Add blog post on undocumented Wavedrum modes.

2 files changed, 118 insertions, 4 deletions

diff --git a/non-posts/wavedrum/index.skr b/non-posts/wavedrum/index.skr
index f1b2bfc..7542fa8 100644
--- a/non-posts/wavedrum/index.skr
+++ b/non-posts/wavedrum/index.skr
@@ -19,9 +19,8 @@
 
  (p [It is possible to load firmware from the microSD card by pressing
      ,(em [Write]) and ,(em [1]) while powering on the Wavedrum,
-     followed by pressing ,(em [Write]) again (another undocumented
-     mode can be entered by pressing ,(em [Write]) and ,(em [Mode])
-     while powering on).])
+     followed by pressing ,(em [Write]) again.  There are other undocumented
+     modes that I described in a blog post.])
 
  (p [The Wavedrum unfortunately rejects any modified firmware.  The
      Oriental edition will not load the firmware of the Original/Black
@@ -31,10 +30,11 @@
      out how the Wavedrum validates the data on the SD card before
      deciding to reject them.])
 
-
  (h2 [Blog posts])
 
  (ul
+   (li (ref "/posts/2022-01-24-wavedrum-modes.html"
+            "Undocumented Wavedrum modes"))
    (li (ref "/posts/2013-08-11-hacking-the-wavedrum.html"
             "Hacking the Wavedrum"))
    (li (ref "/posts/2013-10-31-wavedrum-data-comparison.html"
diff --git a/posts/2022-01-24-wavedrum-modes.md b/posts/2022-01-24-wavedrum-modes.md
new file mode 100644
index 0000000..ca00709
--- /dev/null
+++ b/posts/2022-01-24-wavedrum-modes.md
@@ -0,0 +1,114 @@
+title: Undocumented Wavedrum modes
+date: 2022-01-24 00:00
+tags: DIY, electronics, music, hacking, wavedrum
+---
+
+
+The manual mentions two special modes that can be entered by holding
+down buttons while powering on: hold down `Write` while powering on
+and you can reset to factory settings; hold down `Mode` while powering
+on and you can double the output volume.
+
+The manual does *not* mention these additional modes:
+
+## Information modes
+
+These modes only provide version information before booting up
+normally.
+
+- **Hold button 1.** The display shows `SyS`, followed by the version.
+  In my case that's `2.02`.  It then proceeds to boot up.
+        
+- **Hold button 2.** The display shows `Sub`, followed by the version.
+  In my case that's `1.10`.  It then proceeds to boot up.
+  
+- **Hold button 3.** The display shows `dat`, followed by the version.
+  In my case that's `2.02`.  It then proceeds to boot up.
+
+- **Hold button 4.** The display briefly shows `InF`, and then cycles
+  through the version information that can be obtained with the
+  previous three modes.
+
+
+## Update modes
+
+These modes allow changing the firmware.
+
+- Hold **Write** and **button 1**.  The display blinks `SyS`.  Upon
+  pushing *Write* it displays `Lod` followed by a blinking `End`,
+  presumably loading firmware.  (From where?)  It is possible to push
+  the buttons *1*, *2*, *3*, or *4* to switch between `SyS`, `Sub`,
+  `dSP`, and `S_d`, respectively.  But the *Write* button only has an
+  effect when `SyS` (button 1) is selected.
+        
+- Hold **Write** and **button 2**; the display blinks `Sub`.  This is like the
+  previous mode, except that `Sub` is selected.
+  
+- Hold **Write** and **button 3**; the display blinks `dSP`.  This is like the
+  previous modes, except that `dSP` is selected.
+        
+- Hold **Write** and **button 4**; the display blinks `S_d`.  This is like the
+  previous modes, except that `S_d` is selected.
+
+Finally, there's the well-known mode to reset to factory settings by
+holding **Write** and **Mode** while powering on.
+
+
+## Test modes
+
+- Hold **button 1** and **button 3**; the display briefly shows `SLF`,
+  probably for "self test".  It then shows `SyS`, followed by the
+  version number and then lights up all LEDs.  Pushing *Mode* then
+  lights up only the LED above the *Write* button.  Hitting *Write*
+  advances the LED to the next button, and so on.
+        
+  When the display is tested, hit *Mode* to get to test the
+  *Value* knob; hit *Mode* again to test the *Value* knob's range from 0 to 99; hit it yet again to test
+  the range from 0 to 7.  That's all that can be tested here.
+
+- Hold **button 1** and **button 4**; the display shows `Aud.`.  It
+  then lights up LED 1 and displays `A.In`, presumably to test audio
+  input.  Selecting *button 2* it shows `OFF` and the output goes
+  silent.  Selecting *button 3* shows `Pie.`; the signal of the piezo
+  sensors is passed straight to the output.  Selecting *button 4*
+  shows `ALG.` and you can hear the sounds produced by a simple test
+  algorithm when you play the head and rim.
+
+- Hold **button 2** and **button 4**; the display shows `CAL.`,
+  probably meaning "Calibration".  It lights up LED 1 and displays the
+  current value of the pressure sensor.  When you select *button 2*
+  and strike the head, the display shows the corresponding velocity.
+  When you select *button 3* and strike the rim, the display shows the
+  corresponding velocity.  Hold down *button 3* and you see what seems
+  to be an amplification factor.  By default this shows `0.75`.  This
+  can be adjusted with the *Value* knob in the range from `0.00` all
+  the way to `4.00`.  There does not seem to be a way to save changes.
+        
+  Selecting *button 4* the display shows where and how strongly the
+  drum is hit.
+
+- Hold down **buttons 1, 2, 3, and 4**, and also hold **Mode**; the
+  display briefly shows `deb`, which I assume means "debug".  It then
+  seems to boot up normally, but upon completion will have entered an
+  absolutely bizarre mode where the *buttons 1 and 2* are used to go
+  down or up in a list of presets from `01` to `26`; similarly,
+  *buttons 3 and 4* are used for selecting one of 26 presets, probably
+  for the rim sounds.
+  
+  The value dial goes from `050` to `500`, but I don't know what value it
+  controls.  *Mode* and *button 1* start a constant fast
+  automatic trigger of the head.  Hitting the combo again stops the
+  automatic trigger.
+  
+  *Mode* and either *button 2* or *button 3* seems to mute the audio.
+  *Mode* and *button 4* mutes all generated sounds and passes the
+  unprocessed sound of the piezo sensors through.
+  
+  I'm not sure what the *Write* button does; pushing it multiple times
+  seems to cycle between four different values, but it is not clear
+  what they are.  When holding *Mode*, pushing *Write*
+  twice selects the next reverb, cycling from `r00` to `r10`.
+ 
+
+Read [more posts about the Wavedrum here](/tags/wavedrum.html).
+