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Data transmission from MSP430F2619 to PC

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Posted by janmay b c

on Feb 15 2012 09:20 AM

Expert1235 points

Hi,

I really hope that one day i will be helping others on this forum,

rather then screaming "help" all the time :-)


But for now here's my current problem:

Goal: To send ADC converion result to PC.

Background : Initially the idea was to use the FT2232D chip to send data to the PC,

but i  really am not able to make this scheme work.

Current status : with my project guide forcing me to use the

current board to send data to the PC,

i have been left with no other choice but to send data through serial port.

The "HELP" part :


1) How will i send the data to the PC (SPI or UART) and which pins do i need to bring out

( coz its better to know which pins will be required before i mutilate my PCB ) ??

2) I did some snooping around the internet  and found that a level shifter is required in-between the

MCU and PC, i wanted to know its part number?

If there are any other links/webpages/schematics that elucidate this scheme, please post them.

Buying another board is not an option now, as my guide wants results out of my current board.

If someone could help me out here i would be  very much grateful

best wishes

janmay

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Posted by Roberto Romano

on Apr 28 2012 14:39 PM

Suggested Answer

Mastermind6840 points

janmay b c

I found the MSP-TS430PZ100USB to be a good choice. But i find no USB transfer chips such as

the FT2232 or the TUSB3410 in the schematics of the target board.

Hi Janmay, I see you resumed an old thread, this solution can be appropriate if you wish to transfer data from pc to MSP at high speed directly from USB to ram. If you need exchange few data bytes and some commands through a (SLOW) serial connection the external USB chip is appropriate.

So a simple launchpad has serial capability on board and this is the lowest cost solution ever when testing, on production a ftdi or similar low cost device can fit in place of TUSB and MSP on launchpad. With a low cost chip you still can program (not debug) the MSP on board in BSD mode.

If you need faster data transfer at USB speed then the 5xx and 6xx series are more appropriate to, cost and complexity are more far from simple solution and some pc side driver has to be written (Nightmare prone and expensive in windows).

Other faster approach are to use LAN (unsopported by MSP series), LAN never require write a device driver or te new approaching wireless/BT interface spread over on cellphone and pad. see here for reference on wifi. and here for High speed BT

After that a note on how to select an MCU:

what you need to do with? This is the first missing question (can also be reserved and not disclosable).

Wich data rate do you need?

Is isolation necessary from PC and or ground?

Are battery operation a required feature?

How much computing power do you need?

--->>>Before to seek for a solution these point need to be in place otherwise the solution can be not so close to what is intended to realyze.

Regards

Roberto

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Posted by janmay b c

on Apr 29 2012 06:53 AM

Expert1235 points

Dear Sir,

Thanks for your quick reply.

Roberto Romano
what you need to do with?

Background: A friend of mine needs to sense the ADC channels repeatedly and send the data to PC (for which application, i do not know)

So, basically he needs a ready-made MCU mounted board with USB capability.

In short: He just wants to plug-in the target/evaluation board to the PC via a USB cable, and transfer data.

So, he asked me whether there was any board available from TI hosting the MSP430 MCU, capable of doing
the above mentioned function. Since, i struggled with a separate chips(FT and MSP) i too am interested to know whether

such a board is available or not.

Roberto Romano
Wich data rate do you need?

Sir, i did not understand this question. are you talking about MB/s or baudrate??

Roberto Romano
Is isolation necessary from PC and or ground?

This question too i don't understand. Sir, How is it possible to isolate PC?? (Please forgive my ignorance)

Roberto Romano
Are battery operation a required feature?

Sir, This too i don't understand, are you referring to the MSP being operated by a 3 V battery??

Roberto Romano
How much computing power do you need?

Till now my friend told me that he wants to send ADC sampled data to PC, that's it !!

Roberto Romano
Before to seek for a solution

Thanks a lot for the evaluation board links sir, i just want to be extra careful in suggesting the

right board to my friend, so that he does not lose money and his time unnecessarily because

of my mistake of ordering a wrong board .

best wishes

janmay

Posted by Roberto Romano

on Apr 29 2012 08:34 AM

Mastermind6840 points

Hi Janmay,

janmay b c

Background: A friend of mine needs to sense the ADC channels repeatedly and send the data to PC (for which application, i do not know)

So, basically he needs a ready-made MCU mounted board with USB capability.

You have no idea of what it think to do, if slow data read is enough again speed of serial emulated communication in order of few 10K bit rate can work. If faster sustained data reading are necessary at full ADC speed then just the native USB can sustain at full 12 or 480Mbps, so this point must be clarified to select a launchpad or an USB part.

On the other side one of wifi or BT part are more simple to use, you don't need drivers for USB and data can be simply streamed thru interface to PC and cellphone and tablet too.

janmay b c

Thanks a lot for the evaluation board links sir, i just want to be extra careful in suggesting the

right board to my friend, so that he does not lose money and his time unnecessarily because

of my mistake of ordering a wrong board .

In front of preceding part this is not your failure but simply the missing information, overkill it suggesting 5-6xx USB full speed part. The trouble start on winzozz side and cannot be so simple to solve.

janmay b c

Roberto Romano
Wich data rate do you need?

Sir, i did not understand this question. are you talking about MB/s or baudrate??

Bitrate is same of baudrate on unmodulated baseband communication so on serial line common speed are in the range of 110K to 960kbps max, on USB side the speed is 12Mbps for USB1 or USB2 low speed to 480Mbps USB2 full speed.

janmay b c

Roberto Romano
Is isolation necessary from PC and or ground?

This question too i don't understand. Sir, How is it possible to isolate PC?? (Please forgive my ignorance)

TO avoid introduce common mode or ground loop noise often is required to have pc ground separated from external device. To accomplish this a galvanic isolation can be added on communication side (standard for firewire and lan) or a air gap separated communication in place so WIFI and BT are not only galvanic but physically separated too. Using one of these two technology also permit to transport data to other device than pc.

So before to say I think this board can fit your need ask your friend to answer all the question.

Regards

Roberto

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Posted by Jens-Michael Gross

on Apr 30 2012 11:20 AM

Guru140650 points

janmay b c
In short: He just wants to plug-in the target/evaluation board to the PC via a USB cable, and transfer data.
So, he asked me whether there was any board available from TI hosting the MSP430 MCU, capable of doing
the above mentioned function.

Why not using the LaunchPad?
Take a look at this nice project. It uses a standard LaunchPad to show an analog input signal on an MSP pin as a realtiem scope signal on the PC.

_____________________________________
Before posting bug reports or ask for help, do at least quick scan over this article. It applies to any kind of problem reporting. On any forum. And/or look here.
If you cannot discuss your problem in the public, feel free to start a private conversation: click on my name and then 'start conversation'. But please do so only if you really cannot do it in a public thread, as I usually read all threads. And I prefer to answer where others can profit from it (or contribute to it) too.

Posted by janmay b c

on Apr 30 2012 11:23 AM

Expert1235 points

Dear Sir,

Thanks for your detailed reply and very much sorry for my late reply !!

The Intended applications:

1) To sense voltages from 3 voltage sensors repeatedly and sending the data to PC

2) A PC oscilloscope - where any wave form sensed on the ADC channels is seen on the PC, via a GUI.

For the time being the focus is one 1).

Now, it is definitely not possible for us students to write drivers on the PC side. So for these applications, if possible

please suggest an appropriate evaluation board/target board, wherein data from the MSP430 can be viewed on PuTTy.

Thanks a lot for your invaluable inputs sir. My friend and also i will be extremely grateful to you if you could suggest an suitable ready-made MSP430 board from TI. Thanks.

best wishes

janmay

Posted by janmay b c

on Apr 30 2012 11:33 AM

Expert1235 points

Dear Sir,

Jens-Michael Gross
Take a look at this nice project

Thanks a lot for the link sir. Launch pad is fine sir. But in my college they want to buy a MSP eval/target board, which will be used for future projects as well.

So, we are avoiding LP for the time being, as it has some limitations.

best wishes

janmay

Posted by TonyKao

on Apr 30 2012 13:52 PM

Suggested Answer

Expert1435 points

janmay b c
Now, it is definitely not possible for us students to write drivers on the PC side. So for these applications, if possible

Whew. That's strange - I did something like that at school. So students should be able too, it isn't soo hard.

For an oscilloscope the question is how much bandwidth shall be achived? How precise? Just as a showcase project or for real work?

There are a bounch of development boards for MSPs with onboard USB, for example this one.

--
Regards,
Jan

Oxfam Trailwalker 2012 - Runner

Found any horribly english mistakes? - Drop me a note as private conversation via my profile if you like ;-)

Posted by janmay b c

on May 01 2012 08:50 AM

Expert1235 points

Hi Tony,

Thanks for your reply.

TonyKao
It seems to me though if you're developing a straight-up MCU-to-PC application

Yes, that's the main idea. Finally, i have decided to order the MSP430F5438 Exp Board , as it is currently available with my local, element14, distributor and because it looks apt for future projects as well. Thanks for your input.

best wishes

janmay

Posted by janmay b c

on May 01 2012 09:01 AM

Expert1235 points

Hi Jan,

Thanks for your quick reply. And thanks for replying to all my queries, i greatly appreciate it.

Jan
So students should be able too, it isn't soo hard.

I have not tried it, nor did i face a situation wherein i had to write it on my own. Please, if possible, do post any links/sites which help beginners to write drivers on the PC side.

Jan
For an oscilloscope the question is how much bandwidth shall be achived?

About 5 kHz.

Jan
How precise?

Err... I really do not know what precision for scope means, do you mean how much noise being eliminated?? or reconstruction accuracy of the wave at the PC side??

Jan
Just as a showcase project or for real work?

Grades are involved :-), so, real work.

Jan
bounch of development boards for MSPs with onboard USB

Yes, currently ordered the MSP430F5438 Exp board.

best wishes

janmay

Posted by Jens-Michael Gross

on May 02 2012 09:58 AM

Guru140650 points

janmay b c
Thanks a lot for the link sir. Launch pad is fine sir. But in my college they want to buy a MSP eval/target board

Well, the PC side of the project won't care who's on the other side of the seriel data link.
It just connectes to a (selectable) COM port with a (selectable) baudrate. And sends dommands and receives values. So you can as well connect a 5438 eval board or an MSP with internal USB, as long as it has a virtual COM port driver on the PC side.

Of course, the MSP part of the software needs to be adjusted to the actually used MSP (including a different ADC, if necessary)

P.s.: I ported the PC side of this project to VisualC++, the original project was C#.