A nightstand noise generator based on M5Stack Atom Echo and integrating with Home Assistant
enclosure: targeted plunger for the flush button, M2.5 standoff pilot
Two unrelated tweaks driven by trial-fitting the first assembled unit:
The Atom Echo's button isn't a raised tactile dome — it's a flush
D-shaped cap on one half of the top face, with the surrounding plastic
fixed. A full-face plunger gets stopped by that fixed plastic before
the button can move. Replaced the 24×24 mm centered plunger with an
8×8 mm plunger sized to fit inside the button cap (10×10 mm bounding
box, 1 mm clearance per side), offset −2.75 mm / +1.7 mm in chassis
coords so it lands over the button measured at (20, 11) from the
rear-left mounting post on the soldered protoboard. Snooze cap stays
visually centered on the chassis; only the plunger inside it moves.
Bumped the daughterboard standoff pilot from 1.6 mm (M2 self-tap) to
2.2 mm (M2.5 self-tap) — the 1.6 mm holes were way too tight for the
M2.5 screws actually being used, and 2.2 leaves a small bit of give so
the screws thread cleanly without splitting the PLA wall.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
+63
-11
+7
enclosure/enclosure.scad
+7
enclosure/enclosure.scad
···
37
37
atom_z_bottom])
38
38
cube([atom_w, atom_d, atom_body_h]);
39
39
40
+
// Reference geometry — the Atom's button cap on its top face. The
41
+
// plunger should land inside this footprint when viewed from above.
42
+
%translate([button_cx - button_cap_w / 2,
43
+
button_cy - button_cap_d / 2,
44
+
atom_z_bottom + atom_body_h])
45
+
cube([button_cap_w, button_cap_d, 0.5]);
46
+
40
47
// Reference geometry — speaker, sitting on the four bottom-plate posts.
41
48
// Frame plate at z = spk_post_h; magnet hangs spk_magnet_protrusion below;
42
49
// cone tip rises (spk_total_d - spk_magnet_protrusion) above.
+42
enclosure/lib/params.scad
+42
enclosure/lib/params.scad
···
27
27
header_right_pin_count = 4;
28
28
header_edge_offset = 2.0;
29
29
30
+
// Button cap on the Atom's top face: a roughly D-shaped piece of plastic
31
+
// flush with the surrounding fixed top, depresses below the surface when
32
+
// pressed. The snooze cap's plunger has to fit *inside* this footprint
33
+
// — anything overhanging onto the surrounding fixed plastic gets stopped
34
+
// before reaching the switch. Treated as a rectangular bounding box for
35
+
// plunger sizing.
36
+
button_cap_w = 10;
37
+
button_cap_d = 10;
38
+
39
+
// Position of the button cap center on the protoboard, measured from
40
+
// the rear-left mounting hole of the Adafruit 1214 (the corner closest
41
+
// to the speaker / cable exit). User coordinate convention:
42
+
// +X = right (along the protoboard's long axis)
43
+
// +Y = forward (toward the front of the enclosure)
44
+
button_x_from_rear_left_post = 20;
45
+
button_y_from_rear_left_post = 11;
46
+
47
+
// Margin between the plunger and the button cap edge on each side, to
48
+
// absorb print tolerances and assembly misalignment without the plunger
49
+
// catching on the surrounding fixed plastic.
50
+
plunger_clearance = 1;
51
+
52
+
plunger_w = button_cap_w - 2 * plunger_clearance;
53
+
plunger_d = button_cap_d - 2 * plunger_clearance;
54
+
30
55
// ============================================================
31
56
// MAX98357A I2S amp breakout (Adafruit 3006 / generic clone)
32
57
// See: reference/signal-chain.md
···
68
93
dboard_screw_pattern_d = 25.4; // mounting hole pattern, short axis
69
94
dboard_pin_h = 6;
70
95
dboard_standoff_h = 6;
96
+
dboard_standoff_d = 5;
97
+
dboard_standoff_pilot_d = 2.2; // M2.5 self-tap pilot into PLA
71
98
72
99
// ============================================================
73
100
// Snooze cap + well
···
205
232
206
233
snooze_well_cy = front_margin + snooze_well_d / 2;
207
234
spk_grille_cy = front_margin + snooze_well_d + zone_gap + spk_frame / 2;
235
+
236
+
// Button position derived in chassis coordinates. The snooze cap stays
237
+
// visually centered above the chassis; the plunger inside it is offset
238
+
// to land precisely over the Atom's button cap.
239
+
rear_left_post_x = outer_w / 2 - dboard_screw_pattern_w / 2;
240
+
rear_left_post_y = wall_t + snooze_well_cy + dboard_screw_pattern_d / 2;
241
+
242
+
button_cx = rear_left_post_x + button_x_from_rear_left_post;
243
+
button_cy = rear_left_post_y - button_y_from_rear_left_post;
244
+
245
+
snooze_cap_cx = outer_w / 2;
246
+
snooze_cap_cy = wall_t + snooze_well_cy;
247
+
248
+
button_offset_x = button_cx - snooze_cap_cx;
249
+
button_offset_y = button_cy - snooze_cap_cy;
+3
-5
enclosure/parts/bottom-plate.scad
+3
-5
enclosure/parts/bottom-plate.scad
···
60
60
}
61
61
62
62
module daughterboard_standoffs() {
63
-
standoff_d = 5;
64
-
standoff_id = 1.6; // M2 self-tap pilot into PLA
65
-
66
63
for (sx = [dboard_cx - dboard_screw_pattern_w / 2,
67
64
dboard_cx + dboard_screw_pattern_w / 2])
68
65
for (sy = [dboard_cy - dboard_screw_pattern_d / 2,
69
66
dboard_cy + dboard_screw_pattern_d / 2])
70
67
difference() {
71
68
translate([sx, sy, 0])
72
-
cylinder(h = dboard_standoff_h, d = standoff_d);
69
+
cylinder(h = dboard_standoff_h, d = dboard_standoff_d);
73
70
translate([sx, sy, -EPS])
74
-
cylinder(h = dboard_standoff_h + 2 * EPS, d = standoff_id);
71
+
cylinder(h = dboard_standoff_h + 2 * EPS,
72
+
d = dboard_standoff_pilot_d);
75
73
}
76
74
}
77
75
+11
-6
enclosure/parts/snooze-cap.scad
+11
-6
enclosure/parts/snooze-cap.scad
···
1
1
// Snooze cap — translucent press button. Drops into the well in the top
2
2
// panel from below; the flange catches on the underside of the top panel
3
-
// as the up-stop. The Atom Echo's tactile dome under the plunger acts as
4
-
// the return spring.
3
+
// as the up-stop. The Atom Echo's flush button cap (a D-shaped piece on
4
+
// one half of its top face) sits under the plunger and acts as the
5
+
// return spring. The plunger is sized to fit inside the button cap's
6
+
// footprint and is offset from the cap's centerline to land over it —
7
+
// the surrounding plastic on the Atom's top face is fixed, so a
8
+
// full-face plunger would be stopped before reaching the switch.
5
9
//
6
10
// Print in translucent or white PLA so the SK6812 LED diffuses through.
7
11
// Print upside-down (cap top on the build plate) for the cleanest first
···
40
44
flange_d = snooze_well_d + 2 * snooze_cap_flange_overhang;
41
45
42
46
module snooze_cap() {
43
-
// Plunger — centered over the Atom Echo footprint.
44
-
translate([(flange_w - atom_w) / 2,
45
-
(flange_d - atom_d) / 2,
47
+
// Plunger — sized to fit inside the Atom's button cap, offset from
48
+
// the snooze cap's centerline to land over the button.
49
+
translate([flange_w / 2 + button_offset_x - plunger_w / 2,
50
+
flange_d / 2 + button_offset_y - plunger_d / 2,
46
51
z_plunger_bot])
47
-
cube([atom_w, atom_d, plunger_h]);
52
+
cube([plunger_w, plunger_d, plunger_h]);
48
53
49
54
// Flange — wider than the well opening, catches the underside of
50
55
// the top panel.