BASIC Stamp

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BASIC Stamp

The BASIC Stamp is a microcontroller with a small, specialized BASIC interpreter (PBASIC) built into ROM. It is made by Parallax, Inc. and has been quite popular with electronics hobbyists since the early 1990s due to its low threshold of learning and ease of use (due to its simple BASIC language).

Although the BASIC Stamp has the form of a DIP chip, it is in fact a small Printed Circuit Board that contains the essential elements of a microprocessor system:

A Microcontroller containing the CPU, a built in ROM containing the BASIC interpreter, and various peripherals
Memory (a serial EEPROM)
A clock
A power supply
External input and output

PBASIC, the BASIC Stamp language, incorporates common microcontroller functions, including PWM, serial communications, I²C and 1-Wire communications, communications with common LCD driver circuits, hobby servo pulse trains, pseudo-sine wave frequencies, and the ability to time an RC circuit which may be used to detect an analog value.

The end result is that a hobbyist can connect a 9V battery to a BASIC Stamp and have a complete system. A connection to a PC allows the programmer to download software to the BASIC Stamp, which is stored in the onboard memory device. This memory stays programmed until it is erased and reprogrammed (the memory remains intact even when the power is removed).

There are currently four variants of the interpreter, BASIC Stamp 1, BASIC Stamp 2, the Javelin Stamp and the Spin Stamp. The Basic Stamp 2 variant has seven sub-variants:

BS1
BS2
BS2e
BS2sx
BS2p24
BS2p40
BS2pe
BS2px

These sub-variants feature more memory, faster execution speed, additional specialized PBASIC commands, extra I/O pins, etc, in comparison to the original BS2 model. While the BS1 and BS2 use a PIC, the remaining BASIC Stamp 2 variants use an SX processor.

The third variant is the Javelin Stamp. This module uses Sun Microsystem's Java programming language instead of Parallax's PBASIC.

The fourth variant is the Spin Stamp. The module is based on the Parallax Propeller and therefore uses the SPIN programming language instead of PBASIC.

Many companies now make virtual "clones" of the BASIC Stamp with additional features, such as faster execution, Analog-to-digital converters and hardware based PWM which can run in the background. However, many use the same pin out as the BASIC Stamp, to allow BASIC Stamp users to plug in their products in a design that already uses the BASIC Stamp.