Hi Chuck,

N+ Tech Specs:
Digital pins 11-13: SPI MOSI, MISO, SPCK

Thanks for anwering, I did follow the tutorial referenced to me here in one of the links but maybe it is for an old Netduino and not for the Netduino Plus as they are using D10 as you pointed out, so I am going to try with D11 instead of D10 as suggested.

So, Stefan's NETMF Toolbox works with the LCD itself, right, not with the backpack?

I'll put the code in dropbox or skydrive and send you the link to it.

Thanks

It works with the LCD shield. But I think that if you get the SPI correct that it may work, or at least help get you started.

Chuck

Thanks for the info, I am ordering the 498. Yes, the class would be helpful, I apreciate that.

Giuliano,

You adding a display to the sprinkler system?

I have the 498 and it works very well with Stefan's NetMF Toolbox, it took about 30 minutes to solder all of the pins and headers but you should not have any problems (.1" between connections). Plus you only use a few IOs.

Chuck

I've followed the instructions of the blog provided but cannot get the LCD to work, all I get is a Red LCD as soon as I plug it in to the power.

My wiring is as follows:

CLK going to D13, DAT going to D12, LAT going to D10, 5V to 5V on the Netduino and GND to GND on the Netduino.

Mike,

I have a backpack and LCD coming, may take a few days to get here. I currently have only the Adafruit RGB Negative LCD Shield and it seems to work correctly using Stefan's NETMF Toolbox sample program.

But from looking at the wiring and the pinout card for the Netduino, you are not connected properly for SPI. The SPI pins are D11, D12 & D13 not D10, D12 & D13. Netduino Plus Pinouts

I assume that you have worked through the Adafruit tutorial? LCD Backpack Tutorial

Also to work through the code I will likely need to know what you are importing / references. If you have Dropbox or simular it may be easier to post the code there or email it to me.

I will at it some more after supper, but need the backpack first.

Chuck

Mike,

I think I told you wrong, and I think your connections are right.

On the Arduino and Netduino:

• D10 is the chip select and must be low to write to the LCD backpack(not shown on Pinout but any DIO set to false should work. Connect to Lat(Latch) on LCD backpack
• D11 is MOSI Master Output Slave Input (from Arduino or Netduino to LCD) connect to DAT (Data In)
• D12 is Master Input Slave Output (not used on LCD backpack).
• D13 is Clock tells slave to recieve data. Connect to CLK (Clock) on LCD

Try setting D10 to false.

Chuck

Has anyone experienced, that their analog readings are wrong?

Measured directly on the sensor, i get a value of 0.47v but Shieldbase reads 0.14v... it seems to be dividing the actual value with the voltage...

Nicky which method are you using .Read or .ReadRaw? The .Read gives you a float value 0 to 1.0 the .ReadRaw gives you an integer that reads 0 to 4095.

Chuck

While I don't pretend to know the cause of the delay or lack of communication I have to give Chris the benifit of doubt. Sometime people tend to have a short memory. If you look back through the posts on this forum and look at the timestamp on the post that Chris has made you will find that they are posted at all times of the day. He has spent considerable time helping some of us. What ever the reason for the delay it has not been that long. The firmware made it out with some features not working. They may have been able to get some of the problems fixed and release the update last weekend only to discover new problems. I have to think that the extra time will pay off in the long run with a better product. No matter the cause of the delay (personal, illness or just trying to get the fixes done) I think most of us should be able to find a little patience and wait a little longer. Chuck

Hello guys,

I plug a 9V power to the netduino this time and try to run the program again, it didn't work yet.

I noticed there're 4 LEDS near the Motor pin.

when I set MotorDriver.SetState(HBridge.Motors.Motor2, 50); it always red light on, if I gave MotorDriver.SetState(HBridge.Motors.Motor2, -50); the green light on.


However, when I mount the Motor on the pin, there's no more green light, the RED light always ON with some sound and I feel hot from L298P chip. I'm afraid if the chip will explode


Any guys have idea how will it comes? Please HELP!

Kaiser,

Without a picture of what you have wired up it is hard to be sure what you actually have.

But in general if a chip is hot you are drawing excessive current or the chip is not heat sinked properly.

The best i could tell you are pulling power from the 5vdc regulator on the Netduino, that regulator has a maximum output of 800 milli amps. That is sufficent for a small 5 volt servo. Anything more should have its own power, normally more than 5 volts depending on the motor. The 2 amp DFRobot shield can handle 5 to 35 vdc on the screw terminals, 6.5 to 12 vdc on the vin connection i.e. barrel connector of the Netduino and uses 5 vdc for logic power from the 5 vdc regulator.

Please take a look at Stefans Wiki page for this DFRobot Motor Shield and the DFRobot Wiki link that is on that page. It explains the difference between PwrIn and Vin and shows how to set the jumpers.

As far as the LEDs by looking at the schematic 2 LEDs are used for each motor, one for forward the other for reverse. If the LED goes out with the motor connected it is likely due to the load dropping the voltage that is needed to lite the LED i.e. you have overloaded the power supply (bad thing ).

Good luck,
Chuck

Finally, I made it. It turns out that nothing wrong with the wiring and programming. The root cause is my track were too tight and motor cannot be drive properly... I used the twin gearbox and chassis made by Tamiya. When I took off the track, it runs OK!

Next step, I'd like to consider if I need switch to external power maybe give two 9V battery connected in parallel way.

Thank you guys, you do give me a lot of help!

I wouldn't say nothing was wrong and I am not trying to be an A##hole. The condition that you had is called a locked rotor. The current can be over 10 times normal maximum current for the motor, which in turn can burn up a motors windings, commutator, controller or rectifiers of the power supply.

The thing is it sounds like no damage occurred, and we all can learn something out of the trials.

You did a no load test without the motor, a no load test with motor connected but not connected to the tracks would of saved you some time and frustration. I'll need to remember to do that when I start building a robot.

Glad you got it working.
Chuck

Hi, I just ported over some code for a CO2 Sensor found here and haven't been able to test it yet, but wanted to show everyone on here and see if anyone sees any problems with it. I'm not sure how this will work as it looks like the analog output voltage is 0-5.. If anyone has any suggestions, please let me know.

Joshua,

I haven't looked to much at the code, but it is good to see someone porting the Arduino Code over to C# and sharing it.

As for the 5vdc output that is too high for the Netduino ADC (max. 3.3vdc), but there are a couple of options.

• Seeing the module output is coming from an Op Amp you can setup a simple voltage divider (1.6kOhm & 3.3kOhm in series)
• It look like the Op Amp resistor R4 (7.5kOhm) is a surface mount device, you may be able to remove and replace with a 4.5kOhm resistor so that you get 3.3vdc at 10000 ppm CO2.

Chuck

ok. I have one of those smd resistor kits This one to be exact. .. It just doesn't have 4.5k in it. What formula do i use for those resistors?

Vout = Vin x (1+R4/R1)

R4 = ((3.3/0.6)-1)x R1

Or like above you can take a 5kohm multi turn pot (the ones that I use are made to go in a printed circuit board and have a multi turn screw to adjust) and set the wiper to 3.3 kohm an the value should stay where you put it and use can adjust the output if needed.

I've actually done this before.. it wasn't too bad. Would I be able to use a slightly smaller or larger value resister there.. I just looked at the price of those and id have to buy 100 of them at 3 something each just to get 1. I have This booklet of smds on hand and it has a 4.3kOhm and a 4.7kOhm in it. Would one of those work?

Joshua,

Where are you located (country), You should be able to find someone to to sell you a couple of them.

Also check Amazon Resistor Kit or Ebay Resistor Kit.

As to the value I use the formula in the data sheet, You can change the value but may need to change R1 & R4 the value I gave you was keeping R1 the same. Just play with the values using the formula to find a pair that works for you.

You could use a Potentiometer and put 5 vdc on it and adjust the wiper to 3.3 vdc. I have done that with 10 turn pots before.

Chuck

oh, ok. I see.. so the .6 is the max output of the sensor which is the input to the amp circuit and the 3.3 is what you want the Vout max to be. Is there anywhere you would recomend where I can purchase one or two of those 5kOhm pots at a decent price? I'm in the US btw.

Thank You
Joshua

Depends on how fast you need them,

Digikey care them search for trim pot or trimmer. Minimum Quanity is only 1. Digikey trimpots

Radio Shack may have them or one that will work in a local store they show them online. 10K 15 turn trimmer

Ebay has them in the US 5K Trimpot or from Thialand (7 to 14 days) 25 turn 5K Trimpot

It does not have to be 5k, about anything from 1k to 10k should be good I think the impediance of the analog channel on the Netduino is fairly high (current draw suddent effect the voltage drop of the resistor / pot.

Hope this helps, If you have additional questions I will be gone out of country for the next 3 days, but someone should able to help. Have a Merry Christmas.
Chuck

Thanks Chuck. could I replace it with one of these?

I'm a developer, not an electrical engineer, so I'm new to this.. however i do have a reqork station at my dispose. Is the smd above the correct package size?

I am not sure I would need to see one of the boards to tell, the removal of the old resistor could be a little tricky. Someone like Arron (often in Chat room) may be able to provide some suggestions. The 805 resistor size is 2.0 mm × 1.25 mm

Ulrik,

I think the new Netduino Plus 2, will give you more freedom, and if your goal is to learn more about basic digital electronics, this is IMHO the one to get. You don't really have to use a soldering iron if you can make things on a breadboard.

I agree that the N+2 would be a good starting point, it has the essentials on the board. And the price is right.

I have a Netduino Go Starter Kit, and i find it quite limiting, as the shieldbase has been in Beta for quite some time, and there has been a lot of small things that is not working.

As to the Go, Yes and No, it depends on the applications that you have in mind. If you are prototyping a project or need to build a module to do exactly what you want the Go is a great platform.

As for the time in Beta for the shieldbase, there are a lot of things that influence that, change in parts, availability of parts, change in visual studios, changes in NETMF, hurricanes and upgrades to existing products (N+2). Also if I remember correctly the release date of the Go was 4/8/12. It has come a long way. The number of existing module and the pending addition of GHI modules amazes me. I have tryed to buy all of the product line and I think that I have all of the available modules and consider them all a good investment.

Chuck

I'm sorry to keep posting questions, but creating a new topic would be wrong I guess.

Which jumping wires should I take to connect the netduino with breadbord ?? This might not be Netduindo related...

M/M, F/M or F/F?

Frederick,

Male / Male.

As to the second question, the kit seems to have most of the parts, I did not see a power supply, the USB will provde 5vdc to the Netduino. If you want to use more power than the USB can provide then a 9vdc power supply (wall wart) can be added. Just make sure that the center of the barrel connector is positive.

Chuck

Thanks Carb,

What I am also wondering... (sorry to keep asking questions in here, but I doubt creating a new topic would be better)

When applying shields, you lose some I/O pins...

- Can you still use a breadboard to prototype some things using the pins not used by the shield?
- Can we combine shields? I guess this is hard to do, since it might be possible that both shields will use the same I/O ports... Thats not working then right ?
- Are there any good lcd displays to prototype on a breadboard ? Since if I attach a wifi shield, I can not attach a LCD shield, or am I wrong here?

Thanks

Frederik,

You will lose some of the IOs depending on the shields being used. Outputs can be shared if they are needed by more than one shield for the same purpose i.e. an on/off signal. Inputs normally are not shared because each shield would provide signals back to the Netduino. Power and grounds can be shared assuming you don't overload the power supply. Pins used for communications can sometimes be shared i.e. I2C uses an Id code for each item that is on the channel.

IOs that are not being used can be used by a bread board.

Some shield can be stacked as long as the IOs and shield functions are compatable which each other.

Depending on the shields being used many allow configuration of the IOs to avoid conlict with the other shields that are being used. For example you may be able to select Com1 or Com2 for serial communications, this is often done with jumpers on the shield.

There are good LCD that can be breadboarded, But I would consider using an LCD shield with I2C or SPI control (uses fewer pins) or a LCD with SPI backpack. This macks the connections easier and there is code that will minimize your work. Check Adafruit.com for some ideas of what is available LCD shield or Serial LCD display

Adafruit has a lot of options and ideas, unfortunately most of the code is for Arduinos but that can be coded for C# or visual basic and has often already been done by others. They normally have good tutorials on how to use the products.

Also take a look at Stefan's Netmf Toolbox, he provides code in C# and Visual Basic, gives you sample codes, components needed and normally a circuit diagram on how to connect the items. Like this one Motor Control

I think I got most of the questions,
Chuck

Current draw for just the boards with power led on (barrel jack 7.5 vdc applied):

• Netduino = 32 mamp
• Netduino + = 41 mamp
• Netduino 2 = 22 mamp
• Netduino +2 = 122 mamp

I plugged each board into a precision power supply that displays applied voltage and the current that is being used.

 

Barrel connector input with the power supply programed at 7.5 vdc. No IOs other anything else connected. Some may have programs running, I did not erase boards, All have current firmware loaded. https://www.dropbox....nm/IMGP0265.JPG

Looks good Steve, I was thinking it would be nice to come up with a quick reference guide with code snippets for using Inputs, Outputs, Interrupts, Debug Statements, Buffers, Threading, Try / Catch, Arrays, Serial Ports, PWM, SPI, I2C and a few others. It might help some that are just starting with Net Micro Framework. But no SUX sockets. Chuck

I think this is a fantastic idea Chuck, and one I've been aiming at doing for quite some time now. I think I just need to get off my butt and start writing some. I've actually been developing a framework for a tutorial website, but have had so many projects on the go I keep getting distracted.

Steve

Lets see what the others think. May be in Wiki we can add something in both C# and Visual Basic. Stefan's toolbox has helped me a lot for examples on how to do things.

Chuck

Steve,

 

I didn't think Canadians were allowed to play with things that went boom! Or high voltage.

Hi Coyttl,

Thanks for replying.

I was hoping you could show me the syntax for how you open a com port and write to the lcd... is it kind of like doing a debug.print?

Also where do i connect the RX from the lcd onto the plus 2?

Thanks,
Donovan

Donovan,

Welcome to the Netduino Forum.

For connections on the Netduino Plus 2 see the Steve's Pinout Drawing. Netduino Plus 2 Pinout

As far as setting up serial communications, there are several examples here on the forum, some better than others depending on the task. Just use the search feature in the upper right corner.

Also checkout Stefan's NETMF Toolbox on codeplex. NET Micro Framework Toolbox It has samples and code in C# and Visual Basic plus circuit drawings. Even if you don't find exactly what your looking for you can normally find ideas that will put you on the right track.

Transmitting on serial is fairly easy, receiving is a little harder to get the buffer setup right so as not to lose bytes.

Chuck

Denisetoo,

 

You can display the Output window from the View, Windows Other pulldown or by pressing Ctrl-Alt-O.

Bendage, Very Nice Job, both your project and Mario's should be a great help for those of us with a programming handicap. I was going to look behind the console, but was afraid that the Phillip Head screwdriver might damage my touch screen. Thanks again, Chuck

Donovan,

Have you looked at Arron's Power Management Class. Power Management

It allows you to cycle the 3.3 & 5.0vdc headers (and other things). This would allow you to remove power temporarily from the shield to reset it, as needed.

Chuck