This is a list of serial port programmers for AVR microcontrollers. There is really no
difference in performance between any of these devices. They are slower than the parallel port programmers,
and are slightly more difficult to make, due to the level shifting required to go from RS232 to TTL levels.
They differ in serial port pins used for the SPI signals, and the use of inverters on some lines. The
advantage to these over the parallel port programmers is simply that some motherboards which lack parallel
ports still have serial ports.
This is the original DASA programmer. There are probably more of these out there than any other, even though
they are more complicated (expensive) than their parallel port counterparts. About every software package supports
this programmer.
This programmer is sometimes referred to by the name "DASA-2", and I will call it that, but it is not a very
common programmer. It has the added complexity of a transistor inverter on the reset line. It works, but no
better than the DASA-1 above.
This programmer is very similar to the DASA-2, above, but has a slightly different wiring diagram. It is much
more popular, and is known widely as "DASA-3".
This is a smart programmer using an ATmega with a TTL level serial input and an ISP output. The TTL serial would
come from any of the RS232 to TTL converters, or a USB to TTL cable. The serial connector is pinned out to hook
to an FTDI USB to TTL cable.
