PICAXE is a microcontroller system based on a range of

Microchip An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...

PIC PIC or pic may refer to: Places * Penbay International Circuit, or PIC, a motor track circuit in Pingtung County, Taiwan * Pic River, in Ontario, Canada * Picayune (Amtrak station) (Amtrak station code PIC), Mississippi, United States * Pic, a ...

microcontroller A microcontroller (MC, uC, or μC) or microcontroller unit (MCU) is a small computer on a single integrated circuit. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable input/output peripherals. Pro ...

s. PICAXE devices are Microchip PIC devices with pre-programmed firmware that enables bootloading of code directly from a PC, simplifying hobbyist embedded development (not unlike the

Arduino Arduino () is an Italian open-source hardware and open-source software, software company, project, and user community that designs and manufactures single-board microcontrollers and microcontroller kits for building digital devices. Its hardwar ...

and

Parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different sightline, lines of sight and is measured by the angle or half-angle of inclination between those two lines. Due to perspective (graphica ...

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 popular with electronics hobbyists since the early 1990s. Technical specifications Although ...

systems). PICAXE devices have been produced by Revolution Education (Rev-Ed) since 1999.

Hardware

There are currently six (6) PICAXE variants of differing pin counts (8-14-18-20-28-40) and are available as DIL and SMD. PICAXE microcontrollers are pre-programmed with an

interpreter Interpreting is translation from a spoken or signed language into another language, usually in real time to facilitate live communication. It is distinguished from the translation of a written text, which can be more deliberative and make use o ...

similar to the

but using internal EEPROM instead, thus reducing cost. This also allows downloads to be made with a simple serial connection which eliminates the need for a PIC programmer. PICAXE is programmed using an RS-232 serial cable or a USB cable which connects a

computer A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

to the download circuit, which normally uses a 3.5 mm jack and two

resistors A resistor is a passive two-terminal electronic component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active e ...

Programming language

PICAXE microcontrollers are programmed using

BASIC Basic or BASIC may refer to: Science and technology * BASIC, a computer programming language * Basic (chemistry), having the properties of a base * Basic access authentication, in HTTP Entertainment * Basic (film), ''Basic'' (film), a 2003 film ...

. The PICAXE interpreter features bit-banged communications: * Serial (asynchronous serial) * SPI (synchronous serial) *

Infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

(using a 38 kHz carrier, seven data bits and five ID bits) * One-wire The "readtemp" command reads the temperature from a DS18B20 temperature

sensor A sensor is often defined as a device that receives and responds to a signal or stimulus. The stimulus is the quantity, property, or condition that is sensed and converted into electrical signal. In the broadest definition, a sensor is a devi ...

and converts it into

Celsius The degree Celsius is the unit of temperature on the Celsius temperature scale "Celsius temperature scale, also called centigrade temperature scale, scale based on 0 ° for the melting point of water and 100 ° for the boiling point ...

. All current PICAXEs have commands for using hardware features of the underlying PIC microcontrollers: * Hardware asynchronous serial * Hardware synchronous serial * Hardware PWM * DAC * ADC *

SR Latch In electronics, flip-flops and latches are circuits that have two stable states that can store state information – a bistable multivibrator. The circuit can be made to change state by signals applied to one or more control inputs and will ou ...

* Timers (two on X2/X1 parts which have settable intervals, only one on M2 parts with a fixed interval, older parts have none) *

Comparator In electronics, a comparator is a device that compares two voltages or currents and outputs a digital signal indicating which is larger. It has two analog input terminals V_+ and V_- and one binary digital output V_\text. The output is ideally ...

s * Internal temperature measurement

Program space

All current PICAXE chips have at least 2048 bytes of on board program memory available for user programs: * 08M2 - 2048

byte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable un ...

s * 14M2 - 2048 * 18M2+ - 2048 * 20M2 - 2048 * 20X2 - 4096 * 28X1 - 4096 * 40X1 - 4096 * 28X2 - 4096 per slot with four slots for a total of 16 KiB * 40X2 - 4096 per slot with four slots for a total of 16 KiB

Clock speeds

The default clock speed for all M2 and X1 parts is 4 MHz and for the X2 parts is 8 MHz. The SETFREQ command allows speeds from 31 kHz up to 8 MHz for X1 parts, 31 kHz up to 32 MHz for M2 parts and 31 kHz up to 16 MHz for X2 parts (up to 64 MHz for the 20X2) using the internal resonator. An external resonator can be used with the X1 parts for from 4 MHz to 20 MHz clock speeds and with the X2 parts for 16 MHz to 64 MHz clock speeds.

Project boards

Project boards for different applications are sold by Rev-Ed which contain the PICAXE, download circuit and may also contain a prototyping area or high power output drivers.

Software

Revolution Education develop software for writing programs for PICAXE.

PICAXE Programming Editor

PICAXE Programming Editor is a

Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

-only IDE for writing PICAXE programs in BASIC code or a simple flowchart. PICAXE Programming Editor features: * source code colour

syntax highlighting Syntax highlighting is a feature of text editors that is used for programming language, programming, scripting language, scripting, or markup language, markup languages, such as HTML. The feature displays text, especially source code, in differe ...

* auto indentation * syntax check and program download * code explorer to shown variable, label and constant values * full on screen simulation with animated chips and line by line code highlighting * simulation breakpoints by line number and variable value * debug and serial terminal windows * AXE027 download cable testing and port identification tools * various testing tools such as the analogue calibration wizard * various code generation wizards (pwmout, tune, RTC setting, etc.)

AXEpad

AXEpad is a cross-platform application recommended for

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

and

Mac Mac or MAC may refer to: Common meanings * Mac (computer), a line of personal computers made by Apple Inc. * Mackintosh, a raincoat made of rubberized cloth * Mac, a prefix to surnames derived from Gaelic languages * McIntosh (apple), a Canadi ...

users. It lacks some of Programming Editor's wizards, simulation and MDI.

Logicator for PICAXE

Logicator is an easy to use

shareware Shareware is a type of proprietary software that is initially shared by the owner for trial use at little or no cost. Often the software has limited functionality or incomplete documentation until the user sends payment to the software developer. ...

flowcharting program. The Logicator web page is out of date as the free version does support all commands but shows nag screens. PICAXE Programming Editor 6, the successor to PICAXE Programming Editor 5, has Logicator flowcharting merged into it so separate Logicator software is no longer required. Like PICAXE Programming Editor 5, PICAXE Programming Editor 6 is freeware.

Third-party software

Yenka

Yenka is a program developed by Crocodile Clips Ltd which has flowcharts and simulation.

Others

Many companies and organizations have put out their own editors with special features. Some include language translators or serial connectors, so there is a wide variety of consoles to be used.

Support

Support is available at the Technical Support section of the PICAXE website and at the PICAXE Forum. The PICAXE Forum has a finished projects section where completed projects and PICAXE programs are posted, plus there is a similar section on the PICAXE website.

References

External links

Official PICAXE WebsiteBASIC commandsDistributors - PICAXEIntroducing the PICAXE SystemSnap Electronics educational system using PICAXE
{{DEFAULTSORT:Picaxe Microcontrollers Microchip Technology hardware