The Workbench

After over 35 years of development and helping other designers and engineers, The Workbench site will be closing due to age and retirement of members. Sales of certain items in stock will continue until depleted. The basic site will remain open for some time for item documentation. If you have any special request please email.

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If you stumbled here by accident or came intentionally - Welcome to the Workbench! A place started by  a couple of micro controller enthusiasts. As you click your way around you may find some useful software utilities or information. Most of the boards and designs are results of engineers helping each other during development of projects. As needs change so do the projects and adapters. Below are the current boards. Previous projects are slowly moved to the archived section.

RS232 Custom Serial Adapters

Serial I/O RS232 Adapters

A small RS232 adapter using a Max233. Use for connecting microcontrollers to PCs or other terminals. Schematic and PCB (kit or bare)  available.

Two models AD233AK (on left) without handshake lines and AD233BK (layout on the right) which includes CTS/RTS handshake via the Max233 pinouts from the DB9 connector. Requires assembly


Super Small Serial RS232 Adapters

AD233BK layout


A232DB shown assembled

Tiny pcb approx 0.61 x 0.53 inches! Ideal for those projects that require an affordable RS232 I/O port. The kit Includes an SOIC Max232 , four 1uf SMD capacitors, pcb and a DB9F connector. It accepts any TTL RS232 Rx/Tx signals. Requires 5volts DC. This pcb was originally designed for a custom DB9 shell which was a couple of mm larger than most DB9 hoods found in electronic stores. One could most probably make it fit in a standard hood by shaving the corners and edges. A232DBH is also available as a LVTTL  3v version, A232DBH3, which uses an IC3232 transceiver and 0.1uf caps

A232DB 5v ver shown in DB9 hood also available in a 3 volt version

More info..


New! A232DBCT same as the above but it includes the CTS/RTS lines. Available as a 5v module ( A232DBHCT ) or a LVTTL 3.3v module (A232DBHCT3V). The modules include a plastic DB9 hood kit. Pinouts on the board are V+,GND,CTS,RTS, TX and RX

A232DBCT (5v or 3.3v)

More info.....

Available as a kit or assembled


ST232SA  3.3v TTL to RS232 adapter module has a 3.5MM stereo jack which provides three lines, Gnd,Tx and Rx. The board provides jumpers to configure the jack’s Tip and Ring as Tx or Rx. It comes as assembled or as a kit. Will work on 3.3v to 5v....more info.

RJ45SA  3.3v TTL to RS232 adapter with an RJ45 jack. It provides connections for Tx,Rx,Cts and Rts. The pin connections on the RJ45 are Lantronix compatible. It comes as assembled or as a kit. It will work on 3.3v to 5v....more info.


A232DTE  3.3v TTL to RS232 adapter configured as a DTE adapter with a male DB9 connector. It comes as assembled or as a kit. It will work on 3.3v to 5v.


More info....


A232DBL  3.3v or 5v  Dual TTL to RS232 adapter board. Designed for engineers/hobbyists who need an adapter without a DB9 connector so that they can wire their own. The board provides two separate TTL to RS232 I/O channels, each has Tx and Rx lines. The adapter is available as a kit or assembled....more info.


RS232 boards which run on 7 to 14 vdc power supplies

AD231_12V An RS232 adapter with an on-board voltage regulator, protection diode and an LED indicator. The adapter can be configured with or without  CTS/RTS handshake lines. It will run off a 7 to 14 vdc power supply and can provide a -12v to +12v RS232 line signal. More info...


AD233_12V An RS232 adapter with an on-board voltage regulator, protection diode and an LED indicator. The adapter can be configured with or without  CTS/RTS handshake lines. It will run off a 7 to 14 vdc power supply and provides a -10v to +10v RS232 line signal.More info...

Dual RS232 Adapter

3 - 5v supply

AD233DK (on left) Similar to the AD233AK except that it has a second I/O port. Designed for microcontroller  projects that require two RS232 I/Os. For example one port can be used to collect data from a device such as a GPS and the other port can be connected to a PC terminal to monitor or control the device. Uses a Max233,or equiv, IC (included) and requires a 3 to 5v dc supply.Requires assembly

RS232 (A)

RS232 (B)


TTL  (A) RX-TX   (B) RX-TX

AD232Q four port serial RS232 adapter

For those projects that require multiple serial RS232 I/O ports. Features a very small adapter with four independent serial RS232 ports (DB9 female connectors). The adapter can can be powered by an on-board 5v regulator or by the host’s 5v supply (jumper selectable). All I/O pins, including the power lines, are brought to a 5x2 standard 0.1” spaced header. The kit mainly comprises of  surface mount parts, such as the two IC232s, capacitors and resistor.Requires assembly More.....

AD232Q shown assembled

RS232 adapter with an on-board regulator which can, if possible,  use the DTE ‘s (such as a PC) RTS/DTR  voltage to power the Max232 IC. The RTS/DTR lines are protected with fast switching diodes. An external power supply can be used if the DTE device cannot provide sufficient power on the RTS/DTR lines. Jumper selectable. Pinouts for CTS,RX,TX, GND , plus for an external supply, if required. Includes an LED to indicate power supply. The kit mainly consists of surface mount parts. Requires assembly More......

A small RS232 adapter with handshaking options. Jumper configurable. Can be configured as a null modem with no handshking, or with DSR/DTR handshaking or with CTS/RTS handshaking. It provides Rx/Tx pins and 2 control pins for either DSR/DTR or CTS/RTS handshake signals. The kit uses all surface mount parts and requires assembly. The IC is a Max232 SOIC16. The board has a power LED indicator and requires 5v for operation. It has a standard DB9 female RS232 connector. Requires assemblyMore....

FTDI 232R Board


The UFT232R A USB to TTL RS232 kit. it is based on the new FT232R chip by FTDI. The new chip reduces the components required and yet provides all of the extended functionality. Available with a Type A or Type B USB connector. More info..

UFT323R USB to TTL RS232 kit shown assembled


A small USB board based on FTDI’s FT232BM chip. Allows microcontroller TTL serial I/O via an RS232 USB connection. Ideal for a microcontroller project TTL to RS232 via a USB connection to a PC. Requires assembly


Mini Power Supplies

Mini Power Supplies for breadboards 5v, 3.3v and dual voltage modules for quick prototyping and projects. Standard .1” pins easily connects to pcbs and development boards.

PSU5-3 kit

The tiny PSU5-3A provides a 5v dc source using an LM7805 and PSU5-3B provides 3.3v using an LM2937. Includes a power LED. Input 7-15v DC via a 2.1mm power socket.

PSU3 Pcb Layout

PSU35 kit

Dual Supply!3.3v as well as 5v supply. This versatile little supply includes a bridge so that 7-15v AC or DC can be used as the source, each output has its own power LED. Standard 2.1mm power socket. Includes an LM7805 and an LM2973

PSU3-5 Pcb Layout

PAST PROJECTS: Some parts/kits are still available.
If you are interested please email.

Graphic LCD stuff....

Seiko-Epson SED1330, Samsung KS0108 and Toshiba T6963C based displays.

The T6963C and SED1330 adapter for LCD displays up to 256x128 pixels. It provides the negative -15v for the display bias. Straight 18 pin as well as a 2x10 pin headers to accommodate most displays. It connects directly to the GLiPIC controller.

Sed1330 based large 256x128 Graphic LCD which can be used with the GLiPIC board!

KS0108 based 128x64 LCD. Image created using GLiPIC software

Toshiba T6963C controller based 240x64 display

Workbench PIC based development boards &  adapters

Unlike the venerable HD44780 based character LCD, graphic LCDs do not have any ad-hoc standard. Small graphic LCDs come in many different flavors, configurations and sizes. Some have on-board dedicated graphic controller chips and some do not. All graphic LCDs require a negative voltage to drive the displays contrast. The amount varies with the physical size of the display. Usually, 240x64, and less, require -10v, 256x128 need -15v and larger displays may require up to -24v. To further complicate matters, this required negative voltage is usually not provided by the LCD itself. This means additional circuitry.  To drive an LCD without an on-board graphic controller with an 8 bit micro would be daunting, indeed, and is beyond the scope of the Workbench boards. All of the COMPSys Workbench development boards rely on LCDs with controllers. This usually requires 12-16 pins of the micro, and leaves the rest of the micro’s pins for the user to implement for other uses such as I/O, analog readings, buttons, keypads etc. Some graphic LCDs even have a serial interface requiring only a handful of connections. Three of the popular controllers for small size displays are the Seiko-Epson SED1330, Samsung KS0108 (akin to the Hitachi HD61202), and the Toshiba T6963C. Most of the LCDs that use these controllers have an 8 bit data bus along with 4 to 6 control lines. The Workbench controllers are configured to work with most of the above controllers. Since pin arrangements vary from one manufacturer to another, adapters become a necessity. All of the LCDs mentioned here a 1 bit color displays (black/white) and are not capable of grayscale shades.

The original  GLiPIC controller

Designed for use with KS0108 Graphic LCD controllers, however it can be used as a general purpose controller. Plus, with the available adapters it can be used with other LCD displays such as those that have a T6963C or SED1330 controller. The adapters provide the correct pinouts as well as the negative voltage for the displays. The GLiPIC board houses a 20MHz 16F877, Max232, 24LC256 I2C eeprom and an LM7805 regulator.

GLADPS2 adapter which allows use with some T6963C and SED1330 based LCDs. It provides up to -10v Vee

GLI2 - The new GL series 20Mhz controller board. Same compact size as the original GLI board but has an on-board -15v power supply to drive LCD panels up to 256x128 in  size. Low cost adapters available for most of the popular graphic controller LCD displays, such as the SED1330, T6963C, KS0108, and the HD61202. Uses a PIC16F877 mcu, Max232 serial  transceiver, 24LC256 I2C eeprom, a Max637 voltage booster and an LM7805 voltage regulator. The controller’s PORTA and PORTB pins are available for other uses and are brought to pin outs for  easy connections. Requires 7-20v DC power supply.

  • On board serial I/O via a DB9 connector CTS/RTS lines can be used for hardware handshaking
  • 5 different LCD adapters to choose from..with more in development
  • On-Board 32kb eerpom storage for images.
  • Built-in negative voltage supply to drive LCD panels
  • Can be programmed serially with a bootloader.
  • 5 volt regulator
  • Can be used with the new PIC18F452 controller for added programming space.
  • With minor chanages in pin assignments it can run the same firmware as the original GLiPIC board.

The kit requires soldering a few surface mount components.

Click here for more info about the board and the adapters.

GLI2 Controller is supplied with one LCD adapter (5 adapters to choose from) Requires assembly


A small development kit which connects to an Optrex 51320 COG (chip on glass) graphic LCD. The dot matrix LCD has an LED backlight (5v). The board includes a 28 pin DIP PIC16F876 with 8k code space (many other 28 pin PICs can be used if more programming space is required). There is an on-board 5v power regulator as well as an RS232 IC (Max232 or equiv). It also has provisions for an optional I2C eeeprom and pull up resistors. Unused pins, such as PortA, are available via pin headers. The PIC’s programming pins are brought to a header so that the PIC can be programmed using a conventional PIC programmer. An alternative, method is to load the PIC with a bootloader and then program it via the board’s serial DB9 connector. Sample PICBasicPro code is available in the Workbench Support section. The kit is available with or without the LCD.

COG30LCDK (kit requires soldering)


A small (1.25"x2.5") LCD interface development board specifically designed for T6963C based LCD's with 2x10 headers for LCDs such as the Optrex DMF5005, Sharp LM24014, Solomon LM6270, Sanyo DG0572 etc. This board makes it very easy for developers to experiment with graphic LCDs since it can mount directly to the LCD via its 2x10 female header. The board includes a PIC microcontroller, an  RS232 interface IC, a 256kb Eeprom for storage and a -15v  variable negative voltage supply for the LCD's display panel. It alsoincludes a 5v regulator.Soldering required. More info...

MMC/SD and DataFlash development boards



Complete kits for MMC and SD cards  Available

Board using a PIC16F876, an eeprom, and a MAX233. Standard DIP sockets. PCB Model MMC3B can use either an 8 pin DIP or a SOP-8 for the eeprom, making it possible to use FRAMs such as the FR24CL64 3.3v I2C memory from Ramtron, Inc.On the right MMSD3F kit for SD as well as MMC cards.Requires assembly

Source code written in PBP V2.47 available. This allows one to read/write to a single file on a FAT16 formatted MMC.

Ideal for long term data logging by providing large storage space.


Similar to the MMSD3 board but much more compact. It is a PIC based 3.3v development board that is interfaced to a SD/MMC socket. Serial I/O is available via a standard DB8F RS232 connector. The PIC can be loaded with a bootloader so that it can be programmed serially without having to remove it from the board. It also includes a 5 pin header for programming the PIC with a conventional programmer. The SPI lines from the MMC/SD are connected to the hardware SPI pins on the 16F876 / 18F252 PIC as are the serial RS232 lines. It includes a Ramtron 64kbit FRAM, a Max3232 (or equiv.), SD/MMC socket, a 3.3v LDO regulator, a PIC 16F876 or 18F252 and associated passive components.Requires a 7-16v DC supply. PICBasicPro demo code available. PIC program  for a ‘single file’ system on a  FAT16 formatted card also available, which allows the card to be read on a Windows PC card reader. Works with SD as well as MMC cards. Ideal for long term data logging, where the data is received at a slow I/O rate. Requires assembly


MMC & SD card prototyping kits

MMSD9Ka socket pcb for the SecureDigital (SD) card. The kit includes the pcb and SD socket. Requires assembly

Shown assembled (SD card not included)


A small carrier board for the Ethernet 10/100 base XPort webserver module (by Lantronix Inc). The board includes a 3.3v regulator, a Max3232 RS232 transceiver, and has provisions for using the modules three control pins. More information and software for the XPort module visit the Lantronix website. More info...

XP02 carrier board shown with a Lantronix XPort(tm) module installed (module not included)

Handy, small, versatile general purpose controller boards for 28 Pin PIC microcontroller. Perfect for quick projects, robotics or use as a handy bench tool. Includes two eeproms (for data storage).

Tiny footprint can fit small project enclosures. With a bootloader, the PIC can be programmed serially.


  • On-board regulator and power LED
  • On-board  RS232 driver chip
  • All PIC pins are brought to headers
  • CB28A has room for 2 I2C eeproms
  • Reset button
  • Selectable power, on-board/external
  • Small and economical

The BOTB2 board was designed for a robotics project that required controlling servos and a variety of sensors.The board can use a 16F876 or 18F252 PIC. Headers are provided for power as well as the PIC’s pins. It has provisions for an RTC (DS1307) clock, a Max232 SOIC, an I2C 24CL256 eeprom, on-board power regulator, power LED, a programming header and several jumpers to enable/disable on-board or external power for devices.


Connector for 20 contact Flat Flex ribbon

20 contact and carrier pcb for TAB/COG LCDs which have a 0.5mm pitch 20 contact Flat Flex ribbon cable. The carrier can fit in a standard 0.6” wide  20 pin IC socket

20 contact Flat Flex connector and carrier pcb kit #COG128 (requires soldering)

Right: Shown assembled and connected to a 128x64 Graphic LCD (LCD not supplied)

Email if you require an 18 or 30 pin adapter

Shown assembled

A232P88 dev board kit

On the right, the A232P88 compact controller board which includes a PIC16F88, a Max3232 IC, and voltage regulator. It can be powered externally or can draw its power from the PC’s serial lines. The PIC can be programmed via a 5 pin header.Ideal for small sensor projects.

More info.....


PCB Layout

SOIC8 to DIP8 Carrier

Useful tiny carrier! Use existing DIP8 sockets to try out new SOIC8 devices such as a FRAM to replace a standard eeprom. Available in the parts section

Shown with a FRAM mounted


Rayson BTM-182 Bluetooth RS232 module carrier board for 3.3v and 5v projects. The carrier boards provide TTL serial I/O lines (Tx,Rx,CTS and RTS) and can serially communicate with most Class 2 Bluetooth devices. More info.....

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Updated on:

February 16, 2018 

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