24
24
/******************************************************************************
26
For a schematic, see propeller-clock.sch.
30
- a PC fan is wired up to the 12V supply.
32
- the fan's SENSE (tachiometer) pin is connected to pin 2 on the
35
- the pins 4 to 13 on the arduino should directly drive an LED (the
36
LED on pin 4 is in the centre of the clock face and the LED on pin
39
- if a longer hand (and a larger clock face) is desired, pin 4 can
40
be used to indirectly drive (via a MOSFET) multiple LEDs which
41
turn on and off in unison in the centre of the clock.
43
- a button should be attached to pin 3 that grounds it when pressed.
45
Implementation details:
47
- the timing of the drawing of the clock face is recalculated with
48
every rotation of the propeller (for maximum update speed).
50
- pressing the button cycles between display modes
52
- holding down the button for 2 seconds enters "set time" mode. In
53
this mode, the fan must be held still and the LEDs will indicate
54
what number is being entered for each time digit. Pressing the
55
button increments the current digit. Holding it down moves to the
56
next digit (or leaves "set time" mode when there are no more). In
57
order, the digits (with accepted values) are: hours-tens (0 to 2),
58
hours-ones (0 to 9), minutes-tens (0 to 5), minutes-ones (0 to 9).
28
* a PC fan is wired up to a 12V power supply
30
* the fan's SENSE (tachiometer) pin connected to pin 2 on the
33
* the pins 4 to 13 on the arduino should directly drive an LED (the
34
LED on pin 4 is in the centre of the clock face and the LED on pin
37
* if a longer hand (and a larger clock face) is desired, pin 4 can be
38
used to indirectly drive (via a MOSFET) multiple LEDs which turn on
39
and off in unison in the centre of the clock.
41
* a button should be attached to pin 3 that grounds it when pressed.
43
Implementation details:
45
* for a schematic, see project/propeller-clock.sch.
47
* the timing of the drawing of the clock face is recalculated with
48
every rotation of the propeller.
50
* a PC fan actually sends 2 tachiometer pulses per revolution, so the
51
software skips every other one. This means that the clock may
52
appear upside-down if started with the propeller in the wrong
53
position. You will need to experiment to dicsover the position that
54
the propeller must be in when starting the clock.
58
* pressing the button cycles between variations of the current
61
* pressing and holding the button for a second cycles between display
62
modes (e.g., analogue and digital).
64
* pressing and holding the button for 5 seconds enters "time set"
65
mode. In this mode, the following applies:
66
- the field that is being set flashes
67
- pressing the button increments the field currently being set
68
- pressing and holding the button for a second cycles through the
69
fields that can be set
70
- press and holding the button for 5 seconds to finish
60
72
******************************************************************************/