Both Ethernet, UART, USART, USB, SPI, I2C, I2S and CAN might be used as a serial 2-way, buffered byte stream. This is an important abstraction as it allow for an easy, uniform usage of byte streams regardless of underlying technology. To support this I create the same interface on all technologies and an object “stream”…
Functions are a critical part of any modern language, also in PScript. Functions must be declared before they area used. A PScript will start executing the first global statement it find, but it will parse and tag functions on it’s way – so a general good rule is to put the global PScript code at…
With PScript being an interpreter running on the embedded device we need to be realistic about how much we can get in. Plain is a complex language in full, so we need to limit and adjust content with Flasgh size of the package in mind. One example is CAN on STM32. CAN is ca 50…
I have decided on a set of datatypes that I want to support. bit Bit is a 1 bit data variable. Used as a separate variable it will minimum be 8 bits, but used inside a record it get bit packed. uint8 8 bit unsigned integer int8 8 bit signed integer uint16 16 bit unsigned…
uint8 myArray[50] The statement above is an array of 50 bytes. The first element is 0 while the last is 49. uint8 myArray[1..50] This is the same array of 50 elements, but now with the first element as 1 and the last as 50. foreach uint8 x through myArray … end The foreach statement…
To adapt PScript to the current platform I add an interface to add “built-in” content and a C++ library with some content prepared. This is to make PScript as scalable as possible as built-in content needs to be platform specific and depending on how much Flash/SRAM that is available. Records Records are bit-packed and can…
Using GPIO as an example I would like to be notified then an input pin change. To do this in C I use an interrupt function so I need a similar event reception in PScript. The most logical is that the framework check for events in between statements, and if one found execute an event…
Part 1 defined the core control language, but we need to add expressions – both mathematical and boolean. In doing so I also want to add features that I believe will extend the usage of PScript. Mathematical Operators + Addition – Subtraction / Division * Multiplication () Parenthesis & Bitwise And | Bitwise Or << …
The first programming language I learned back in 80’s was BASIC. BASIC was never considered a professional language, but the more modern Visual Basic was and is still in heavy usage as both programming language and scripting language. Python have taken over for a lot of scripting and is making it’s way into heavier applications…
Some of you will remember that I planned a “System Diagram” in Plain! That was a block of configuration code that tied event on modules together. This is exactly what I plan to use UML State Diagrams for. In this diagram we generate a Temp Changed event on one device that is sent to a…