Capsule Build Guide

One colour per signal, so the wires match the diagrams exactly. Rough wire lengths: battery to power board 8 cm, power board to screen 12 cm, power board to amp 14 cm, screen plugs to amp 12 cm, screen plugs to mic 18 cm, speaker 15 cm.

Three diagrams cover it all: power (including the mic's power), audio (mic and amp signals), and LEDs (later).

1. Battery wires to the power board

   The board sits upside down in the sled (USB-A facing up), so solder every wire on the USB-A side. The board sits between two side walls, so bend each wire straight up off its pad: nothing may stick out past the edge of the board. Cut the holder's wires to about 8 cm. Tin the pads first, then solder holder red → B+ and holder black → B−.

   The holder is a parallel type (it says PARALLEL inside), so the two cells already share these two wires.

2. Power button

   Solder an 8 cm wire to two diagonally opposite legs of the 6×6 button. Check with the multimeter's beep mode: it should beep only while you press.

   Solder one wire to K and the other to B− (ground), on the USB-A side like A1. B− can take two wires; tin it well. Use brown for the K wire and black for B−.

3. 5V output harness

   Two wires go on each output pad, one for the screen and one for the amp. Cut two red wires (screen 12 cm, amp 18 cm) and two black ones the same lengths. Strip 4 mm, twist each pair's ends together, tin them, and solder the red pair onto 5V+ and the black pair onto 5V−, on the USB-A side, wires pointing straight up.

   No splice needed. The LEDs come later: you'll splice them into the amp's red and black wires then.

4. First power test

   Put both cells in, matching the + marks. Press the button once. Measure between 5V+ and 5V−: you should see about 5.0–5.2 V.

   Find out how yours turns off: on most of these boards it's a double press or a long press. Plug a USB-C charger into the power board: the 4 little LEDs should show charging. Then take the cells out again.

1. Power the screen

   Plug a 4-pin cable into the CYD's P1 socket. Read the labels printed next to it on the board to identify the wires: VIN TX RX GND.

   Solder 5V branch → VIN and GND branch → GND. Cut TX and RX short and cover them with heat-shrink.

   Test: cells in, press the button, and the screen lights up. Cells out again.

2. Find the IO4 and IO16 pads

   On the back of the CYD there's a white square RGB LED (LED1) with 6 small solder pads. The factory schematic shows IO4 and IO16 wired straight to two of LED1's pads; the resistors (R16, R17, R20) sit on the 3.3V side, so their ends never beep to a GPIO.

   Set the multimeter to beep mode. Put one probe on pin 26 of the ESP32 module (see the picture below) (the second pad up the right edge; the bottom one is pin 25 = GPIO0) and touch each of LED1's 6 pads in turn, left side first. The pad that beeps is IO4; mark it with a pen. Repeat with pin 27 to find IO16.

3. Solder the two pad wires

   Solder a purple wire to the IO4 pad of LED1 (amp data) and a grey wire to the IO16 pad of LED1 (LEDs, later). These pads are tiny and 22 AWG is thick: strip only 2 mm, tin the wire, add flux, and touch the iron for a second or two. If it won't sit on the pad, splice a short piece of thin wire from a spare CYD cable onto the end and solder that instead.

   Put a dot of hot glue over each wire about 1 cm from the joint, so a tug can't rip the pad off. The RGB LED may flicker faintly when sound plays. That's harmless; desolder its red and green resistors if it bothers you.

4. CN1 and P3 cables

   Plug a 4-pin cable into CN1 and identify it by the printed labels: GND IO22 IO27 3.3V. You use all four.

   Plug a cable into P3: GND IO35 IO22 IO21. You only use the second contact, which is GPIO35. (Your board prints IO35 here, but that's a misprint: your beep test shows this contact goes to the module's pin 7 = GPIO35, and GPIO35 is the touch screen's chip-select. Use GPIO35 in the firmware.) Cut the other three short and heat-shrink them. IO21 runs the screen backlight; never connect anything to it.

5. Wire the mic (18 cm wires)

   The mic's flat side (no chip) goes against the inside of the tube, so solder from the chip side and keep the flat side smooth. No pins or solder bumps should stick out on the flat side.

   • VDD ← CN1 3.3V (orange)
   • GND ← CN1 GND
   • L/R → short jumper to the mic's own GND pin (this picks the left channel)
   • SCK ← IO22 (blue)
   • WS ← IO27 (green)
   • SD → P3 IO35 (yellow)

   IO22 and IO27 each go to two places (mic and amp). Splice them: strip the CN1 wire, add a branch, solder, heat-shrink.

6. Wire the amp

   Your amp already has its pins soldered, pointing down. Solder the wires straight onto the pins, close to the board, and heat-shrink each one. Keep the wires running straight down: the pins pass through a slot in the sled shelf. Leave the wires long and trim them once everything is mounted: VIN and GND 18 cm, BCLK and LRC 15 cm, DIN 20 cm. The DIN wire is the same wire as the screen's IO4 pad wire (A7): solder it to both while the amp sits loose next to the screen.

   • VIN ← 5V branch · GND ← GND branch
   • BCLK ← IO22 (blue) · LRC ← IO27 (green)
   • DIN ← IO4 pad (purple)
   • GAIN and SD: nothing

7. Bench test

   Connect the speaker to the amp's green terminal for now (+ to +), put the cells in, and power on. With test firmware loaded (see the pin map), check that the screen works, a test sound plays, and the mic picks you up. Cells out, speaker off the terminal.

1. Dry-fit first

   Before any glue, push each collar (the orange ring part) into each end of the tube and twist about ⅛ turn until it stops. If it's stiff, lightly sand the three small bumps on the sleeve.

   Slide the empty sled up the tube from the bottom: its thick side edges ride in the rails inside. The new sled is snug by design. If it binds, sand the outside of the edge strips lightly and try again; take off a little at a time.

2. Heat-set inserts (8)

   Iron around 230 °C. Press each insert in straight, stop when it's flush, and hold it still for a few seconds.

   • Screen posts: they print as a sheet of 20 (file 1b). Snap 4 off with a small twist at the base, scrape off any nub, then melt one insert into the flat end of each (the end without the peg). Keep the rest as spares
   • Top lid: 4 inserts inside, at the 4 holes in the corners of the square pocket

3. Speaker into the top lid

   Solder two 15 cm wires to the speaker: red to + (marked with a red dot or +), black to −.

   Set the top lid open-end-down on the table. Lower the speaker in face down, with its square frame's corners in four of the octagon's corners and its holes over the inserts. Fasten with 4 × M3×6. Snug is enough; the frame is thin.

4. Spacer

   Drop the 3 mm octagon spacer in on top of the speaker frame. Its 4 notches sit over the screw heads. Feed the speaker wires through the middle.

   

5. Glue the top collar to the top lid

   Dry-fit first: collar ring against the lid, sleeve pointing away, octagon flats lined up exactly. Then put a thin bead of super glue gel on the lid's rim, near the outer edge. Press together and hold for 60 seconds. The speaker wires come out through the sleeve.

6. Glue the bottom collar to the bottom lid

   Same as B5, flats lined up. Let both caps cure for 10 minutes before you twist them.

Do these in order. Each picture shows the sled after that step.

1. Power board in the bottom tray

   On the back of the sled, the bottom tray has a small ledge on each side wall and an open floor. Hold the power board upside down (USB-A up, USB-C underneath), just above the side walls, slide it in toward the battery holder until it touches the two backstops at the inner end (they stop a plugged-in charger from pushing it back), then lower it so its two long edges rest on the ledges. The USB-C ends up at the outer edge, lined up with the charging hole in the tube. Nothing touches the underside, and there is no lip over the edges, so all the pads stay open.

   Run a bead of hot glue along both long edges where the board meets the walls. The little notches in the ledges sit under the pads near one edge, so their solder bumps don't lift the board.

   

2. Button on its post

   The post next to the power board holds the button. Glue the button body to the post's pad with the plunger facing outward (away from the sled).

   

3. Battery holder

   Stand the holder on the back of the sled between the two shelves, open side facing out. Pass 2 zip ties through the slots beside it and around the holder. Pull them snug and trim. Route its wires down to the power board.

   

4. Amp on the top shelf

   Lower the amp onto the top shelf with its pins and wires going down through the slot and the green terminal facing up. Add a dab of hot glue at one corner.

   

5. Screen on the front

   First push the 4 screen posts' pegs into the 4 round holes on the front of the sled, with a drop of super glue in each hole. Then the screen: facing out, the CYD's USB-C at the bottom. Fasten with 4 × M3×6 into the posts' inserts. Run the cables around the sides through the rectangular pass-through slots.

   

6. Tidy

   Tape the wire bundles flat along the sled. Nothing should stick out past the sled's side edges, or it will catch on the rails. Leave the mic hanging free on its 18 cm wires.

How the wires run on the sled

1. Batteries in, power off

   Put both cells in now, matching the + marks. Make sure the power board is off. Once the sled is inside, you only reach the cells by sliding it out again.

2. Slide the sled in

   With both caps off, hold the tube with the window facing you. Feed the mic up through the tube ahead of the sled, then slide the sled in from the bottom, screen toward the window, its edges in the rails.

   Push until the screen is centred in the window and the power board's USB-C lines up with the hole in the back.

3. Mic into its pocket

   Reach in through the top opening. The mic pocket is the raised square on the inside of the left wall (left as you face the screen), just below the top. Drop the mic into the round pocket, flat side against the wall, sound hole over the pinhole, and add a small drop of glue at the edge. Keep glue away from the hole.

   Tube printed before Oct 18? Its pocket has a thin cover on the inside. Cut that cover away with a sharp hobby knife or flush cutters, around the inside of the square, until the round pocket is open. Don't cut through the outer wall.

4. Power button

   From outside, push the orange button's stem into the round hole in the back until it touches the switch. Press it: you should feel a click.

5. Speaker wires to the amp

   Through the top opening, put the speaker wires into the amp's green terminal: + to +, − to −. Tighten with the small screwdriver.

6. Top cap on

   Tuck the spare speaker wire around the speaker magnet. Line the cap's flats up with the screen, push it in, and twist about ⅛ turn until it stops.

7. Test

   Press the power button: the screen should start. Plug a charger into the USB-C on the back to check charging.

8. Bottom cap on

   Push it in and twist ⅛ turn. To reprogram later, turn Orbit off, twist the bottom cap off, and plug a USB-C cable up into the CYD from below.

The mic and amp share one I2S port (I2S0) in full-duplex mode, with the same clock pins and separate data pins. The mic uses the left channel (L/R tied to GND), 16 kHz or higher.