Technical datasheet

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info@bareconductive.com

PRODUCT DESCRIPTION

The Touch Board is a microcontroller board with dedicated capacitive touch and MP3

decoder ICs. It has a headphone socket and micro SD card holder (for le storage), as well

as having 12 capacitive touch electrodes. It is based around the ATmega32U4 and runs

at 16MHz from 5V. It has a micro USB connector, a JST connector for an external lithium

polymer (LiPo) cell, a power switch and a reset button.

It is similar to the Arduino Leonardo board and can be programmed using the Arduino

IDE. The ATmega32U4 can appear to a connected computer as a mouse or a keyboard,

(HID) serial port (CDC) or USB MIDI device.

SUMMARY

• Microcontroller Microchip ATmega32U4

• Touch IC Resurgent Semiconductor MPR121

• MP3 decoder IC VLSI Solution VS1053b

• Audio output 15mW into 32Ω via 3.5mm stereo socket

• Removable storage Up to 32GB via micro SD card

• Input voltage 3.0V DC – 5.5V DC

• Operating voltage 5V DC

• Max. output current (5V rail) 400mA (100mA at startup)

• Max. output current (3.3V rail) 300mA

• LiPo cell connector 2-way JST PH series - pin 1 +ve, pin 2 -ve

• LiPo charge current 200mA

• Capacitive touch electrodes 12 (of which 8 can be congured as digital I/O)

• Digital I/O Pins 20 (of which 3 are used for the MPR121 and 5 are used for

the VS1053b — the latter can be unlinked via solder blobs)

• PWM channels 7 (shared with digital I/O pins)

• Analogue input channels 12 (shared with digital I/O pins)

• Flash memory 32 kB (ATmega32U4) of which 4kB used by bootloader

• SRAM 2.5kB (ATmega32U4)

• EEPROM 1kB (ATmega32U4)

• Clock speed 16MHz (ATmega32U4), 12.288MHz (VS1053b)

• DC current per I/O pin 40mA sink and source (ATmega32U4), 12mA source / 1.2mA sink (MPR121)

• Analogue input resistance 100MΩ typical (ATmega32U4)

Technical Data Sheet

Touch Board

PAGE 1
Touch Board ® Technical Data Sheet PRODUCT DESCRIPTION Touch Board is a microcontroller board with dedicated capacitive touch and MP3 decoder ICs. It has a headphone socket and micro SD card holder (for file storage), as well as having 12 capacitive touch electrodes. It is based around the ATmega32U4 and runs at 16MHz from 5V. It has a micro USB connector, a JST connector for an external lithium polymer (LiPo) cell, a power switch and a reset button.
PAGE 2
POWER The Touch Board can be powered via the micro USB connection or from a 3.7V lithium polymer (LiPo) cell connected to the 2-way JST PH series connector. The power switch will switch the board on or off when powered by either power source. If power is supplied over USB whilst the LiPo cell is connected, then the charge LED will illuminate and the LiPo will charge from USB power, regardless of power switch position.
PAGE 3
• PWM Pins 3, 5, 6, 9, 10, 11, and 13 Provide 8-bit PWM output. • SPI Note that the SPI pins are not connected to any of the digital I/O pins as they are On the ICSP header on the Arduino Uno. This means that if you have a shield that uses SPI, but does NOT have a 6-pin ICSP connector that connects to the Touch Board’s 6-pin ICSP header, the shield will not work. • LED There is a built-in LED connected to digital pin 13.