Firmware version 0.6 available

[stfnmllr]

Today the new firmware version https://github.com/pico-cs/firmware/releases/tag/v0.6.1 is available. It comes with a few additions and changes to the protocol plus some minor bug fixes:

• the ce command was replaced by the mte command
• the cs command was replaced by the mtcv command providing additional configuration options for command repetitions
• the iocmdb command was replaced by the commands ioval, iodir, ioup and iodown (which are nicer fits to the protocol)

The new mt (main track) command class was introduced to support a 'service track' providing service mode programming in the future.

Additional features:

• the refresh buffer size is now a build parameter (PICO_CS_RBUF_SIZE) and can take values between 64..255 (inclusive). The default size is 128.

Happy Railroading!

[trimarco232]

Hi,
I just wrote a DCC bits generator ; it includes the railcom cutout and has exact timing
I did not use the RP2040's PIO peripheral (not yet able to do it), but the PWM, it works perfect
it is interrupt driven, ie. what the ISR needs, is to know if the next bit is a one, or a zero, or the packet end bit
do you thing it is possible, if it makes sense, to adapt my generator to your code ?
I am under arduino framework ...

[stfnmllr]

Hi,
thanks for your question! Using the PIO should be the idiomatic RP2040 way generating DCC signals. A BiDi cutout can be added as an option. May I ask what kind of booster you are using?

[trimarco232]

thanks for the answer !
says, I have yet no booster, I will make (design) them myself, lmd18200 or L6203 ...
they will have dedicated rs485 lines, one for the dcc, and one for the cut out signal, in order to make things as simple as possible ; as a feedback bus, i will probably go for loconet
attached is what I obtain with the pwm peripherals : do better is challenging

[stfnmllr]

Nice, thanks for sharing your plans and I am going to provide information about the PIO DCC timings soon, stay tuned...

[trimarco232]

the timings are with the security gaps of 4us told by Wolfgang Kufer @ https://www.opendcc.de/info/railcom/railcom.html
this was my how to :
at the end of each pwm period, an interrupt is fired ; the isr sets the values of the second (double buffered) next period ; for an exemple, the dcc bit 1 has a period of 116us , and a duty of 58us
if the duty is 0 , the signal stays always LOW ; if duty == period, the signal stays always HIGH
each of the 8 pwm peripherals (called slices, they are independent timers) has 2 pwm outputs ; if one use DCC, cutout and DCC invert, one need 2 slices witch have to be synchronised : this is easy to to do, because one can start slices simultaneously

[stfnmllr]

...added the cutout option to strengthen the PIO argument. Will be part of the next firmware version 0.7 and I am planning to make the start and end times ts, te of the cutout configurable like:

• 26us <= ts <= 32us after end bit (default ts := 26)
• 10us <= te <= 16us before begin of 5th start bit (default te := 12)

[sonnny]

Hi,

 Thank you for this great firmware, I made a demo with android app, youtube link below, source in the description.

youtube demo