PICAXE Chip Sizes

PICAXE chips come in two series – the M2 and X2 series – and 6 physical sizes (8, 14, 18, 20, 28, 40 pin).

The M2 series chips are the standard devices allowing up to 1800 lines of BASIC code and common interfacing protocols such as RS232 (serial), infra-red and I2C. They also support parallel task processing. The X2 series have a larger memory capacity for longer programs and more variables (RAM). They also have a few more advanced interfacing protocols such as ‘1-wire’ and ‘UNIO’.

The main difference between the sizes is that there are, as you would expect, more input/output pins on the larger chips. So normally you would identify how many inputs/outputs your project requires and then select the chip accordingly.

On all M2 and X2 parts most of the pins can be user-configured to be an output, input, analogue input or touch sensor input. See the pinout diagrams for more details.

The following table gives a brief summary of the various PICAXE chips.
For a more detailed comparison please see the PICAXE manuals

The same software, BASIC language and USB download cable is shared between all the PICAXE chips.

PICAXE Chip Case Style

All PICAXE Chips are available in both Dual-In-Line (through-hole) and surface mount casing formats. The following table gives the casing styles for each size chip.

Kindly note the 28 pin format is the 300mil 'skinny DIP' format, not the wider 600 mil 28 pin format.