BS2 programming board (board of education)

Build your own low cost Basic Stamp II board of education by parallax. The "trick" here is to buy the OEM version of Basic Stamp 2 from parallax (Basic Stamp 2 interpreter chip DIP). This will keep the cost very low but there's a catch. You must be able to solder electronic components on a Veroboard (StripBoard).

Details

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You can buy a complete programming board for basic stamp 2 from parallax (www.parallax.com), but the cost is little bit high especially if you don't live in United States.

In this article we will create our board from common and cheap electronic components. The only thing you have to buy from parallax is Basic Stamp 2 interpreter chip (DIP). The cost of this chip is about 17$ (at least at the time this article was written). So you save more than 50$.

Components

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• One basic Stamp 2 interpreter chip (DIP).
• One 20MHz piezoelectric crystal.
• One 24C16 memory chip (I2C).
• Two 1000μF electrolytic capacitors (16 Volts).
• Four 4.7KΩ resistors (1/4 Watt).
• Eight 10KΩ resistors (1/4 Watt).
• Two 1nF capacitors.
• Two 100nF capacitors.
• Two BC547 npn transistros.
• One BC557 pnp transistor.
• One LM2940 LDO voltage regulator (with the appropriate cooler, if you plan to drag more than 500mA).
• One green common LED.
• One ALPS button (a digital push button. Not switch) for a manual reset feature.
• One power jack.
• Two single row female pin headers (one with 16 pins and one with 13. If you have headers with more pins, just cut them).
• One female double row pin header with 20 pins totally (If you have a header with more pins, just cut it).
• One small breadboard (optional).
• A female 9 pin DSUB connector (for PCB).
• A 28 pin DIP socket (for the microcontroller).
• A 8 pin DIP socket (for the memory chip).
• A Veroboard - StripBoard (or a PCB but I don't include a layout. Make your own).
• Wire for connections
• Solder and soldering iron

Also you will need a stabilized 12V, 9 Volt or even a 6Volt external power supply, due to the low dropout voltage regulator (a 9Volt alkaline battery will do just fine).

Schematic Diagram

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Here is the schematic diagram of the BS2 programming board (click on the picture to enlarge).

Attention: Even if this is not shown on the schematic, it's very wise to place a 100nF capacitor near the power pins (pin 2 and 4) of PIC16C57C IC (with the emended basic stamp 2 interpreter). This will improve the power's supply behavior when you use medium or high frequency pulses (or other signals).

 

Pictures

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In the following picture you see the completed board. I didn't use the optional breadboard. Also I used a switch and a 9Volt battery holder instead of a power jack. The two male pin headers with 90^o angle (3 pins each) are there in order to connect standard RC servos.

And here is a interesting use of the board. For this small robot I used two continuous rotation servos from parallax