Hi,
There's certainly still plenty on my "ToDo" list. The PICaxe capabilities which particularly interest me are its small size and very low power consumption. Typical applications are for 24/7 "environmental" sensing (e.g. weather conditions), generally connected wirelessly and using only battery-power, or charged by very modest solar panels (e.g. cannibalised from solar garden lights).
For construction, I now often design my layouts to fit in the space of a single AA cell ! It avoids the need to devise a custom "enclosure" since the module fits directly inside the battery box, or even the battery compartment of existing equipment. In particular, an "AA PICaxe" plus a single LiFePO4 AA cell (3.2 volts) can fit in the 2 x AA battery compartment of many off-the-shelf devices.
These can be built without recourse to SMD components or even a custom PCB. A piece of Veroboard (stripboard) or "perfboard", 6 holes wide by 19 - 20 holes long is the size of an AA cell, providing the outer two tracks are slightly pared down to an overall 14 mm width. Typically, the edge tracks provide supply and ground rails, whilst the 08M2 sits in the middle of the board. Of course some track cuts and links are needed, with components standing mainly vertically, but these can be easily documented by the updated (2016) version of PEBBLE (v3.1e).
In addition to the 08M2 it's possible to fit on "dummy" battery terminals at the ends of the board and a standard PICaxe programming socket, but the "Legacy" Molex-style connector pins are more versatile and can save board space. I've fitted various other components to these boards, for example a buzzer/sounder (e.g. for low battery warning) or an RJ12 socket (common for weather station sensors) or even a second 8-pin DIL socket for an I2C EEPROM, or as a "GPIO header". Thus one of my projects still to formally document is an "AA data logger" which fits inside an AA battery compartment and can monitor/log the voltage (CALIBADCxx), current drain (through the dummy battery contacts) and temperature (CHIPTEMP) etc., for a considerable period.
Another fun project is "A weather station in an 08M2" (or two 08M2s if a wireless-link is required). Wind Speed and Rain can use simple pulse counters, with Temperature, Humidity and Barometric pressure sensors, etc. on the I2C bus (the BME280 does all these in one tiny package). Also, solar light level, charging and control can be performed with a single PV panel and one PICaxe pin. However, there are several contenders to measure wind direction; I've previously trialled both the "Rotorvane" devised by Derek Weston, and the "Ultrasonic time of Flight" method. The Rotorvane appeals because, in principle, it can measure Wind Speed
and Direction on just one PICaxe (digital input) pin.
In addition to the above, I still have plans to "finish" my code snippets for CHIPTEMP (improved READINTERNALTEMP routine) and the BME280 (humidity sensing). Also, a Sun Position calculator (to complement the Sunrise/Sunset program) and an "08M2-powered AXE133" (to drive the LCD/OLED displays which already have an I2C "backpack" fitted). Not to mention the "Lithium AA cell on wheels" line-follower (using dual acceleration-controlled miniature steppers), and several other projects.
Cheers, Alan.