BOB-3 Video OSD / On Screen Display Module

  BOB-3 video character overlay generator module

This product has been discontinued. Please see BOB-4.
BOB-3 is Decade's third-generation low-cost videotext overlay module. BOB-3 lets your microcontroller or PC display up to 680 characters on standard video monitors and TV sets. With 63 user-definable characters, BOB-3 supports pseudo-graphics and multiple languages. BOB-3 generates video on-board, or automatically genlocks to your video source and superimposes characters over the image. Printable characters and commands control BOB-3 through a fast RS-232 style data link, much like a simple serial printer. BOB-3 is compatible with most microcontroller chips and modules, including the BASIC Stamptm. PAL video compatibility is optional at ordering time.

While it is upward-compatible from BOB-II in most respects, BOB-3 offers a number of important advances:

Here's a screenshot that shows some of BOB-3's capabilities. Note that small caps replace italics in V4 firmware. See XBOB for an expanded version of BOB-3 that is better for many PC-based applications, and for initial BOB-3 module application development.

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Suggested Applications

[Bullet] Remote Video Inspection & Test [Bullet] Industrial Process Monitor
[Bullet] Scientific Experiment Monitor [Bullet] Home Automation
[Bullet] Remotely Piloted Vehicles [Bullet] Robotics
[Bullet] Teleoperated Mechanisms [Bullet] MATV ~ Pay TV
[Bullet] CCTV Security & Surveillance [Bullet] Electronic Signs
[Bullet] System Status Display [Bullet] ATV ~ Amateur TV
[Bullet] Gaming [Bullet] Race Cars
[Bullet] R/C Models [Bullet] Law Enforcement

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BOB-3 Specifications

[Bullet] Physical:

BOB-3 is designed in the 30-pin SIMM form factor, 3.50”(L) x 1.05”(W) x 0.35”(H). Module weight is about 12g (0.42oz). BOB-3 snaps into standard 30-pin SIMM sockets. Matching sockets are supplied with retail product, or sold separately to OEM customers.

[Bullet] Power Supply:

Nominal supply voltage range is +5VDC ±5% or +8~15V at 70mA typical. An auxiliary +5V regulated output (pin 3) is rated at 50mA and ±5% voltage tolerance. Auxiliary supply output current adds to main supply current drain, when main supply input (pin 1) is used.

[Bullet] Data Path:

The data path is asynchronous serial with crystal-controlled rates of 1200*, 2400, 4800, 9600, 19.2K, 38.4K, 76.8K*, and 153.6K* bits per second, using 8 data bits, no parity, one stop bit (8N1), inverted data, and 5V logic levels. BOB-3 connects directly to the TXD/RXD pins of most microcontrollers. An inverting RS-232 interface (industry standard) is required for connection to PC COM ports. Six of the BOB-3 module pins can serve as software-controlled digital outputs.

[Bullet] Video I/O:

RS-170A (NTSC) composite, 1Vpp 75 Ohm unbalanced input and output. PAL-B video compatibility is optional at ordering time. The video output contains a small (+1V) DC bias, which is common to many video sources and well-tolerated at the inputs to most video equipment. A color video background signal is automatically generated if video input is not supplied. Composite sync and character insertion control signals are optional on the digital output pins.

[Bullet] Character Format:

BOB-3 uses 12x13 pixel bitmaps. Up to 680 characters may be displayed, in 40 columns and 17 rows (16 if vertical scrolling is active). Hundreds of character patterns are provided, including upper & lower case, italics (small caps instead of italics in V4 firmware), European language support, and a set of graphics characters useful for bar graphs, boxes, etc. Non-ASCII characters and user-definable characters are accessible through a simple command protocol. Up to 63 custom characters may be loaded into font RAM by the user, replacing the default European and graphics characters. A BOB-3 Font Editor utility is supplied without charge to assist with custom character design (see links below).

[Bullet] Print Speed:

Printable characters 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 (e.g. 521uS per character at 19,200bps). 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 write cycles should be triggered from vertical sync and the print position should be near screen bottom. The crawl mode supplemental circuit given in the BOB-3 Application Guide (see below) is a vertical sync separator, and it’s often suitable for this purpose.

[Bullet] Character Display Options:

Only monochrome text is available in genlock/overlay mode. Characters from ROM are displayed by default in white with a thin black outline. Halftone (reduced video intensity) and black character backgrounds are optional. Characters from font RAM have less display flexibility. This includes European language support, which is part of the default RAM character set. Color display features, including character background control, are supported in local video generation mode. In local mode, blue matte background is supplied by default. Other background colors are available by command. Blinking may be selected for any character or group in either video mode. Manual adjustment of transparency as well as character and background brightness (gray scale) is optional, with external circuits. Vertical scrolling may be configured for any contiguous group of display rows. A single crawl (horizontal scroll) line* can display up to 256 characters sequentially. No other display is possible when crawl mode is invoked. The entire text display 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-3 and/or automatically generate a display at power-up time.

[Bullet] Notes:

* Denotes features added or revised in firmware version 3.

The start-up display (boot script) memory can be loaded with commands as well as printable characters, which allows BOB-3's operating modes to be semi-permanently configured for special applications. In some cases, this feature eliminates the need for a host computer or smart interface device. Read the Application Guide document for more details, or contact Decade Engineering to discuss your requirements.

Product specifications are subject to change without notice. Contact Decade Engineering to confirm current status if any specification is critical to your application.

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More BOB-3 Technical Information

BOB-3 V4 Application Guide (PDF, 400KB)  Version 4 firmware was phased in to BOB-3 production beginning in April of 2006. Version 4.0 migrates directly from version 3.5, but uses a new character ROM. The most significant difference is that italics are replaced with small caps. The new character ROM corrects a few character omissions and offers other useful enhancements.

BOB-3 V3 Application Guide (PDF, 400KB)  Everything we could think of to tell you about using BOB-3, and some things customers thought we should tell you, too! Thanks to all those who offered suggestions.

BOB-3 V2 Application Guide (PDF, 400KB)  Older firmware version; archived here for customer convenience.

BOB-3 Font Editor (EXE, 1.3MB)  For PCs only. Supports firmware versions 2, 3, and 4.

Default RAM Font (BFT)  For use with the BOB-3 Font Editor, in its native file format.

C Demo Program (ZIP)  Source code for a simple MS Visual C++ example program.

Linux Example (ZIP) A code fragment from the University of Michigan's Solar Car Team. Credit for this real-life BOB-3 application example goes to Robert Vogt IV, Strategy Director, 2005 UM Solar Car Team, Graduate Student, Computer Science and Engineering-AI.

BASIC Demo Program (TXT)  Source code for the QuickBASICtm example from the Application Guides.

RAM Character Codes (TXT)  An unformatted 'text' file containing all 63 character codes to make BOB-3 display the current RAM font. Can be transmitted to BOB-3 using the file transfer capability of a terminal emulator.

A Quick Test (TXT)  Another unformatted text file that you can send through HyperTerminaltm or equivalent. Provides a simple demonstration. Thanks to Donald McAfee PhD for this one and the next...

McAfee Astrometrics offers a complete description of an accurate timing data overlay system using BOB-3. Application source code is provided, for the popular BASCOM-AVR compiler.

Curtis Schreier developed Pygmy Forth code for a high-resolution horizontal bar graph display. BAR3.SCR is the Forth screen file. BAR3.TXT is plain ASCII. Curtis' email address is in the source code, and he's interested in corresponding with other BOB application developers.

Also see BOB-II application examples. Note that BOB-II application programs will require editing to work with BOB-3.

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Prices and Ordering Information