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Question about Serial Port on Panda II and suitability of FEZ Ultimate kit for hobby project


#1

Hello,
I hope I have the correct forum. I was considering buying the FEZ Ultimate Kit which has a Panda II and a Fez Touch for a hobby project I want to pursue.
I have an MSP430 based data acquisition board that can communicate over serial port. I would like to get that serial port signal on a .NET micro framework board and display the results on a screen. I was thinking that perhaps the FEZ Panda II and FEZ touch would do the trick but can’t be sure. I’m not really a hardware guy, so I need a little help. The specs for the FEZ Panda II mention serial but I sure don’t see a serial port on it. I was hoping I could just run a serial (RS232) cable between the MSP430 board and the micro framework board. Would the FEZ Panda II do this or is it some other type of serial connection?

I’m not sure if the FEZ touch does everything I need. I need to display voltage versus time on the screen, but only about 300 data points. I also need to show the current voltage and a few other statistics. Nice to have would be some icons such as up/down arrows, warnings, etc. I’ve already done all this as a WPF app running on a PC that talks to my MSP430 board via serial. Hence the interest in .NET micro framework. The docs for the FEZ Touch have a warning about not displaying jpg or gif so perhaps I can’t display icons? Can someone expand on the FEZ Touch limitations?

If the equipment I have picked is not appropriate, perhaps you could point me to a better alternative. And perhaps there is a board that has the GUI already on it? One option I was looking at is the MicroLCD from sytechdesigns
http://www.sytechdesigns.com/MicroLCD.htm

Perhaps you could briefly say what the pros/cons of the FEZ system are?
Thank you very much for your time,
Dave


#2

Have you seen this video? http://code.tinyclr.com/project/328/fez-touch-ui-controls/


#3

To connect a Panda II to an RS-232 device you need a RS-232 shield. I have used one and they work great.

GHI has them on sale now!

http://www.ghielectronics.com/catalog/product/182


#4

Mike,

Thanks for the quick reply.
The specs say that the RS232 Shield is for the Domino. Will it also work on the Panda II? And will I still be able to hook up to the FEZ Touch or do they both plug into the same spot?

Thanks,
Dave


#5

Dave -

The RS232 shield is Arduino pinout compatible, which means it will work on the Domino, Panda, and Panda II. The FEZ Touch is specifically designed to be compatible with the Panda II, and no, they don’t use the same pins. The question would be do the shield and touch PCBs overlap in such close proximity. They might. There is a ribbon cable extender for the Touch that takes care of that (possible) problem.

I have the necessary parts to test the possible overlap issue, and will post a picture later this evening (EST). Remind me if you don’t see it by 10pm or so.


#6

Hi Dave11,
Yes panda ii support rs232 shield. but you don’t need it. if you have fez touch to you should have to use com1 on panda ii (digital 0 and 1 for rx-tx and 5/3v3 volt with gnd). i have rs232 shield, but i have never used. what ever you need is on panda ii.
Judasis


#7

@ Judasis - to the contrary, the RS232 shield contains a level shifter that handles the voltage conversion between RS232 (3-15V) and the Panda’s serial ports (3.3V, 5V tolerant). If Dave’s device puts out >5V, bad things may happen, the least of which is bogus data. The shield handles this conversion bidirectionally. If Dave’s MSP430 board outputs <5V via RS232, he may not need the shield.

Take a look at the RS232 Standard Details section, http://en.wikipedia.org/wiki/RS-232


#8

Hi ramsomhall,
"If Dave’s device puts out >5V, bad things may happen, the least of which is bogus data."
you are right. thanks for info…
Judasis


#9

I think what you mean is “level shifter”, not “shift register”.


#10

Good catch… fixed.


#11

dont forget that the RS232 also might send the ATT signal that pin 7 and 4 (one of those) on 9pin connector have, I’m not a pro at the serial RS232.

Does the application require time sensitive response and data?
Is there going to be alot of data that might over flow the Panda2?
Is C# a language you are familiar with?

please feel free to respond, and add more if you can;
the guys here at the forums know a think or two about these devices. :slight_smile:
maybe someone might suggest a FEZ Rhino can be a better alternative, if the applicantion needs the extra performance.


#12

Thank you for the response Alex (Console.WriteLine(Alex), you bring up some good points I should have asked about.

Here is the situation…
I have an MSP430 board (the receiver) that receives information every 30 seconds from a Transmitter via Radio. Every 30 seconds the two boards have a brief conversation and based on data from the Transmitter, the receiver ask for more or less information. The messages back and forth are about 20 bytes long and typically* there are less than 10 each way.

I have multiple objectives.

  1. First and foremost is to display the data. In spite of all the bytes I mentioned the actual info to display is rather modest. Normally it might be just a temperature value as a function of time. Occasionally there will be status bits that Id want to show (perhaps just text in red). So, just a graph with < 300 data points and some statuses. Frankly the most important thing would just be a simple textbox with Temperature = xxx.

  2. I am considering changing the role of the MSP430 board (receiver) to just be simply a relayer of information. If I did this, the .net microframework board would need to do some simple processing based on the messages from the transmitter. Things like, ah the temperature is X, also ask transmitter for humidity. If I went this route, the answer to your first question would be, yes, the application requires time sensitive response and data because the transmitter will turn off it doesnt hear from someone within ½ second.

#2 is actually my preference as I have already developed a WPF desktop solution along these lines. Its slightly different; it gets the raw data from USB stick with a radio. The WPF app dutifully processes data and displays it, and sends out requests for more data via the USB stick.

If youre thinking at this point, why on earth is there this middle layer of the MSP430 for the receiver, youre way ahead of me. Eventually it might be possible to ditch it, but for now I have a MSP430 gray box that can either just passively send messages to the microframework board and receive and pass messages along to the transmitter, or it can do the hard work and have microframework board be just for display. If Im planning on dumping the MSP430 board (my preference), it would be nice to have it do as little as possible.

A few other points…

  1. The MSP430 board has a serial (RS232) port and can transmit at 115200 or lower. What should I be using for the microframework side?

  2. I put a ‘* up above when I talked about amount of data coming over. Occassionally, the receiver (whether the logic is in MSP430 or microframework to be determined) will decide that it is missing data and ask for a potentially large amount of data. On the order of 2000 bytes. So the answer to your second question is that normally, there will be a conversation of a few lines of 20 bytes each, but occasionally there is the need to receive 2000 bytes.

I am quite fluent in C#.
Re: Rhino, see my other posting!

Thanks to all the posters. I really appreciate it!
Dave