Experiments with the XMC_2GO_XMC1100 eval board

Infineon has been pushing their XMC line of Cortex M based micro-processors pretty hevily in the last few months. Their dev boards are reasonably cheap (~$10-20USD depending on what you're looking for), and feature a JLINK based SWD debugger, which is pretty impressive. The Segger JLink debugger is a very nice piece of kit, so knowing this was on the boards was very appealing.

They also have a promotion or similar going on with ARM/Keil, where you can get the latest version of the Keil ARM compiler (uVision 5), and use that. Having used the Keil compiler for other processors, this was also attractive. There is a code limit of 128KB, but when you're using the bottom end processors, you don't have any more flash than that anyway, so that's not really an issue.

Hardware

The XMC_2GO_XMC1100 is a nice little eval board with the XMC1100 on it, and also an XMC4200 used for the JLINK SWD interface.  
The PCB comes with 0.1-inch (2.54mm) headers for  letting you plug it into a standard breadboard.
The board is powered by USB, and the USB connection is used both for the JLINK connection, but also acts as a USB UART at the same time, which is super convinient..  

Useful Links for Getting Started

• XMC_2GO_XMC1100 User Manual
• Programming the XMC1100 board without using DAVE or the Keil tools
• Infineon Initial startup guide for the XMC2GO board
• Writing the first program
• Getting started with using Keil uVision 5 with the XMC_2GO board

Getting started with the kit was a little frustrating. The link on the packaging is an old link, and the website re-directs you, so you need to do a little digging to find how to start using the XMC_2GO_XMC1100 kit. The default development tools to use with it is the Infineon DAVE system. after getting the standard example program running, (blink some LEDs!) it was time to try a few other interesting things.

A Simple CLI interface

This was a little fiddly to get working, but it was mostly in setting up the UART pins for the serial link. The code is based on the simple CLI interface described here.
To get it to work I needed to make some functions to read and write characters to the UART. You can get the files here:

• main.c
• main.h
• cli.c
• cli.h

• Initialises the CLI ( cli_init )
• Normally there would be some steps for initialising the clocks, but the default state of the clocks is to start in the 32MHz mode, so nothing was needed here. Additionally, the Uart initialisation code (in XMClib) doesn't seem to handle a different clock rate currently.
• Sets up the UART pins and starts up the UART. ( init_UART ) This was quite tricky, and i still don't fully understand how the pin assignment for serial input works on the XMC1100. Serial output is easier.
• Sets up the sysclock to call the flashing led interrupt ( SysTick_Handler )
• Contains the functions to read and write to the serial port as used by cli.c
• Contains the list of functions that the CLI can use, as well as the code for this. The current functions are mostly just useless toy commands

Capacitive Touch