Miskatino Basic

This project was created to simplify teaching electronics in the school. It is a simple implementation of BASIC programming language to control Arduino Mini (2k) or STM32F103 microcontrollers. It is exposed via serial interface (e.g. UART) and so MCU could be programmed either from computer or smartphone with the help of bluetooth module. Now you can try it in web-emulator also!

Demo videos - on programming with smartphone and on using web-emulator:

Supported MCUs

The target hardware is really 32-bit ARM controllers, preferably STM32F103, which are cheaper than 8-bit Arduinos, but provide over 10 times more memory and 5 (or 10 with quartz) times faster execution, along with 32-bit integers instead of 16-bit. In future the project is supposed to be extended to cover LPC13xx and LPC21xx chips of NXP and probably Raspberry Pi.

• Arduino Mini 2k - 700 bytes for code, 300 for variables (also Arduino Micro / Leonardo / Duemilanove etc.)
• STM32F103 - code and data could take up to 20 kBytes, 32-bit variables, 100000 lines per second (work in progress)

Setup

Build the project, upload firmware. Set your communication line (either Bluetooth UART module or USB-UART bridge, like FTDI) to 115200 baud (or change the speed in the code before building). Plug in, press reset - you should see some greeting like Miskatino v1.0.

Alternatively there is web-emulator where anyone can play with the project on virtual Arduino Nano board with LEDs, switches and potentiometer.

Recognized commands and functions

(see more thorough list at Miskatino Basic Manual)

Commands

• PRINT - prints integer value or constant string (double-quoted) to serial console
• INPUT - allows to read integer value
• REM - just a comment line
• IF - conditional execution, i.e. if x<0; goto 50 (note semicolon instead of "then")
• GOTO - jump to line number
• GOSUB - subroutine call to line number
• RETURN - return from subroutine
• END - stop execution (e.g. end main code to prevent running into subroutine lines)
• DIM - allocate an array (integer or byte)
• DATA - load values to previously allocated array
• PIN - to control the pin output signal (0, 1) or make it input (-1)
• EMIT - send character to UART
• POKE - to put data byte into memory address (register, or io-port)
• assignment to variables via X = 5*Y+ADC(3) form, two first letters of variable are recognized

functions

• ABS - absolute value of argument
• PIN - read logical signal (0, 1) from the given pin
• ADC - read voltage from given analog input
• PEEK - read byte from given memory address (register, or io-port)
• KEY - reads character from UART, non-blocking

Speed test

(current implementation optimizes interpretation of tokens, but does not hard link variables and labels yet)

simple code used:

10 x = 100000
20 if x%5000=0;print x
30 x = x-1
40 if x>=0; goto 20

i.e. about 4 statements per iteration

• on STM32 with -O0: 10 sec
• on STM32 with -O1: 6 sec
• on STM32 with -O2: 5 sec
• on STM32 with -O3: 4 sec
• on Arduino Micro (x=30000): 7 sec (i.e. 23 for 100000)

i.e. roughly 100000 statements per second on STM32 achievable