Here is a brief comparison between the two:
- DWex is based on ATmega328 running at 8MHz (as opposed to 16MHz); that should make it take less juice out of the 3V coin battery;
- DWex has only one button (as opposed to 3); and even that could be eliminated eventually (replaced with a tilt switch, for example);
- DWex has 4 fewer LEDs; the way to show the time (software) does not require the extra 4 LEDs of Makerbot watch;
- DWex spends most of its time in sleep mode (I don't know how Makerbot watch works though, to be honest, but I think time is kept by the ATmega chip itself; therefore, no sleep for it); it only wakes up when the button is pressed, to show the time;
- DWex is thinner, and that may be due to the much bigger crystal used by Makerbot;
- DWex does not have a buzzer;
- Like Makerbot watch, DWex has both the ICSP and FTDI connectors on board, making it an "Arduino environment on your wrist" as well.
- They both cost the same, US$30 (plus $3 regular shipping to North America). DWex is in stock though. It is real and working.
Some of the features of DWex are:
- time is shown by lighting/flickering only two LEDs, for hours and minutes;
- time can be set by the user through the button, without connecting the board to the PC;
- consumption is 12mA when the time is shown, 120uA when asleep; the CR2032 coin battery should last at least a few months;
- can be re-programmed to make use of the alarms of on-board DS1337 RTC (this functionality is not implemented, but the hardware capabilities are in place).