(Last Updated Jan 25, '06)
Figure #1.
Figure #2.
The Basic Stamp 2 (BS2-IC) is packaged in a convenient 24-terminal package and is uniformly priced at about $49.00. The user will then need some type of carrier board and a source of power, including +5 VDC for powering peripherals.
This "Homebrew" design uses "through whole" integrated circuits to implement the Stamp. This includes a 28-terminal Parallax Basic Interpretter, m 8-terminal 24LC16B EEPROM and a 16-terminal MAX232 RS232 interface. In addition, the design provides a well regulated source of +5 VDC using a 7805 regulator, power on LED, a reset pushbutton and a good sized protoboard.
Note that this circuit perfroms exactly as a Parallax Basic Stamp 2. Simply download the editor software from the Parallax site and you are in business.
With the BS2-IC, the functional IO designations "P0" through "P15" are on physical terminals 5 though 20 of the 24-pin DIP. With this design "P0" through "P15" are on terminals 10 through 25 of the 28-terminal interpretter.
Each of the interpretter terminals are brought out to a dedicated pad and the IO designations are silkscreened on the board.
This design uses a 9-term DB9 RS232 interface. Use a standard M to F cable with all nine leads wired through. If you do not have a conventional serial connector, get a USB to RS232 adaptor.
The dimensions of the board are 4.0 X 3.19 X 0.062 inches. Four holes are provided which will accommodate #4 screws
The plated holes are on a 0.1 inch grid.
+5 VDC and GRD busses are provided. In the photo of the bottom of the board, the +5 VDC is available on the horizontal extending across the top and ground on the lowest horizontal.
The power requirement is 7 - 15 VDC at 100 mA. The connector is 2.1 mm ID X 5.5 mm OD, female, with the center positive.
Working with the Unit
Permanent.
Although this is a different board, it does provide an example of how one might use the unit for permanent or semipermanent applications. The terminal blocks are Digikey ED2601 and the standoffs are Digikey 1902CK 0.5 inch nylon spacers with #4-40 threads. I use Digikey CD2003 24 awg solid hookup wire, but you can use whatever seems best for your application and budget.
Experimental.
The photo which appears below illustrates how the Homebrew may be interfaced with a solderless breadboard. Note that I have soldered header connectors on P0 through P4 on one side, P5 through P15 on the other and on +5 VDC and GRD. The interfacing breadboard is an 830 tie point board. The header connectors soldered on the board are Digikey 929974-01-16. Note that one must be cut into two pieces consisting of 5 and 11 holes and a two pieces of four holes cut from another piece.
These connectors do hide the silk screen IO silkscreen, but it is easy enough to remember that Px is on terminal x + 10. That is "P0" is on terminal 10, "P1" on terminal 11, etc.
I have found the 22 awg solid wire interface well with these connectors and with the breadboard.
In my mind, this arrangement offers a whole lot more than the Parallax Board of Education at a fraction of the price.
Figure #3.
Discontinued
(Last Updated Jan 25, '06)
Figure #1.
Figure #2.
The Basic Stamp 2 (BS2-IC) is packaged in a convenient 24-terminal package and is uniformly priced at about $49.00. The user will then need some type of carrier board and a source of power, including +5 VDC for powering peripherals.
This "Homebrew" design uses "through whole" integrated circuits to implement the Stamp. This includes a 28-terminal Parallax Basic Interpretter, m 8-terminal 24LC16B EEPROM and a 16-terminal MAX232 RS232 interface. In addition, the design provides a well regulated source of +5 VDC using a 7805 regulator, power on LED, a reset pushbutton and a good sized protoboard.
Note that this circuit perfroms exactly as a Parallax Basic Stamp 2. Simply download the editor software from the Parallax site and you are in business.
With the BS2-IC, the functional IO designations "P0" through "P15" are on physical terminals 5 though 20 of the 24-pin DIP. With this design "P0" through "P15" are on terminals 10 through 25 of the 28-terminal interpretter.
Each of the interpretter terminals are brought out to a dedicated pad and the IO designations are silkscreened on the board.
This design uses a 9-term DB9 RS232 interface. Use a standard M to F cable with all nine leads wired through. If you do not have a conventional serial connector, get a USB to RS232 adaptor.
The dimensions of the board are 4.0 X 3.19 X 0.062 inches. Four holes are provided which will accommodate #4 screws
The plated holes are on a 0.1 inch grid.
+5 VDC and GRD busses are provided. In the photo of the bottom of the board, the +5 VDC is available on the horizontal extending across the top and ground on the lowest horizontal.
The power requirement is 7 - 15 VDC at 100 mA. The connector is 2.1 mm ID X 5.5 mm OD, female, with the center positive.
Working with the Unit
Permanent.
Although this is a different board, it does provide an example of how one might use the unit for permanent or semipermanent applications. The terminal blocks are Digikey ED2601 and the standoffs are Digikey 1902CK 0.5 inch nylon spacers with #4-40 threads. I use Digikey CD2003 24 awg solid hookup wire, but you can use whatever seems best for your application and budget.
Experimental.
The photo which appears below illustrates how the Homebrew may be interfaced with a solderless breadboard. Note that I have soldered header connectors on P0 through P4 on one side, P5 through P15 on the other and on +5 VDC and GRD. The interfacing breadboard is an 830 tie point board. The header connectors soldered on the board are Digikey 929974-01-16. Note that one must be cut into two pieces consisting of 5 and 11 holes and a two pieces of four holes cut from another piece.
These connectors do hide the silk screen IO silkscreen, but it is easy enough to remember that Px is on terminal x + 10. That is "P0" is on terminal 10, "P1" on terminal 11, etc.
I have found the 22 awg solid wire interface well with these connectors and with the breadboard.
In my mind, this arrangement offers a whole lot more than the Parallax Board of Education at a fraction of the price.
Figure #3.
Discontinued