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T8-Sequencer

lluisestape-upc·T8-Sequencer

T8-Sequencer PCB layout, top view — open source ESP32 board by lluisestape-upc
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About the T8-Sequencer PCB

T8-Sequencer is an open source ESP32 PCB design by lluisestape-upc, published on GitHub under the MIT license. It is a 2-layer board measuring 290 × 210 mm, with 96 components from 40 distinct parts.

Its main chip is the ESP32-WROOM-32, from the ESP32 family. Other key parts include the ST7789 2.4in modulo, CD74HC4067M, AMS1117-3.3, CH340C and MCP23017x-x-SP. By type, the board carries 24 switches, 17 diodes, 17 resistors, 13 capacitors, 11 ICs and 2 transistors.

It belongs with the audio, displays & leds and usb & debug tools designs in this gallery.

From the project

16-step ESP32 groovebox: two-layer 290x210 mm KiCad board, DRC-clean and fabrication-ready, with the Python scripts that generated and repaired it

A 16-step hardware groovebox built around an ESP32-WROOM-32, designed from scratch in KiCad 10. Two copper layers, 290 × 210 mm, DRC-clean and fabrication-ready.

A desktop groovebox in the spirit of the Roland T-8: sixteen step buttons with per-step RGB feedback, ten pots for live parameter control, a rotary encoder for menu navigation, a 2.4" colour display, MIDI in and out over TRS-A, and two independent audio outputs — a line-level I²S DAC and a class-D amplifier for a small onboard speaker. The whole thing is powered and programmed over a single USB-C connector.

T8-Sequencer, from the project README
From the project README

Main components on the T8-Sequencer

ESP32-WROOM-32ST7789 2.4in moduloCD74HC4067MAMS1117-3.3CH340CMCP23017x-x-SP6N138MAX98357A (modulo)MCP23017 0x2174AHCT1G125

T8-Sequencer bill of materials (BOM)

96 components, 40 distinct parts.

QtyPartRefs
1
ESP32-WROOM-32
U1
1
~
U2
1
ST7789 2.4in modulo
U3
1
CD74HC4067M
U4
1
AMS1117-3.3
U5
1
CH340C
U6
1
MCP23017x-x-SP
U7
1
6N138
U8
1
MAX98357A (modulo)
U9
1
MCP23017 0x21
U10
1
74AHCT1G125
U11
2
Q_NPN_BCE
Q1, Q2
1
USB_C_Receptacle_USB2.0_14P
J1
1
RotaryEncoder_Switch
RE1
10
10k
RV1, RV2, RV3, RV4, RV5, RV6, RV7, RV8 +2
16
SW_Push
SW1, SW2, SW3, SW4, SW5, SW6, SW7, SW8 +8
1
BTN_PLAY
SW17
1
BTN_REC
SW18
1
BTN_SHIFT
SW19
1
BTN_PATT
SW20
Show 20 more
QtyPartRefs
1
BTN_TEMPO
SW21
1
BTN_CLEAR
SW22
1
BTN_F1
SW23
1
BTN_F2
SW24
16
WS2812B
D1, D2, D3, D4, D5, D6, D7, D8 +8
1
1N4148
D13
1
C
C1
1
C_Polarized
C2
8
100nF
C20, C21, C22, C23, C24, C27, C29, C30
3
10µF
C25, C26, C28
2
5.1kΩ
R1, R2
5
10kΩ
R3, R4, R20, R21, R22
1
470Ω
R5
1
1kΩ
R6
3
4.7kΩ
R7, R23, R24
1
33Ω
R8
1
10Ω
R9
1
220
R10
1
10k
R25
1
2.7k
R26

T8-Sequencer design files

The KiCad project lives in the lluisestape-upc/T8-Sequencer repository on GitHub; these links point at the commit this page was built from.

T8-Sequencer: common questions

What microcontroller does the T8-Sequencer use?

The T8-Sequencer is built around the ESP32-WROOM-32, from the ESP32 family.

How big is the T8-Sequencer PCB?

The T8-Sequencer measures 290 × 210 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the T8-Sequencer?

96 components, from 40 distinct parts. The full bill of materials is listed on this page.

Where can I download the T8-Sequencer design files?

From the lluisestape-upc/T8-Sequencer repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the T8-Sequencer design in my own project?

Yes, under the terms of its MIT license, which lluisestape-upc chose for the repository.

Can I test firmware for the T8-Sequencer without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug ESP32 firmware against it before you order a PCB.

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