Brake / Coast: any difference this year?

[Gary Dillard]

Since the driving requirement is a little different this year, I just wondered if anyone was experimenting with brake vs coast jumper settings on the Victors to see if one or the other makes it easier to control making the turn in high gear.

[The Lucas]

The brake/coast only affects the Victor 884 when it is in neutral (127) so it shouldn't matter for your high speed turn (unless you want to put the left motors in neutral). We use digital outputs on the brake/coast header so we can select between the modes. The autonomous programmers like Brake mode (more precision) and the drivers like Coast mode (smoother). However, last year's driver liked Brake mode for maneuvering around The Rack. This year's driver will probably go back to Coast mode. Abrupt stops could be dangerous in this game.

[Doug Leppard]

I was thinking of having brakes this year for hybrid mode. If it coasts and I am going around a corner when power goes out it might keep going straight into the wall or crash into another robot. Sure you might coast across another line and get 4 more points but I think there is more chance of crashing.

[Richard McClellan]

How did you connect the brake/coast header to a digital output port? Did you just take a standard PWM cable, plug it in, and then send it a 1 or 0 for brake or coast?

[bear24rw]

Just connect a digital output to the center pin on the brake/coast header, i think if i remember corrently that 0 is break and 1 is coast, also if no signal is givin (as in the cable fell out) it defaults to brake

[Urban Hawk]

you could always try to set it up so you can switch between the two modes.

[robbrad]

With our drive base going 12 feet per second on mecanum wheels, we prefer BRAKE and leave it as such. Keep in mind the traffic we will most likely encounter and the importance of manuverability to get around said traffic. We can't have our robot coasting and sliding into everything at 12 fps.

[The Lucas]

Originally Posted by richardmcc2

How did you connect the brake/coast header to a digital output port? Did you just take a standard PWM cable, plug it in, and then send it a 1 or 0 for brake or coast?

My team makes its own PWM cables, so I just take a 24 gauge white wire and crimp a female terminal onto each end. One end I insert into a housing and plug into the the digital output. I shriktube the other end (to prevent shorts) and plug into the middle pin of the brake/coast header. I make sure to tie wrap it down near the speed controller so the terminal doesnt get knocked off the header.

If you dont make your own cables, you may have to cut the male ends off of 2 PWM cables and solder them together. Then take the white pin out of one housing, shrinktube it and connect it to the middle pin of the brake/coast header. Unfortunately, each of these cables costs you about $10 and is plenty of work to make.