The aim of these projects is to help people with a low budget in using the RX ucon, by using:

1. an RX target board, priced around 25 Euros, with embedded debugger.
2. e2studio, usable free-of-charge.
3. GCC, usable free-of-charge.

General instructions for getting started with installation of the tools and starting a new project are in GCC_e2studio_RX65N.md.

The projects are setup to take small incremental steps in understanding and using the RX ucon, and at the time of this writing, are only tested on Windows. Project names all start with RTK5RX65N, I will just use what's behind that in the following summary:

The projects incremental features are:

1. demo00_0: using smart configurator for a simple program,
2. demo00_1: LOCO clock oscillator 240 kHz, TMR CMIA1-interrupt, IO pins, simplifying a project and at the same time shrinking program size,
3. demo01: HOCO clock 16 MHz, IO pin macro for initializing,
4. demo02: HOCO PLL, cascading timers, emulating RX100/RX200 series,
5. demo03: PLL wait states, maximum specified clock speed 120 MHz,
6. demo03_144: overclocking the RX65N, 20% test at 144 MHz,
7. demo04: using different integer number sizes, Arduino-style functions micros() and millis(),
8. demo05: IRQ-interrupt
9. demo06: pin name macro, "bare metal" io pin control, iopin library,
10. demo07: using C and C -wrappers,
11. demo08: communication LED of Modbus-RTU simulated,
12. demo09: synchronous LED library, uses iopin library
13. demo10: push button LED dimmer, automaton concept, simple dimmer library, pwm simulation in two different ways:
    1. repeated one-shot pulse
    2. timer-interrupts to drive a pin on and off
14. demo11: like demo10 with real pwm using the cloud option board LEDs.
15. demo12: Using a serial library for communication with an SCI-module in UART-mode, "bare metal", but easily extensible. This demo uses SCI5 converted to USB with the cloud option board.

Starting with demo10, two new folders have been added to ease usage of code snippets from the demos above in real projects:

1. lib: gathering of "library" files and Rx65x.h register header
2. doc: some .pdf-documentation about programming concepts used in the demos, as well as the .tex-sources for these documents. For generating the pdf's you can copy portable versions of TeXmaker of TeXstudio onto a windows computer or use an installer version like MikTeX.

Background: Developing both hard- and software, the Renesas RX microcontroller (ucon) has some appealing things to me:

• It's assembly language can be read, like in the Gnu Assembler, as if it were in English language, from left to right.
• It's Endian-setting can be chosen to be Big-Endian, that feels more natural because it starts with the most important things, refining details further on.

These demos show that despite having a board with hardly any embedded IO, you can still develop/test code snippets to be used in real projects.

The projects also show that even with a lot of interrupt vectors and IO-pins to initialize, application programs for the RX don't need much memory.