StompStation PRO Routing

# StompStation PRO Routing

Firmware 2.x replaced the PRO's fixed 1.5.12 chain with a router. This page
records what the router node holds and how the pedal treats a write, read from
the 2.0.10 and 2.2.6 firmware (the router code is identical in both apart from
how parallel branches mix) and from a 2.0.10 pedal's schema. On a pedal at
2.0.10, writes covering every rule below (fixed positions, moves, two- and
three-way banks, connector normalisation, duplicates, unknown paths, malformed
values, both chain actions and a preset reload) read back exactly as described.
Facts not yet checked on hardware are marked *(unconfirmed)*.

## The value

`root\app\router` has type `router`. It is live state inside the loaded
preset; it is not a global setting. Its value is a list of rows; the PRO has
one row of 14 positions, the StompStation CORE one row of 5. Take the size from
the lengths: a row has `2C - 1` strings for `C` positions.

```
row = [ B0, L1, B1, L2, B2, ..., L13, B13 ]
B   = "" | "root\\app\\<block>"      an empty position or a block's node path
L   = "s" | "p"                       series or parallel, between B(c-1) and B(c)
```

Input and output are implicit, before `B0` and after `B13`; neither
`root\app\output` nor anything else stands for them. Every position is stereo.

A browse also returns `def` (the default chain) and `fixed`, a row of 27
booleans interleaved like the value (even indexes are positions, odd ones
connectors). On the PRO the amp (position 6), delay (11) and reverb (12) are
fixed; no connector is.

The default chain, which `root\app\output\d_chain` restores and which every
preset without a router record loads (all presets saved on 1.5.12), is the old
fixed order:

```json
[["root\\app\\gate","s","root\\app\\pitch","s","root\\app\\exp","s","root\\app\\comp","s","root\\app\\mod_pre","s","root\\app\\drive","s","root\\app\\amp","s","root\\app\\ir","s","root\\app\\eq","s","","s","root\\app\\mod","s","root\\app\\delay","s","root\\app\\reverb","s",""]]
```

`root\app\output\c_chain` empties every position that is not fixed and sets
every connector to `"s"`. Both actions run when written `{"value":"run"}` and
return to `idle`.

## Parallel

A run of positions joined by `"p"` is one parallel bank. Each position in it is
one branch of exactly one block; every branch receives the bank's input, and
their outputs are summed without gain compensation into the next position.
Delay ∥ reverb after the modulation block:

In series a switched-off block bypasses itself, as on 1.5.12. Inside a bank the
firmware versions differ:

How a bank sounds was read from the firmware, not measured *(unconfirmed)*:

| Branch in a bank | 2.0.10 | 2.2.6 |
|---|---|---|
| block on | the block's output | the block's output |
| block off | nothing | the block's tail only |
| empty position | nothing | the dry input |
| no branch contributes | the dry input passes | silence |

## Blocks

Placeable blocks are the children of `root\app` whose `item_type` is `block`
and whose first child is `on_off`. Their style string carries `cat:`, `color:`
and `img:`. On 2.0.10: gate, pitch, exp, comp, mod_pre, flanger, chorus, drive,
amp, ir, eq, eq2, crossover, mod, delay, delay2, reverb, reverb2, pickup. 2.2.6
adds pitch_time, dyna_comp, parametric_eq, dtchr and rotary; its
`root\app\pcm42` node is never connected and must not be offered. A block's
parameters keep their 1.5.12 meanings. There are no mixer or split nodes: a
bank's balance comes from each block's own mix and level controls. The
crossover is an ordinary single-position block.

Blocks outside the chain stay live and writable but are silent, are not saved,
and reset to their defaults when a preset loads.

## Writing

Write the whole value as a raw JSON array, with nothing else in the object:

```
write root\app\router:{"value":[[...27 strings...]]}
```

The pedal applies these rules, in order:

1. A value that is not exactly one row of 27 JSON strings changes nothing.
2. Connectors are lower-cased; anything but `"p"` becomes `"s"`.
3. Fixed positions keep their current block whatever the write says.
4. Block strings are not validated: an unknown path is stored and acts as an
   empty position.
5. A block written twice keeps the later position; a copy of a fixed block is
   always the one dropped.
6. A write that changes nothing does nothing; any change applies live (a
   short dip in the output) and marks the preset edited.

The reply echoes the request exactly, whether it was applied, normalised or
ignored, so read `root\app\router` afterwards and treat that as the result.

Saving a preset stores the router as its first record,
`root\app\router:{"value":[[...]]}`, and drops the parameters of every block
not in the chain. A preset document must keep that record on export and import.

## Global quick controls

`root\assign1` to `root\assign4` (F1 to F4) are global, not per preset, and on
2.x refer to positions such as `0_2` rather than block paths, so they follow a
position when blocks move *(unconfirmed)*.

Firmware 2.x replaced the PRO’s fixed 1.5.12 chain with a router. This page records what the router node holds and how the pedal treats a write, read from the 2.0.10 and 2.2.6 firmware (the router code is identical in both apart from how parallel branches mix) and from a 2.0.10 pedal’s schema. On a pedal at 2.0.10, writes covering every rule below (fixed positions, moves, two- and three-way banks, connector normalisation, duplicates, unknown paths, malformed values, both chain actions and a preset reload) read back exactly as described. Facts not yet checked on hardware are marked (unconfirmed).

The value

root\app\router has type router. It is live state inside the loaded preset; it is not a global setting. Its value is a list of rows; the PRO has one row of 14 positions, the StompStation CORE one row of 5. Take the size from the lengths: a row has 2C - 1 strings for C positions.

row = [ B0, L1, B1, L2, B2, ..., L13, B13 ]
B   = "" | "root\\app\\<block>"      an empty position or a block's node path
L   = "s" | "p"                       series or parallel, between B(c-1) and B(c)

Input and output are implicit, before B0 and after B13; neither root\app\output nor anything else stands for them. Every position is stereo.

A browse also returns def (the default chain) and fixed, a row of 27 booleans interleaved like the value (even indexes are positions, odd ones connectors). On the PRO the amp (position 6), delay (11) and reverb (12) are fixed; no connector is.

The default chain, which root\app\output\d_chain restores and which every preset without a router record loads (all presets saved on 1.5.12), is the old fixed order:

[["root\\app\\gate","s","root\\app\\pitch","s","root\\app\\exp","s","root\\app\\comp","s","root\\app\\mod_pre","s","root\\app\\drive","s","root\\app\\amp","s","root\\app\\ir","s","root\\app\\eq","s","","s","root\\app\\mod","s","root\\app\\delay","s","root\\app\\reverb","s",""]]

root\app\output\c_chain empties every position that is not fixed and sets every connector to "s". Both actions run when written {"value":"run"} and return to idle.

Parallel

A run of positions joined by "p" is one parallel bank. Each position in it is one branch of exactly one block; every branch receives the bank’s input, and their outputs are summed without gain compensation into the next position. Delay ∥ reverb after the modulation block:

[["root\\app\\gate","s","root\\app\\pitch","s","root\\app\\exp","s","root\\app\\comp","s","root\\app\\mod_pre","s","root\\app\\drive","s","root\\app\\amp","s","root\\app\\ir","s","root\\app\\eq","s","","s","root\\app\\mod","s","root\\app\\delay","p","root\\app\\reverb","s",""]]

In series a switched-off block bypasses itself, as on 1.5.12. Inside a bank the firmware versions differ:

How a bank sounds was read from the firmware, not measured (unconfirmed):

Branch in a bank	2.0.10	2.2.6
block on	the block’s output	the block’s output
block off	nothing	the block’s tail only
empty position	nothing	the dry input
no branch contributes	the dry input passes	silence

Blocks

Placeable blocks are the children of root\app whose item_type is block and whose first child is on_off. Their style string carries cat:, color: and img:. On 2.0.10: gate, pitch, exp, comp, mod_pre, flanger, chorus, drive, amp, ir, eq, eq2, crossover, mod, delay, delay2, reverb, reverb2, pickup. 2.2.6 adds pitch_time, dyna_comp, parametric_eq, dtchr and rotary; its root\app\pcm42 node is never connected and must not be offered. A block’s parameters keep their 1.5.12 meanings. There are no mixer or split nodes: a bank’s balance comes from each block’s own mix and level controls. The crossover is an ordinary single-position block.

Blocks outside the chain stay live and writable but are silent, are not saved, and reset to their defaults when a preset loads.

Writing

Write the whole value as a raw JSON array, with nothing else in the object:

write root\app\router:{"value":[[...27 strings...]]}

The pedal applies these rules, in order:

A value that is not exactly one row of 27 JSON strings changes nothing.
Connectors are lower-cased; anything but "p" becomes "s".
Fixed positions keep their current block whatever the write says.
Block strings are not validated: an unknown path is stored and acts as an empty position.
A block written twice keeps the later position; a copy of a fixed block is always the one dropped.
A write that changes nothing does nothing; any change applies live (a short dip in the output) and marks the preset edited.

The reply echoes the request exactly, whether it was applied, normalised or ignored, so read root\app\router afterwards and treat that as the result.

Saving a preset stores the router as its first record, root\app\router:{"value":[[...]]}, and drops the parameters of every block not in the chain. A preset document must keep that record on export and import.

Global quick controls

root\assign1 to root\assign4 (F1 to F4) are global, not per preset, and on 2.x refer to positions such as 0_2 rather than block paths, so they follow a position when blocks move (unconfirmed).