path: root/manual
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authorThomas Orgis <>2014-06-29 15:59:11 +0200
committerGerrit Rockbox <>2015-02-03 22:41:40 +0100
commit8aa72f07f4bf38e9b898fb8d8042239861b9a423 (patch)
tree5991ee64a6f77b76c16d28cee7584c44972424e0 /manual
parent95fdad5e2827685160a5a669c3e8b4dc783995ad (diff)
Enhancement of the metronome plugin:
- square sine tick and tock sounds (more annoying, more useful;-) - optical indication of tics on display - unification of mode of operation for SWCODEC and HWCODEC (tested on simulator) Both playback and display drawing happen in main loop, always. - operating in two modes now: -- 1. classic dumb metronome --- active when openened as application without file to open --- the usual functionality with tapping and bpm change --- controls indicated on display -- 2. track mode with programmable series of parts --- active when started as viewer for a .tempo file --- differing meters (4/4, 3/4, 6/8, etc.) --- patterns (tick/tock/silence on each beat) --- smooth tempo changes in those tracks This version had lots of testing regarding metronome accuracy, resulting in the realization that PLL A and PLL B differ on the Clip+, causing drift. There is still drift when the timer intervall is too small, so I settled on 2 ms as compromise. This is the final version, after adding documentation and extensive help from Sebastian Leonhardt testing it on slower hardware (YH820), where it works up to 650 actual bpm with display indication. Latest change: Documentation nitpicks. Change-Id: I764c8252526db188352385c5462f9453d882beb9
Diffstat (limited to 'manual')
1 files changed, 174 insertions, 1 deletions
diff --git a/manual/plugins/metronome.tex b/manual/plugins/metronome.tex
index e792498984..760507e9b9 100644
--- a/manual/plugins/metronome.tex
+++ b/manual/plugins/metronome.tex
@@ -1,6 +1,23 @@
This plugin can be used as a metronome to keep time during music
-practice. Adjust the tempo through the interface or by tapping it out
+practice. It supports two modes of operation, depending on it being
+started from the plugin menu or as viewer for tempomap (\verb:.tempo:)
+The sound is a piercing square wave that can be heard well also
+through loud music from a band.
+In addition, the display also indicates the beats while playing
+so that you can discreetly place the device
+in your sight for checking the tempo instead of wearing
+headphones at a concert.
+\subsubsection{Simple Interactive Mode}
+This is the mode of operation that is active when starting the
+plugin directly from the menu. It offers a uniform metronome sound at
+a constant tempo.
+You can adjust the tempo through the interface or by tapping it out
on the appropriate button.
@@ -34,3 +51,159 @@ on the appropriate button.
& Sync tap \\}
+\subsubsection{Programmed Track Mode}
+When starting the plugin as a viewer for tempomap files
+(ending in \verb:.tempo:), it starts in the track mode that offers
+playback of a preprogrammed metronome track consisting out of
+multiple parts, each with possibly different properties.
+In contrast to the simple mode, there exists the notion of
+meter and bars, along with emphasis on certain beats.
+Parts can have these properties:
+ \item finite or infinite duration in bars (navigation only jumps
+ to the beginning of infinite parts),
+ \item differing meters (4/4, 3/4, 6/8, etc., default 4/4),
+ \item differing tempo (always in quarter beats per minute,
+ default 120) with
+ \begin{itemize}
+ \item one tempo per bar or even one tempo per beat, or
+ \item smooth tempo changes with configurable acceleration, and
+ \end{itemize}
+ \item custom beat patterns (tick/tock/silence on each beat),
+ default being emphasis (tick) on first beat, normal sound
+ (tock) on others.
+\paragraph{The button mapping}
+is different to enable navigation in the programmed track.
+ \PluginExit
+ & Exit plugin \\
+ \PluginCancel
+ \opt{HAVEREMOTEKEYMAP}{& \PluginRCCancel}
+ & Stop (stay at position) \\
+ \PluginSelect
+ \opt{HAVEREMOTEKEYMAP}{& \PluginRCSelect}
+ & Start from / Stop at current position \\
+ \PluginLeft{} / \PluginRight
+ \opt{HAVEREMOTEKEYMAP}{& \PluginRCLeft{} / \PluginRCRight}
+ & Seek in track \\
+ \opt{scrollwheel}{\PluginScrollFwd{} / \PluginScrollBack}
+ \nopt{scrollwheel}{\PluginUp{} / \PluginDown}
+ \opt{HAVEREMOTEKEYMAP}{& \PluginRCUp{} / \PluginRCDown}
+ & Adjust volume \\
+ \ButtonRec
+ & Sync tap \\}
+The display indicates the part properties and position in track as such:
+ Metronome Track
+ ---------------
+ "Interlude"
+ 3/4@120 V-25
+ P2/13: B1/5+2
+In this example, the part label is ``Interlude'', the meter is 3/4 and
+the tempo 120 quarter beats per minute (bpm). The volume setting is at -25
+and this is the second part of a track with 13 total. In that part,
+the position is at the second beat of the first bar of five.
+\paragraph{The syntax of programmed tracks}
+in tempomap files follows the format defined by
+Actually, the goal is to keep compatibility between klick and this
+Rockbox metronome.
+The parts of a track are specified one line each in this scheme
+(pieces in [] optional):
+[name:] bars [meter ]tempo[-tempo2[*accel|/accel] [pattern] [volume]
+The bar count and tempo always have to be specified, the rest is optional.
+One example is
+part I: 12 3/4 133
+for a part named ``part I'' , 12 bars long, in 3/4 meter with
+a tempo of 133 quarter beats per minute.
+Tempo changes are indicated by specifying a tempo range and the
+acceleration in one of these ways:
+0 4/4 90-150*0.25
+0 4/4 150-90/4
+16 4/4 100-200
+The first one goes from 90 to 150 bpm in an endless part with 0.25 bpm
+increase per bar. The second one goes down from 150 to 90 with
+4 bars per bpm change, which is the same acceleration as in the first line.
+The last one is a part of 16 bars length that changes tempo from 100 to 200
+smoothly during its whole lifetime (6.25 bpm/bar). For details on how the
+acceleration works, see
+It is also possible to provide a tempo for each individual beat in a part
+by separating values with a comma (no spaces),
+varibeat: 3 4/4 135,90,78,100,120,120,99,100,43,94,120,133
+where the beat duration is first according to 135 bpm, then 90 bpm,
+and so forth. You are required to provide a value for each beat
+in all bars of the part.
+You can provide a pattern that controls how the beats are played:
+ Symbol & Meaning \\
+ \hline
+ X & emphasized beat (Tick) \\
+ x & normal beat (Tock) \\
+ . & silent beat
+Some examples:
+default: 0 4/4 120 Xxxx
+rockon2: 0 4/4 120 xXxX
+ solea: 0 12/4 180 xxXxxXxXxXxX
+shuffle: 0 12/12 120 x.xX.xx.xX..
+ funky: 0 16/16 120 x.x.X..X.Xx.X..X
+The 12/12 for the shuffle create 1/4 triplets. Just do a bit of math;-)
+This is still a metronome, not a drum machine, but it can act like a basic
+one, helping you to figure out a certain rhythm within the meter.
+The UI is developed so that it fits into the display of a Sansa Clip+ and
+that is the hardware device it is tested on. It seems to work reasonably
+on some other models in the simulator.
+At last, a more complete tempomap file:
+# An example track exercising the programmable Rockbox metronome
+# or also
+ lead-in: 1 4/4 120 XXXX 0.5 # 4 emphasized but less loud ticks
+ intro: 4 4/4 120 # standard beat
+tearing down: 4 120-90 # changing tempo from 120 to 90
+ break: 2 1/4 90 # 2 1/4 bars at 90
+ rolling: 2 6/8 90 # 2 6/8 at same tempo (quarters!)
+ rumbling: 4 3/4 90 X.x # 3/4, first (tick) and last (tock)
+ ramp-up: 8 2/4 90-150 # speeding up to 150 bpm again
+ flow: 4 150 # steady 4/4 at 150 bpm
+ death: 8 150-60 # going down to 60
+ final: 1 1/1 60 # one last hit