[archiver]

Posted by Nate Smith.

Other on team #66, GM Powertrain/Ypsilanti HS/Willow Run HS, from Eastern Michigan University and GM Powertrain.

Posted on 1/23/2000 11:49 AM MST


In Reply to: Programing help... posted by Adam Anderson on 1/22/2000 2:07 PM MST:



Adam,
One possibility is the packet_num variable that you can retrieve from the Master uP in the robot controller. From my work with the dashboard port spec, which also uses this packet number, I can tell you that the number changes roughly 40 times a second. So, if you wanted to, for example, have a motor run for roughly six seconds, you could use code similar to this(using sample variables of course):
--------START PBASIC CODE---------
'Start Motor
if p3_sw_trig = 1 goto startmotor
goto skipstart
startmotor:
startpacket = packet_num
endpacket = packetnum + 240 '6sec x 40cyc/sec = 240
motorrunning = 1
relay3_fwd = 1
skipstart:
if motorrunning = 1 goto checkmotor
goto skipcheck
checkmotor:
if endpacket >= packet_num goto stopmotor
goto skipstop
stopmotor:
relay3_fwd = 0
motorrunning = 0
goto skipcheck
skipstop:
motorrunning = 1
relay3_fwd = 1
skipcheck:
---------END PBASIC CODE-----------
Note that you would have to declare motorrunning, startpacket, and endpacket at the top of your program, as well as uncomment the packet_num declaration and set c_packet_num equal to 1 in the DEFINE CONSTANTS FOR INITIALIZATION section. This code also only works for times up to roughly 6 seconds, after which the endpacket calculation would roll over 255 and the program would reach the desired packet number before the desired time frame is reached. Hope this helps...

Nate Smith