Protos

This is the original breadboard of the Mini Commander. Both front and back sides are shown. This card ran for months in the belly of my "cop and hobo" car and sometimes in the base of my Log Loader. Only 2 outputs are wired up, but good enough to do some real world testing. The trackside location does not make for the most optimum signal conditions, and the Mini-Commander receiver circuit has a higher gain to compensate for the lower signal levels.


A couple driver boards to research how to do the final driver design. The drivers had to be capable of delicate levels for LED's, yet also be able to drive a vibration motor. Each driver has a built in "snubber" network and a transient suppressor. It took several passes to arrive at the final artwork, the processor kept resetting from transients from the output drivers.

Moving on to the AC/DC and Beep Commanders... This is a breadboard used to debug the code to do the speed augmentation. These products use the R2LC to control the Loco's, promoting the command standards. The 32 speed-step profile is passed on through to the output drivers, while the 100 speed-step profile is developed inside the on-board PIC Processor. One advantage is the on-board processor can function without the R2LC, and provide many features of conventional operation.

The Sound Commander in it's present form evolved from the two designs presented below. The first, shown below on the left, supported conventional only operation. The design did not develop enough volume as the power stage was not efficient enough. The next spin, shown below on the right, worked well and used a new sound processor with two voices. The only drawback on this design was the inability to operate conventionally at lower track voltages. The final design incorporated all the hardware and firmware fixes and is in current production as the "Sound Commander V2".

There are two processors on the Sound Commander V2. The PIC is the control center of the card, detecting offsets, measuring track voltage, decoding the serial control data, storing the volume settings, and controlling the sound processor through a four bit parallel interface with two strobes. One strobe activates 1 of 16 commands, the other 1 of 16 sounds. The sound processor, aside from storing the sound files, samples the commands from the PIC and plays the appropriate sound. The sound processor firmware is fairly complex, managing the four internal state machines that time slice the sound playback. The state machines track functions like the chuff cadence, prime mover levels and looping, and warning sound voice channel assignment. The voice channels are dynamically assigned to keep as many simultaneous sounds playing as possible.