Hardware

There are a few key features of The Glitch hardware.

• Small size
• Atmel 8-bit processor
• USB connector
• Micro SD reader
• DIP switch
• Solderless pinouts
• USB solder pads
• Programmable LEDs

Revision

The Glitch hardware may change over time. This section documents components of the different revisions of The Glitch.

r16

First hardware release.

Processor

The Atmel AT90USB1287 processor is the core of The Glitch.

Flash Memory	128K
RAM	8K
EEPROM	4K

For more information on this chip see the Atmel documentation.

USB

The Micro USB socket is used for connecting The Glitch to a host device through a USB cable. USB can also be used to for power only.

USB Pads

As an alternative to the Micro USB connector, there are four solder pads which connect to the four USB lines (GND, D+, D-, +5v). The common convention for USB wire color is Black (GND), Green (D+), White (D-), and Red (+5).

For a reference on using the see Alternate USB Wiring

Note:

DO NOT use the Micro USB plug and the USB Pad simultaneously. Use either the Micro USB plug OR the USB Pad. Using both USB connections can cause damage to The Glitch.

Micro SD

The Glitch is able to read and write to Micro SD cards. The Micro SD card reader is spring loaded. Push in the Micro SD card once to loader it. Push the Micro SD card in a a second time for the spring to release the card.

Note:

Do not pull the Micro SD card out without pushing to spring release.

The Glitch converts from 5v to 3.3v for the SPI pins connected to the Micro SD card using a voltage regulator and line buffer.

DIP Switch

The DIP switch has five switches all together. These are ON/OFF switches which allow for user input.

(The following assumes using negative logic.)

• ON - Current can pass through. (The switch is positioned closer to the Micro SD reader.)
  
• OFF - No current can pass through. (The switch is positioned closer to the female Header socket.)

Reset Button

The Reset button is used to set the bootloader to a state where it is ready to accept new firmware.

LEDs

Three programmable LEDs are mounted on the top. The LEDs are green, yellow, and red. Each is pulled high with a 10K oHm resistor.

Header PINs

The back of The Glitch has 14 PIN sockets.

PIN Reference

Note:

The Top is the side with the Micro USB connector.

PIN	PIN #	I/O	Description
+5v			+5 volts output. It can also accept +5v input.
GND			Grounding to the board.
RST			When pulled to ground the RST pin will reset the bootloader.
SCL	0	Digital	Used for I2C.
SDA	1	Digital	Used for I2C.
RX	2	Digital	Used for UART.
TX	3	Digital	Used for UART.
ICP	4	Digital
SLCK	21	Digital	Used for SPI.
MOSI	22	Digital	Used for SPI.
MISO	23	Digital	Used for SPI.
ADC0	38	Analog
ADC1	39	Analog

SPI

The MISO, MOSI, SCLK, and one other digital pin (RX, TX, SDA, or SCL) can be used for CS in order to communicate over SPI.

UART

The RX and TX pins can be used to communicate over UART.

I2C

The SDA and SCL can be used to communicate over I2C.