Today's checkins include support for a comms buffer that sends command bytes to the LCS SER2 with buffering and throttling. The buffer can hold up to 2,048 commands (3 or 9 byte packets) and then sends them to the SER2 no faster than one every 50ms. This behavior is transparent to the client command code, meaning programmers just have to think about what they want their trains to do.
I also added support for the Lionel's "official railroad speeds". For example:
davids@Sprucewood-iMac PyLegacy (master *) % src/cli/engine.py 10 sp limited
sets the speed of the Legacy/TMCC2 engine with TMCC ID#10 to "Limited", which corresponds to[ponds to the absolute speed step of 118. Appropriate speed tables have been implemented for TMCC1 as well (where only speed steps of 0 - 31 are supported)
I've also added a repetition option, which sends the same command multiple times. For example:
davids@Sprucewood-iMac PyLegacy (master *) % src/cli/engine.py 12 -re 10 -boost
sends the "boost" command 12 times to Engine # 10. Why you may ask? Because this is essentially what happens when you press/roll up repeatedly on the multi-controller wheel on the Cab 2. Sending the command multiple times corresponds to holding the "boost" function wheel for a period of time. You could also use the -(re)peat option to ring the bell, say, 5 times or blow the whistle 3 times, etc.
I have been a bit surprised to find that the "Train Brake" functionality actually sends along absolute speed commands as you move the slider control on a Cab 2. In add-on to sending the bytes for the train brake command, the Cab 2 sends multiple decreasing absolute speed commands along as well. It appears that it is these speed commands that actually slow the train down. When you push the slider back up (no brake), a series of increasing speed commands are sent as well. Huh.
Tests are coming along as well. Tests have been added for all of the TMCC1 and TMCC2 3 byte commands. I've done this by entering them in my constants file as hex digits. The test classes use binary representation ("1"'s and "0"'s) taken directly from the documentation and compare values. Not perfect, but it means I had to make the same transcription mistake twice in two different formats.
Here is a summary of the CLI commands that exist today:
- src/cli/acc.py: issue accessory commands
- src/cli/engine.py: issue engine/train commands
- src/cli/halt.py: issue an emergency stop/halt command
- src/cli/route.py: fire routes
- src/cli/switch.py: throw switches
The engine, halt, and route commands can issue either TMCC1 or TMCC2 command sequences. Python classes have been developed (and are in /src/protocol) that are used by the CLI and can be incorporated into other python programs to build up more elaborate command flows (start up a train, ramp up speed over time, ring bells and blow horns, fire routes, etc.)
I will next add the remaining sound effects controls that are defined for the TMCC2 multi-word commands and then on to physical buttons.
-- Dave
