28X2 (December 2010)
The original 28X2 parts were based upon the PIC18F2520 microcontroller. As this was a 5V only part, a special 3V
variant called the 28X2-3V was also produced, based upon the 3V equivalent microcontroller, the PIC18F25K20. A new upgraded version of this microcontroller, the PIC18F25K22, has now been released. This is an enhanced
version microcontroller that has several advantages over the previous two parts:
- Full 2.1 to 5.5V operating range in one chip, meaning no need for separate 3V and 5V parts
- Increased optional clock speed, 64MHz external, 16MHz internal (default is still 8MHz internal)
- Many additional ADC channels, with individual ADC pin masking
- New support for touch sensors on all ADC channels
- Added support for RFIN and RFOUT commands for Manchester encoded radio communication
- New HPWM module with power steering
- Two additional PWM channels with separate timers (so now 4 PWM channels available on 28pin parts)
- New SR latch, voltage reference and DAC output modules
Therefore the 28X2 firmware has now been migrated to the new 18F25K22 part, with the original 2 parts superseded.
Within the PICAXE manuals the parts are now referred to with the following names (28X2, 28X2-5V or 28X2-3V):