This is a kit for a Rev.4 AVR VUSB Board

(http://matrixstorm.com/avr/tinyusbboard/).

Some will perhaps already know the link (http://matrixstorm.com/avr/tinyusbboard/) and / or know my project otherwise.

As previously announced revision 4 of my projectis is in development now - this time connected with a switch from through-hole technology (THT) to surface-mounting technology (SMT). The board looks prettier than rev.3 and is faster to build It is also cheaper, more robust and might be useful in other (kickstarter?-)projects as the center logic board.

The layout allows using solder bridges on the back of the wiring, in order to route the USB PINs PD2 and PD7 to the outside pin header. The connection to the USB Vcc is separable (interrupt "FUSE" solder bridge), so that even a self-supply with other voltages is conceivable.

The microcontroller is (pre-)programmed with the new firmware selftest firmware, already.

The kit contains:

1x tinyUSBboard rev.4 PCB (about 2.5cm x 5.0cm)

1x preprogrammed (and "prefused") ATmega8-16AU or ATmega8A-AU
1x MLCC 22uF

2x resistor 10kOhm
6x resistor 1kOhm
2x resistor 68Ohm
2x ZMM3v6 zener diode 3.6V

2x ceramic capacitor 1uF
2x ceramic capacitor 18pF

2x button (in SMT 3mm x 6mm x 2.5mm)
1x crystal 16MHz

1x LED green
4x LED red

Components, which are hard to distinguish have a color marking (and an accompanying list). No solder, nor flux is included.

An english description of the final board can be obtained from the webpage: http://matrixstorm.com/avr/tinyusbboard/

I am happy to answer questions or to tell additional details (write me just via tindie or by email). (But because I sell as a private person this is not mandatory.) Furthermore, I assume no warranty, exchange, liability or the like. Pictures are similar.

Details

TinyUSBboard is an Arduino compatible, minimalistic and cheap AVR microprocessor board with USB interface and simple "do it yourself" capability. It utilizes directly features of USB without FTDI chip and/or any USB to serial converter. It can be programmed via assembler, C, Arduino or of course BASCOM. All its components you need to construct it are universal and available nearly everywhere - no special PCB needed. It is well suited for beginners to learn AVR microcontroller programming and/or it can be used on solderless breadboards very simple to do various projects. For example using some firmware provided on this site turns it into a programming hardware for blank AVR microcontrollers, which can be used to produce further tinyUSBboards for family members, friends or collegues...

While normal handling with microcontrolling units (MCUs) needs additional equipment, tinyUSBboard only needs a Mac-, Windows- or Linux computer with a single free USB socket.

The board in form of a regular stick (approx. 2.5cm x 8.0cm) uses an ATmega8-16PU MCU, clocked at 16MHz. This IC allows up to 8kib of programmed code within its flash-memory. It also has additional 512byte persistent electronical eraseable memory (EEPROM) and 1kib volatile memory RAM. (For further features see its datasheet in the datasheet-section).

Three of the MCUs pins (PIN2, PIN12 and PIN13) are actually used for the USB interface. This feature and using the latest, preflashed bootloader "USBaspLoader" (https://github.com/baerwolf/USBaspLoader) allows convenient and fast programming via USB, again and again: Just press (keep pressed) the program-button and reset (or powerup) the stick. The bootloader, emulating an usbasp-programming hardware, will take over and allows (re)programming the MCU. (Once started, of course, the prog-button can be released. Any repeated press (or "reset") then will exit the bootloader.)

Furthermore, there are five LEDs on the board. One LED indicates the power supply via USB. The other four (red) LEDs are connected to and can be controlled via the IO of the microcontroller (PB0, PB1, PD3 and PD5). If in any circumstances only the direct contacts of the controller are required, LEDs can be disconnected permanently. The bootloader occupies 2 of the 8 kib of flash memory.

Althought there are lots of AVR boards available, tinyUSBboard has because of its special design and the complete revised sourcecode of USBaspLoader some unique advantages against other AVR VUSB boards. A list with the most outstanding ones is collected here.

Hardware advantages:

cheap and simple thanks to universal components (veroboard - no special PCB needed)
very compact because of USB-stick form factor
very fast datatransfers (no need for slow serial programming)
klick-based bootloader condition (no jumper required)
helps to conserve flash lifetime (interrupt trampolines combined with no complete chip-erase necessary)
nearly all PINs are routed (for use on breadboards)
USB-powered - no extra powersource needed
do-it-yourself enabled

Software advantages:

completly revised USBaspLoader
lots of space optimizations
bootloader section update-/exchangeable without any further programming device needed

no hardware locking needed

lots of new features (bootloader update feature, software lockbits, exit-logic, accepts ISP-clock commands, able to read its fuses/lockbits, fully supported flash-read, "magic values" to distinguisch different hardware-layouts, etc...)