Creative Commons images are CC BY-NC-SA 3.0

Retired RETIRED

This product has been retired from our catalog and is no longer for sale.

This page is made available for those looking for datasheets and the simply curious. Please refer to the description to see if a replacement part is available.

Replacement: None. We are no longer carrying this development board but have a look at the rest of our development tools. This page is for reference only.

Description: A custom header board for ATMega128 AVR microcontroller with filtering capacitors, 10 pin STK ICSP port, 10 pin JTAG port, and extension ports to every pin. Comes fully assembled and tested.

  • FR-4, 1.5 mm (0.062"), green solder mask, white silkscreen component print
  • ICSP 5x2 pin connector for in-circuit programming with AVR-PG1B or AVR-PG2B
  • JTAG 5x2 pin connector for in-circuit debugging with AVR-JTAG
  • 16MHz oscillator circuit
  • 32.768 kHz oscillator circuit
  • ATMega128 AVR microcontroller
  • Reset IC ZM33064
  • +5V voltage regulator LM78L05
  • Power supply filtering capacitors
  • Digital-Analog GND jumper
  • Digital-Analog VCC jumper
  • Extension pin headers for each uC pin

Dimensions: 47x47 mm (1.85x1.85")
Documents: avr-h128b.pdf, Schematic, AVR ICSP connector

Comments 3 comments

  • This is a great breakout board but has a very cheap and insufficient parts; namely the voltage regulator and low voltage detector. The Atmega128 can draw up to 400mA of current but the voltage regulator on the board is a 78L05 (which only delivers 100mA). The low voltage detector is tied to the /reset pin the uController but the voltage detector’s trip point is MUCH to high (4.7-4.85) for battery power (especially if the regulator is only dilivering 100mA).
    I found the following to fix the problem quite nicely:
    1)Either replace the low voltage detector with one at a lower trip point or just rip it off completely (alot of people wont need it if they replace the voltage regulator).
    2)Replace the 78L05 with at the very least a 7805(DOV 2v, 1A) but there are nicer regulators out there for 1$.
    Two suggestions:
    a)LT1129-5 @ 700mA with DOV of 0.4V. This chip has many protections including reverse polarity, current, temp, etc
    b)TL750M05 @ 750mA with DOV of 0.6V. Same protections as the other but also Voltage Load Dump which is good to have with motors
    A second note is to make sure that the regulator is giving you 5V. Some 5v regulators give 5.5v which the Atmega128 will happily accept but some programmers (that take power from the board) will not be very happy.

  • Bought one recently and had to debug the ADC. After two lost hours I found that pin 62 (AREF) had a solder bridge to pin 63 (GND). After I cleaned up the solder bridge everything was good to go. I don’t blame SparkFun for this, as it’s an Olimex product, but if you’re having issues check for bridges.

  • After contacting SparkFun and Olimex we determined that this header board contains the ATMega128-16AU part and not the ATMega128-16AC part as shown in the picture. This is very good news since the 16AU is industrial temperature range instead of commercial temperature range.


Related Products