Introduction
Metal Marshmallow Campfire is a digital effects processor for contact mics, built around the popular Spin FV1 chip. It stores 16 effects at a time. The first 8 are hard coded into the device and cannot be changed. The other 8 can be reprogrammed with different effects using
a simple web interface. The purpose of this post is to document the hard-coded and default effects on Campfire.
Hard Coded Effects
Slots 0 to 7 contain programs that are hard-coded into the Spin FV1's ROM and cannot be changed. Table 1 is a list of these programs, and the effect of the knobs.
Table 1: ROM Effects 0–7
| NUM |
DESCRIPTION |
KNOB A |
KNOB B |
KNOB C |
| 0 |
Chorus–Reverb |
Reverb Mix |
Chorus Rate |
Chorus Mix |
| 1 |
Flange–Reverb |
Reverb Mix |
Flange Rate |
Flange Mix |
| 2 |
Tremolo–Reverb |
Reverb Mix |
Tremolo Rate |
Tremolo Mix |
| 3 |
Pitch Shift |
Pitch +/-4 Semitones |
— |
— |
| 4 |
Pitch–Echo |
Pitch Shift |
Echo Delay |
Echo Mix |
| 5 |
Test |
— |
— |
— |
| 6 |
Reverb 1 |
Reverb Time |
HF Filter |
LF Filter |
| 7 |
Reverb 2 |
Reverb Time |
HF Filter |
LF Filter |
I obtained this list of effects out of the
Spin FV1 Datasheet. These programs are also available in the
Campfire Programmer. Their names begin like "spinsemi_rom_", and the rest of the name describes the effect, for example spinsemi_rom_chor_rev.bin is the chorus reverb hardcoded into Slot 0.
Reprogrammable Effects
Slots 8 to F are reprogrammable. The default programs that come on a new Campfire are documented in Table 2.
Table 2: Reprogrammable Effects 8–F
| NUM |
DESCRIPTION |
KNOB A |
KNOB B |
KNOB C |
| 8 |
Stereo Distortion |
— |
— |
— |
| 9 |
Mono Distortion |
Distortion Threshold |
LP Filter |
Output Gain |
| A |
Reverb |
Shimmer Level |
Reverb Time |
HF Damping |
| B |
Shimmer |
Reverb Time |
Amount of Treble in Reverb Loop |
Shimmer |
| C |
Ping Pong |
Delay Time |
Feedback |
Damping |
| D |
Arpeggiator |
Volume |
Speed |
Number of Notes in Arpeggio |
| E |
Guitar Tuner |
Note Select DEADGBE |
Output Gain |
— |
| F |
Mixer |
Out 1 Gain −20to+20dB |
Input Blend |
Out 2 Gain −20to+20dB |
These are subject to change in future manufacturing runs of Campfire, but all of these are available in the
Campfire Programmer.
Future Work
Some of the default programs are ones that I wrote or modified myself. I intend to make the source code for them available here in the future. If you need it before I have done that, please contact me.
