Long push (> 1 second: keep the button switch pushed down until something happens on the screen)
Short push (<1 second: push and release the button switch
AVR Oscilloscope Clock Instructions (for a Tektronix 400 series scope):
The clock requires 5V power on the 2 prong header, + and - are marked, though somewhat obscured by the header. The +(positive) is on the side of the RS232 header, the –(negative) is next to the RTC crystal. You can make a cable using the supplied 2-pin female connector (officially called "terminal housing"). The –(negative) side is marked as a ‘1’ on the female connector itself, though the marking is very small. This connector is polarized so reversing the power when using this connector is not possible (provided the cable is constructed properly)
Connect the 10x probes to the terminals marked 1 and 2. Set the scope in X-Y mode and connect the probes to channels 1 and 2. Set both channels to DC mode and the voltage range to 0.5V per division. You can tweak the display size by using 0.2V per division and manually reducing the voltage per division value (VAR knob). See the FAQ for a possible hardware modification to change the voltage range and improve the appearance of the clock.
Most scopes define CH1 and the X axis and CH2 as the Y axis. Some, for example the Tektronix 485, reverse this convention. Please swap the probes in that case.
Control of the clock is primarily done using the on-board push button switch. This push button switch has 2 actions:
|
Long push (> 1 second: keep the button switch pushed down until something happens on the screen) |
|
Short push (<1 second: push and release the button switch |
The long push enters the Time/Date Set mode, the short push enters the Menu mode.
Time/Date Set mode:
|
short push advances the current field one |
|
long push moves
to the next field. |
Menu mode:
|
short push selects the next value (or activates the current option) |
|
long push moves to the next option. |
Changing the time on the AVR Clock using the
push button switch:
To change the time, make sure that the Numeric Display does NOT show the
current date. If so, change it using the menu. A long push will enter the Change mode.
If the Numeric Display is Off, the time will also be changed, even if the Binary
Clock Display is active. The clock is stopped
when changing time. The value being changed will flash at this point. If the
Numeric Display is Off, one of the Clock Hands will flash in an Analog Dial
Display. In a Binary Clock Display, the "lights" columns representing the value
being changed will flash. A short push will increment the
current field (hours, minutes, seconds). A long push will move to the next
field, using the current field value as the new time value. Once done with the
seconds field, a "Push To Start" message pops up. A short push will restart the
clock at the selected time. However a long push will restart the clock at the
actual time, as kept by the on-board Real Time Clock. This is handy if you
entered the Change mode by accident or if you changed your mind. Change mode
times out after 30 seconds of inactivity.
Changing the date on the AVR Clock using the
push button switch:
To change the Date, make sure that the Numeric Display shows the current
date. If not, change it to display the Date using the menu (Menu-Num:Date). A long push will enter the Change mode.
The value being changed will flash. A short push will increment the current
field (year, month, day). A long push will move to the next field. The clock
leaves Change mode automatically after finishing the Day value.
The order of change is Year, Month, Day. This way, the
clock can verify the date validity better (number of days per month, leap years
etc.) Change
mode times out after 30 seconds of inactivity.
Options available on the on-screen menu:
|
Option |
Values |
Function |
Option |
Value |
Function |
|
Num |
12hr |
Select Numeric Field to Display |
Dial |
12hr |
Select Clock Dial to Display |
|
GPS |
Off |
Select GPS NMEA input using the selected local time zone offset |
DST |
USA |
Select Automatic |
|
Boot |
Reboots the clock |
Demo |
enter DEMO mode |
||
|
Chrono |
Off |
fractional seconds |
Cal |
Off |
Turn Calibration Screen On and Off |
|
Led |
On |
Controls on-board Led |
BurnIn |
On |
Turn BurnIn Prevention Off and On |
|
Play |
Off |
Fun modes: Reverse, Fast Forward and Fast Reverse |
Reset |
Off |
Re-initialize the EEProm area of the Atmega168 to "virgin" state. |
|
Name |
On
|
User Name Display |
Current User Name is displayed below the Menu |
Changing an option
on the AVR Clock using the button switch:
A short push will enter the Menu Mode. The option being updated/selected is
flashing. Move to the next option by a long push. The options Boot
and Demo are
activation options. A short push will activate them. The other options are
selection values. A short push will show the next selection value. Moving to the next option
(using a long push) when the selection value has changed, will activate the
selected value
and the clock will leave the menu mode.
Optional RS-232 serial interface:
The clock can also also be
operated through the RS-232 serial port, using a PC (or any other terminal device),
though this interface may be removed in the future. To do this, you will need a cable consisting of a female DB-9 connector
(for most PCs) and the 3 pin connector included with the AVR clock. Wiring is
as
follows
3-pin connector - 1:GND, 2:out/RXpc, 3:in/TXpc.
DB-9 connector - 5:GND, 2:RX, 3:TX.
The clock is set for a baudrate of 19,200. You can use the HyperTerminal program included with Windows, or use a freeware program like Bray's Terminal, which can be also downloaded from this page.
Once the cable is connected properly, the clock will display a sign-on message on the terminal when it powers up. The command 'X' is used to get the clock's attention (interactive mode). A prompt will show:
Command(B,C,D,F,G,H,K,L,M,N,P,R,S,T,U,V):
B: Toggle Burn-in Prevention
C: Toggle Calibration Output
D: Set Date
F: Set Clock Face Mode
G: Toggle GPS NMEA input Parsing
H: Show extended Help
K: Toggle the Fractional Seconds Display
L: Toggle LED Blinking
M: Toggle 1PPS Trigger Mode
N: Set Numeric Display Mode
P: Set Clock Play Mode
R: Reset the EEProm Configuration Data
S: Show Status info
T: Set Time
U: Set Automatic Daylight Saving Time Adjustment
V: Toggle Verbose Output
Execution of any of these commands, or another 'X' will end the interactive mode. Note that the commands can be given in either upper or lower case.
The AVR clock FAQ provides much more information on how to use the clock and currently serves as the manual.