Maerklin for Arduino
This repository contains code to control Maerklin digital model train engines using a Arduino Pro Micro and the L298 bridge driver.
Three demos are provided. All three will blink the lights of a Maerlkin steam engine.
mmtestuart
This demo uses the USART in UART mode to generate the necessary signals. It's the easiest one to understand as it uses the standard Serial interface but generates some of the timing using busy waits.
mmtestmspi
This demo uses the USART in SPI mode to generate the necessary signals. This is similar to the UART variant but implemts SPI mode which is technically simpler but requires direct hardware programming to achieve the correct timing. This still needs some busy waiting code and is thus difficult to combine with other code.
mmtestmspiirq
This demo uses the USART in SPI mode and an interrupt handler to generate the necessary signals. This solution is the most complex one as the entire timing is generated within an interrupt handler. The big advantage of this solution is that the entire signal generation runs in the background and no blocking busy waits are needed. The entire arduinos is thus free to do other operations in the foreground like doing USB communication to send and receive control commands.