OTTO-project

Hardware prototype for the OTTO Synthesizer by Topisani

10x10 silicone buttons with led backlight

Main features

Mainboard

• ILI9341 based TFT 2.8" TFT screen.
• 4 low profile clickable encoders
• 40 function keys
• STM32F103VET6 mcu
• Raspberry GPIO connector
• connects to all the various boards
• expansion headers

Power board

• 2A 5-16V DC input & 500mah micro usb input
• MAX8903A 1s Lipo charger IC with path management
• 5V 2A DC-DC boost converter (TPS61090) & 3V3 700mah LDO (XC6210)
• MAX17048 1s lipo fuel gauge, connected via i2c to the raspberry
• pi_power circuit for monitoring and control boot and shutdown routine

Audio Board

• SGTL5000 Audio Codec
• Electret microphone amp circuit
• LM4860 speaker amplifier
• 1 TRS jack line IN
• 1 TRS jack line OUT
• 1 Headphone IN

Keyboard

• 2 octaves keyboard with 16 keys bottom row
• expansion headers
• 16 addressable rgb leds

those specs refer to the tactile buttons version, but a led backlight button version is in the works too.

one of the first design iteration