Serial port AVR programmer
I’m still testing the newest USBmicro firmware. Meanwhile I thought I would document a little serial port to AVR programmer I made. The design is from a schematic on the Internet. Obviously the design was by Olimex. Note that the simple programmers of this type only work with a laptop or PC with a “real” serial port – a USB-to-serial does not work.
This is the schematic. Ignore the 10-pin header on the right. You will want to replace it with the 6 pin header.
This is the top of the board:
These are the parts:
These are the part locations:
Yellow arrow – R1
Green arrow – R2
Violet arrow – R4
Red arrow – R5
Blue arrow – R3
Diodes. Note their orientation. The band on the diode has to be in the circuit as shown:
Red arrow – Z1
Green arrow – Z2
Yellow arrow – D1
6 pin connector:
Green arrow – MISO, Pin 1
White arrow – SCK
Yellow arrow – Reset
Red Arrow – 5V from target
Blue arrow – MOSI
Black arrow – ground
This highlighted path shows all of the ground connections. Note it goes under the transistor base lead:
That is a path of solder from pins 6 and 7 of the Dsub-9 connector to R1:
The highlighted is the connections to 5V:
This shows the base lead going over, but not touching ground, and connecting to R5 and D1:
This is pin 1 of the Dsub-9 connector:
On the 10 pin connector, pin 1 is MOSI, 5 is Reset, 7 is SCK, 9 is MISO, and 2 is 5V.
They need to be connected differently when connected to the 6 pin connector.
If you copy this exactly, counting holes and placing the components in the very same locations, you should be able to get this circuit working.
