View Full Version : Sending the sensor data from a car to my PC , But : !! wireless !!! ( When t

05-31-2005, 10:06 PM

I am using a basic stamp to collect data from temperature sensors and basic stamps are very good
for this job.

But I don't know how can I send the data from the car to my PC

I will install some sensors like temperature for monitoring the car
but the problem is that must be wireles because the truck will
be in an other city.

Some help please, thanks: Joe


05-31-2005, 10:13 PM
At a previous employer, we used·a system as you describe to monitor a fleet of prototype vehicles· used for 100k durability testing.

I cannot remember the name of the company at this time.....try google.

Paul Baker
05-31-2005, 10:19 PM
Ok you need much more than just a wireless connection, standard wireless is only going to get you a few miles range at most. If you need to remotely monitor something further than that distance your best bet will be using a cellular module. www.sparkfun.com sells the GM862 for $120, in addition you will need to get a cellular account with AT&T, T-Mobile or Cingular and a phone with a SIM card, you then plug the SIM card into the cellular module to activate it's use.

You may be able to piggyback onto existing fleet monitoring systems, but of course there will be significant costs invovled in that route as well.

05-31-2005, 10:30 PM
Is this for a commercial application of private.

What kind of distances are involved.


05-31-2005, 10:31 PM

"or" private


05-31-2005, 10:36 PM

If you are not aware, you can edit your own posts....click on the pencil Icon in the upper right corner.

SPENCE said...



06-01-2005, 12:36 AM
Hi again:

Distance could be 200 miles.
This is private project but I think that could be a good idea
to monitoring some cars.

But first of all I need to know if it is possible.

Do you know something about collecting data from
a Basic Stamp?

Thanks: Joe http://forums.parallax.com/images/smilies/confused.gif

06-01-2005, 01:00 AM

don't know where you are so this applies to the usa only. I may be possible in other areas..

1. Get your ham ticket.

2. Get two 2 meter 50 watt base/mobile sets. Get 2 tnc's which are radio modems. They convert rs-232 to audio 1200 baud on vhf/uhf or 300 baud on hf. And on the other end convert the audio back to rs-232.

You can do this direct at small distances. 25/100 mile or thru relays for further distance. Once set up the cost per month is $000.00...... If you use hf radio it would cost more but
might work using beaconing on aprs system like the hams do for weather information. Many of these stations are remote and unattended.

If you use cell or sat telephone the cost will be much higher in the long run. Ie a 2 meter rxtx is about $165 or less for icom ic-2100. Works on 12vdc fixed and mobile. You can also send gps locator thru the same link. There have been several articles in n&v on gps using the stamp.

There may be a packet radio network already operating in your area. Find a active ham familiar with packet and aprs....
Then ask many many questions.


Paul Baker
06-01-2005, 01:00 AM
Like I said before your required range is way beyond what is possible through ordinary wireless communications, you will need to piggyback on an existing communication infrastructure, whether its cellphone or sattelite/cell based fleet monitoring system. Since this is a private venture, the fleet monitoring system will not be worth the expense, so cell is your best bet.

Or you can go SPENCE's method of amateur liscence technology, but there are very specific rules guiding transmission of data across those airwaves to where they need to be short and infrequent. In addition you'll have to either do bidirectional communication to support handshaking and collision detection or send packets filled with enough redundant information for the receiver to reconstruct the correct message (since you cannot assume the packet will be transmitted error-free).

Post Edited (Paul Baker) : 5/31/2005 6:04:32 PM GMT

06-01-2005, 04:49 AM
If you go the HAM way....
you will have a callsign with your license. So you have to transmit your callsign along with you rmessage etc...
You can not transmit continuously...there's no specific amount of time....but it's an etiquette thing really.
Just know that you are not allowed to transmit encrytped data.....so when using Ham setups, anyone will be able to see your data. So if you start transmitting location data (GPS lat/long), anyone will know that's on the same system!

Just a heads up!


"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."

Chris Savage
06-01-2005, 05:26 AM

·· I am beginning to think a Cellular Phone system or GSM (?) Modem...

Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

Mike Cook
06-01-2005, 10:29 AM
Sounds like a great application for SMS using GSM/GPRS, if the messages are under 160 bytes.

Depending on the number of vehicles in your application, there are service providers such as www.korewireless.com that re-sell air time. Using a service such as this, allows you to use whatever carrier that's in your area (AT&T, Cingular, T-Mobile, and a bunch of smaller regional carriers). This greatly increases your "in-network" coverage area.

If your just experimenting you can pick up a prepaid SIM and start using it with out a contract. Of course you'll need a modem or GSM cell phone with a serial interface. I would suggest using a GSM modem because they can be programmed to remember most of the settings required for accessing the GSM/GPRS network and you can transit a message as simple as:


if your sending to another GSM device or if the SIM is provisioned to send to an email address, (T-Mobile example):


The second example will send a SMS message to an email address, you could then write a program to retrieve the email and process the data.

Most GSM/GPRS modems can also send data via IP using either UDP or TCP packets, some even have their own TCP stack built in so all you have to do is send a command to the modem to go into data mode, and start sending ASCII or binary data to a server that is waiting to catch the data.

For more information on GSM/GPRS modems do a google search or go to www.enfora.com Enfora has quite allot of information, on their modems, that is available for download.


"OEM NMEA GPS Module" Now available on ebay for only $19.99

Product web site: http://www.allsurplus.net/Axiom/

06-03-2005, 08:58 AM
Many thanks to all the people that answer :

Mike Cook, Chris Savage, steve_b, Paul Baker,

Thanks: Joe http://forums.parallax.com/images/smilies/smile.gif