Just wondering if anyone has any robotic curriculum? Are there any teachers or professors using these bots in the classroom?
Hi, I am planning to use Zumo in the classroom.
According to my projects, I’ll start with simpler robot kits the students can build themselves (a chassis, two wheels, casters, an arduino uno, a sensor card, a bunch of sensors to connect when needed, dc motors with their L298 driver, and little more), and then I’ll go with Zumos.
Nothing ready, yet. I’ll share my experience with you, if you’re interested.
At present, I have to decide which model to buy: 50:1, 75:1, or 100:1 gear ratio?
I understand that the three different assembly options give different speed/torque, Of course 50:1 is the fastest and 100:1 is the strongest, so to say. I need the robots for my lessons, so I don’t have precise needs, I don’t need extraordinary speed, thus I’d probably take 75:1 or 100:1.
By the way, any advice about it?
Some Internet site where the three options are reviewed?
How slow is the slowest one?
In this moment I am searching the forum to see if any discussion about the subject already exists.
I see you posted a similar question on another forum thread. I have posted a response there.
I am hijacking this thread rather than starting another one on a similar topic. If there is a better/ more recent one I should jump on, let me know.
I am teaching a robotics class next year and I am evaluating the Zumo for that class. The three projects that I am planning are line following, traversing a maze (using encoders), and Sumo competition. Is there any problems with using the encoders in the Zumo chassis? Is one encoder a better option for this than the other?
Also, the Zumo user’s guide does not include by-pass capacitors. Are they not necessary? If you suggest them, is 1nF the right value?
The Zumo shield for Arduino does not have a great way to add encoders that does not require modifying the chassis (and potentially damaging it). You might consider our Arduino compatible Zumo 32U4 robot which includes encoders.
You should not need any added capacitors for the motors on either Zumo model, and you should not add capacitance to the motors on the shield version since the motor drivers used on it are sensitive to added capacitance.
Thanks for your help with this. I have to look at the 32U4. Building the robot and making design decisions/tradeoffs is part of the learning objectives for the course so I want to have a platform that is somewhat customizable.
I use them when I teach my c / c++ class. FYI - they use jumpers to switch the sensors. They are located on the bottom / top line reader sensors. And yes, it does come of, it just slides into the mount. I also do some exercises where they navigate around items.
Thanks Jim. I’ll look into them.
Two follow-up questions on this topic. First, is it possible to change the sensitivity of the side sensors? I am working on solving a maze but the sensors dont reliable sense when there is a wall or an opening next to them. Second, with the preassembled 32U4, is it assumed that we unsolder the main board to solder in headers? Anything to be aware of when doing that?
Can you post a video showing the unreliable behavior? Also, what have you tried so far to get the Zumo 32U4 robot to follow your maze course?
No, you do not need to desolder anything on the main board to remove it from the chassis. You can separate the Zumo 32U4 main board from the chassis by doing the follow:
- Remove the batteries
- Remove the tracks
- Remove the front sensor array
- Unscrew the four screws
- Remove the blade
- Compress the spring on the battery contact soldered to the board until it will fit through the hole in the chassis
- Remove the board
Note that since the motors are soldered to the board, they will be removed as well. The only thing supporting them when they are removed from the chassis are the two jumper wires, so you should handle them carefully.
Our maze currently has 6 in wide lanes. We have the Zumo making it’s way down the lane correcting as it goes using the side sensors. The values we get are all 5’s and 6’s so the corrections come very close to the walls and we have to go slow but it works. When we get to an opening on one side however, the opening does not show up, the values either stay 5’s and 6’s or occasionally we get a 4 on the other side (and the Zumo veers into the wall). Have we missed some way to increase the sensitivity of the side sensors to give us more granularity for near objects? We have played around with the light intensity with no change.
Thanks for the instructions on adding headers.
Increasing the brightness of the IR emitters would increase the sensitivity of the sensors, although it sounds like you already have tried adjusting the brightness levels. What values did you set the brightness levels to and how did you determine that the values were successful and unsuccessful? I suggest further experimenting with the
Zumo32U4ProximitySensors::setBrightnessLevels function in the Zumo32U4ProximitySensors library so that you can find some level that can trigger the sensors to detect a wall on either side of the Zumo, but dim enough to not trigger the sensors when there is no wall.