Would this shield work/

Would this shield work http://www.makershed...oductCode=MKAD7 with a Netduino Plus? I am building a simple elevator, and I have a very powerful Weedwacker motor to lift about 5-10 pounds about 30 feet into the air. Any other help would be very much appreciated, I have already built the assembly, I just need a power source and controller (Hopefully my Netduino) -Cwbh

CwbhX, Are there schematics available? Who makes it? Three things to find out: 1. Can it work with 3.3V? The answer is probably yes. 2. Which PWMs does it use? Netduino's 32-bit chip has 4 PWMs (while Arduino's 8-bit chip has 6 PWMs). The four center ones line up--but you'd need software PWM for the outside PWMs (or just don't use those two). 3. Are there ICs on there in addition to H-Bridges? If so, you might need to create drivers... Chris

I going to be honest here and say that I didn't understand a bit of what you said. What is PWMs, ICs, and H-Bridges? Sorry I am quite new to all of this.

I did find this website, it seems to have created a lot of projects seen on Make, and look reliable. How to

Thank you!

P.S. I know some C, but will buy a C# programming book ASAP.

Moderator edit: removed excess "http://" from link

I going to be honest here and say that I didn't understand a bit of what you said. What is PWMs, ICs, and H-Bridges? Sorry I am quite new to all of this.

I did find this website, it seems to have created a lot of projects seen on Make, and look reliable. How to

Thank you!

P.S. I know some C, but will buy a C# programming book ASAP.

Hi CwbhX,

That's fine--no worries. There are lots of people here who would love to help get you up to speed on how these things work.

Let's start here: please find out who the manufacturer of the product is. Is it the Adafruit Motor shield, or is it made by someone else? Once we know this, we can track down the schematics, talk about how to read them, figure out whether they use the PWM feature of the Netduino, etc.

As for PWM: PWM is pulse-width modulation. Have you seen electric signals on an oscilloscope before? In its simplest form, PWM creates "square waves". These square waves consist of a signal being on (high, 3.3V) for a certain amount of time and off (low, 0V) for a certain amount of time. The switch between the two is almost instant--so the signal "wave" has square corners. I'm sure we can find a photo if you'd like to know more.

Anyway, PWM has three nifty purposes (among a bunch of others):
1. LED insensity -- changing the DutyCycle of the PWM (0-100%) dims and brigtens LEDs accordingly. At 1%, the PWM would make sure that the signal is on 1% of the time (say on for 10 microseconds then off for 990 microseconds then back on, etc.)
2. Motor control -- this works the same way as LED intensity. By turning the signal on and off rapidly, we can control the motor speed. The more that the signal is on vs. off, the faster the motor turns.
3. Servo control -- in this mode, PWM creates a signal every ## microseconds (the period), as specified by the servo's specs. The length of that signal (the duration) tells the servo what degree to turn to.

Does that give you a good primer?

See you if you can track down the manufacturer and webpage for the product (where the schematics and details are listed) and go from there. If you're looking to pick up the Adafruit Motor Shield, we can just start there...

Fun projects ahead...

Chris

Okay, looking at this closer...

This appears to be the Adafruit motor shield. Okay, great. Here are the schematics.

The motor shields uses all six PWM lines of the Arduino's 8-bit AVR chip. The Netduino's 32-bit AVR chip only has 4 PWM, so two of the motor control headers (left or right side, depending on how you look at it) won't work today.

The one side of the motor control shield should work fine to drive stepper/DC motors. Additionally, the connection for 2 servos should work fine. You should be able to use an existing servo class from the forums (search in the project showcase).

There are some other motor shields--like the DFRobot shield--which may make it easier to use your motors/servos by exposing the 4 PWMs directly. [Does anyone else here have a recommendation on other motor shields?]

Chris

P.S. We're planning on adding "software PWM" in a future firmware update--which would let you use one or two additional motors on that shield. It's purely experimental at this point, but it should be doable--at least for motors and other simple activities.

Okay, Thank you very much Chris! This does help me a lot. I have seen oscilloscope before. I now believe I know exactly what a PWM is. I am wondering now if I could use it to control the motor. I believe so as it takes 12Volts and about 1-1.5 Amps... Does this sound right? I couldn't get any of my adapters to power it that are less than 1000mA. Is this the Motor Shield from DFRobot? http://www.dfrobot.c...1&product_id=66 I am most concerned about powering the motor. Thanks for all the information! -Cwbh

I think that you're looking for this one: http://www.dfrobot.c...9&product_id=59 You'll provide power directly to the shield for the motors--and then the Netduino will give the shield signals of "forward/reverse" via two of the digital pins and speed via two of the PWM pins. Chris

Thanks a lot Chris! I will Get my order in ASAP. I just got a C# book for beginners about 5-10 minutes ago.
Will it be more or less Plug n' Play?
I will probably post the project when I complete it

P.S. I plan on using C# with software, so I can understand it better and use it more for hardware (Netduino).

Cwbh

EDIT: It says it will take power directly from the Netduino, perhaps I should get one where I can attach mine own as well?

EDIT 2: I found this one http://www.dfrobot.c...9&product_id=69 It is two amps 7-12 volts and can use external power.

I Have the elevator working now, just with a switch and a battery. I also posted it in the project section with a video. I have updated the design a bit since the video though.

Well, the Motor Controller arrived yesterday, and to be honest I do not understand how I will program this. Right now simple is better.

Well, the Motor Controller arrived yesterday, and to be honest I do not understand how I will program this. Right now simple is better.

Did you get the DFRobot one? Are you planning on using motors (controlling speed) or servos (controlling position)?

Chris

Well, the Motor Controller arrived yesterday, and to be honest I do not understand how I will program this. Right now simple is better.

If I'm not to busy I can make a class for you. Don't count on it though, you should try to figure it out yourself first.

Which one did you get?

Oh, thanks guys. I am really busy this weekend. Chris, I bought the 2A controller from DFRobots and plan on powering simple motors(Speed), and OZ it would be great if you could make a class, though I really do need to learn for my Robotics team. All help would be very appreciated -Cwbh