Asked — Edited

H Bridge Movement

Hi All.

How do I move a robot forward a certain distance (or time, since distances are going to depend on wheel size), then stop? I couldn't see an obvious way from the H bridge control panel.

thanks in advance,

Frank


ARC Pro

Upgrade to ARC Pro

ARC Pro will give you immediate updates and new features needed to unleash your robot's potential!

United Kingdom
#1  

You'll need to use an EZ-Script and calculate how long it takes to move a certain distance. I'm not too clued up on EZ-Script yet and not home so can't check but full help is available in the EZ-Script module.

United Kingdom
#2  

I just had a play with EZ-Script (until ARC played up and froze... it's still frozen now 10 minutes on).

Basically, write an ez-script.

From here on out it is assumed movement at full speed

Work out how far your robot travels in 1 second, easy way is to use EZ-Script to do this...

Place your robot down, mark where it starts. Write an EZ-Script containing this;

Forward(255,1000)

Run the code. Mark where the robot ends up. Measure the distance between. Divide the distance by 1000 to get distance per millisecond (makes it easier in EZ-Script).

I.e. Robot moved 300mm when running the script. So the speed is 300/1000=0.3mm/ms

The calculation to work everything here on out is simple; t=d*s where t=time in milliseconds, d=distance in mm and s=speed in mm per millisecond.

Now, work out how long it will take to move the robot your desired distance. Let's say we want it to move 1 meter (or 1000mm).

Distance/Speed = time 1000/0.3 = 3333

To set up ARC to move by 1 meter write the following EZ-Script

Forward(255,3333)

When you run that script the robot will move forward 1 meter.

To move it by 600mm you would jut work out 600/0.3 = 2000 so the code would be;

Forward(255,2000)

If it moved 200mm after running the first script your speed would be adjusted to 0.2mm/ms and therefore your calculation would be distance/0.2 (so for 1m movement it would be 1000/0.2 = 5000)

You will need to determine your robots speed as this will vary between robots.

It's simple mathematics at the end of the day.

Hopefully that was clear enough to follow.

#3  

Thanks. I didn't see such command formatting / parameters mentioned in the Script Command Manual. It made it also sound like the command was strictly for servo movements rather than the h bridge.

Frank

PRO
Synthiam
#4  

Thanks Rich! Great info:D

At the top menu of this website is a button labelled "Tutorials". Press that and there will be a tutorial section that introduces how ARC works and specifically, what a Movement Panel is. It is very recommended that you follow the tutorial process steps regarding movement panels will be clear:)

I know you'll be looking back at this question in a few days and say "ooooh, I get it now!"

:)

United Kingdom
#5  

You can also use the script console to carry out simple 1 line pieces of code such as the Forward(255,1000)

I didn't mention that you need to have the movement panel/hbridge set up in ARC first too.

Like DJ said, the tutorials help A LOT!.. So does just playing with the commands as I have found out tonight.