Introduction to PICAXE Microcontrollers

PICAXE MicrocontrollersAn Introduction by NearSys

What is a PICAXE?

• A family of microcontrollers• Based on the PIC microcontroller• Internally programmed with an interpreter and

communications program• Program stored in the PIC’s internal EEPROM• Interpreter operates on one instruction at a time

PICAXE Variations

PICAXE-08M2

PICAXE-14M2

PICAXE-18M2

PICAXE-20M2

PICAXE-28X2

PICAXE-40X2

PICAXE Voltages

Five volt chips, but can operate at 1.8 volts

PICAXE Multiple Programs

PICAXE-08M2

PICAXE-14M2

PICAXE-18M2

PICAXE-20M2

PICAXE-28X2

PICAXE-40X2

PICAXE Multiple Programs

PICAXE-08M2

PICAXE-14M2

PICAXE-18M2

PICAXE-20M2

PICAXE-28X2

PICAXE-40X2

PICAXE Clock Speed

PICAXE-08M2

PICAXE-14M2

PICAXE-18M2

PICAXE-20M2

PICAXE-28X2

PICAXE-40X2

PICAXE Clock Speed

PICAXE-08M2

PICAXE-14M2

PICAXE-18M2

PICAXE-20M2

PICAXE-28X2

PICAXE-40X2

PICAXE Pins

• Logic low < 1.4 V

• Up to four banks, A, B, C, and D depending on variation

• Most I/O pins are bidirectional

• Hardware interrupts on the X2

• Software interrupts on both the M2 and X2

PICAXE Memory

• Program

• RAM

• Data

• Scratch Pad

PICAXE Memory

• Program

• RAM

• Data

• Scratch Pad

PICAXE Memory

• Program

• RAM (variables)

• Data

• Scratch Pad

PICAXE Memory

• Program

• RAM

• Data

• Scratch Pad

PICAXE Memory

• Program

• RAM (variables)

• Data

• Scratch Pad

Code ExamplesInput Commands

• PIN

• COUNT

• PULSIN

• SERIN

• READI2C

• READADC and READADC10

• IRIN

• RFIN

Code ExamplesOutput Commands

• HIGH and LOW• PULSOUT• SEROUT• WRITEI2C• PLAY and TUNE• SERVO• PMWOUT• IROUT• RFOUT

Code ExamplesProgram Flow Control Commands

• GOTO• GOSUB-RETURN• FOR-NEXT• DO-LOOP (UNTIL or WHILE)• IF-THEN-ELSEIF• ON-GOTO (GOSUB)• SELECT-CASE• BRANCH

Code ExamplesCommunications Commands

• I2cslave 10100000,i2cfast,i2cword

• writei2c 0,("hello")

• readi2c 0,(b0,b1,b2,b3,b4)

Code ExamplesCommunications Commands

• debug

• serout B.0, T1200_4,(“Testing”)

• serin C.1, T1200_4,(“X”),B.0, B.1, B.2

• sertxd (“Value: ,”B.5)

• serrxd (B.0, B.1, B.2, B.3)

• hsersetup b9600_4, %10

• hserout 0,(b.0)

• hserin 0,50

Code ExamplesMemory Commands

• PEEK-POKE

• READ-WRITE

• GET-PUT

The Editor

EditorSelecting the Mode

EditorSelecting the Serial Port

EditorExample of a Text Program

EditorExample of a Flowchart Program

EditorExample of a Wizard

EditorExample of Syntax Check

EditorDownloading Program

EditorSimulating a Program

EditorDebugging a Program

EditorTerminal Program

Want to Learn More?

Boise Robotics Group (The BoRG)

Third Saturday of the Month

Hobby Town at Cole and Ustick

10:00 AM to noon

Learn to Make a Robot

A community education class

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