 control) is currently implemented.

Logic outputs are 3.3V CMOS except pin 20. Logic output current is 8mA max except pin 15 (16mA). Logic inputs are TTL-compatible (max logic low: 0.8V, min logic high: 2.0V) and 5V-tolerant (except pins 12, 13, 14), but hard 5V drive is not allowed during reset. Only pin 9 (RXD) offers full 5V input tolerance.

Print Speed
Small printable characters from internal fonts are normally written to display RAM within a few microseconds after the stop bit is received, so total print delay time is essentially that of the serial interface at low to moderate data rates (e.g. 521uS per character at 19,200 bits/S). BOB-4 can print more than 7,000 chars/S continuously, but large characters and graphic objects consume CPU time roughly proportional to screen area, potentially reducing this rate. Characters may not appear in the display until the next vertical scan cycle, depending on when they are written. If single-frame print timing accuracy is required, host data transmission activity should be triggered from the start of vertical blanking (logic output available) and display position should be near screen bottom. BOB-4 can message the host when vertical blanking begins.

Video I/O
BOB-4's video environment is RS-170A (NTSC) or PAL-B composite baseband, 1Vpp 75 ohms unbalanced. Y/C video (S-Video) can be accommodated with external circuitry. The video input tolerates up to 2.5VDC bias mixed with incoming video. The video output contains a small DC bias (+1V), which is common to many video sources and is well tolerated at the inputs to most video equipment. A ‘local’ video signal (black background) is generated by default if video input is not supplied, but users can enforce genlock or local video modes. Video control and timing signals are available by software command at logic-level outputs.

Character Format
Character bitmaps can be of arbitrary dimensions up to 256x256, limited only by font storage space. 62kB internal font memory is provided. External font space is defined by the size of available SPI memory chips. Proportional fonts are supported. Font depth can be one or two bits per pixel. 2bpp fonts support character outline and background features, but render as 1bpp if blinking is enabled. Fonts of assorted size and appearance are pre-loaded in font memory. Only the BOB-3 look-alike font currently includes European language support. New BOB-4 fonts can be created or imported and edited with the BOB-4 Conscriptor, a PC program supplied without charge by Decade Engineering. (Custom font loading is not possible with early release firmware.)

In BOB-3 compatibility mode, 34 columns and 15 (NTSC) or 19 (PAL) rows of characters may be displayed on overscanning monitors. 40 columns are available if the full raster is used. 304 character patterns are provided as 12x13 pixel bitmaps, including upper & lower case, italics, European language support, and a set of graphics characters useful for lines, bar graphs, etc. The character set closely replicates that of BOB-3 prior to firmware version 4, including the default RAM font (but now it’s in flash memory).

Display Features
Overlay resolution for square pixels is 320x240 in NTSC mode, or 384x288 in PAL mode. Higher pixel rates yield increased display density (up to 480 pixels/line). Only monochrome text and graphics are available. Characters are displayed by default in white with a thin halftone (reduced video intensity) outline. Halftone and black character backgrounds are optional, along with many other character rendering variations. In local video mode, a full-screen black matte background is automatically supplied. Blinking is selectable by character. Manual adjustment of overlay transparency is optional, with external circuits. The text display window may be reduced to any desired portion of the screen. Vertical scrolling is automatic. A single crawl (horizontal scroll) line can display up to 1024 characters sequentially without disturbing other display elements. The entire overlay may be toggled on or off without affecting the contents of display RAM. Writing to display RAM is permitted with display on or off. A non-volatile boot script memory stores up to 512 characters that may be used to configure BOB-4 and automatically generate a display at power-up time.

Note on compatibility with BOB-3 Systems

The BOB-4 SIMM version offers limited hardware compatibility with BOB-3. It mounts in the same socket and uses the same pins for basic functions, except power supply. If the BOB-3 socket has +5V power applied to pin 3, and nothing more than basic video and data I/O connections are deployed, then BOB-4 may be directly compatible. In all BOB-3 applications where extended functionality has been implemented, it is necessary to conduct a careful review of pinout differences. Application software compatibility is also limited. A subset of BOB-3 commands is provided in BOB-4, but most customers will benefit from revising application programs to use the new BOB-4 command set.

* This feature is not present in early product