I was thinking about this. Since SPOT has two buttons (HELP and OK) that let you send a predefined message, in theory it should be possible to use it as a morse code transmitter. For example you could define HELP button as dot and OK button as dash (after all the HELP button on the SPOT looks like dot and OK button is longer in shape).

A person that would receive these messages could decrypt the transmition manually or I belive it would be possible to write some simple program that would take care of everything. The program would process the e-mails/messages, identified HELP messages as dots, OK messages as dashs and then it would translate the morse code.

For this to work effectively the SPOT would have to allow you to send messages in sequence, one shortly after the other. I don´t have SPOT so I don´t know how quick it is as far as sending e-mails/messages. Maybe someone here who has one could test it.

Some common words could be transmitted as aliases (shortcuts) like some people like to do when they write SMS. So it could save some time and effort.

It´s just an idea. I don´t know how well it would work and whether it would be applicable or even useful at all but if you needed urgently transmit a special message via SPOT or just for fun it might be the way.

Won't work

Or you could just walk out your message using the tracking function then when they look at google maps on the computer screen.... or even send a pictogram like Cerne Abbas Giant.

Why wouldn´t it work? (I am not saying you are wrong, I am just curious). Is it just impractical (because of long delay between messages or other issues) or it wouldn´t work at all?

I would imagine something like that could work, if you had someone listening to the messages in that kind of format. But in this case, your receiver is in a satelite, seeking messages in one of two given formats. Making modifiocations as you discussed would be changing the format into something the receiver, both man and machine, was not looking for.

It seems to me as if you would be sending out FM radio waves to be received by an AM receiver. If you could get the signal right so it was received, it's probably only going to sound like static.

The buttons probably send "do it now" type signals to code burned into the chips- they aren't on/off, they are the knocking over the first domino. Never mind that without the proper version of "hi, my name is" at the front of the message, the satelllite will think it is just noise- a packet with the wrong structure isn't a packet, computers are stupid. Too stupid to be fooled by something like this.

And more importantly, why would you want to do this?

The buttons probably send "do it now" type signals to code burned into the chips- they aren't on/off, they are the knocking over the first domino. Never mind that without the proper version of "hi, my name is" at the front of the message, the satelllite will think it is just noise- a packet with the wrong structure isn't a packet, computers are stupid. Too stupid to be fooled by something like this.

And more importantly, why would you want to do this?

I am not sure whether everyone understand what I mean. The concept is very simple.

From what I read SPOT lets you send 2 predefined messages. Say I enter some normal text. For HELP button: "I have some problems. SAR not needed." For OK button: "I am OK."
The person receiving the messages knows that "I have some problems. SAR not needed." = dot and "I am OK." = dash.

Then I start to transmit messages from wilderness. I want to send letter "C" which is _ . _ . in Morse code. I press OK button, then HELP button, then OK button and then HELP button.

When the recipient opens his/her mailbox he will see 4 new e-mails from SPOT device arranged by time of receiving (or creation):

"I am OK."
"I have some problems. SAR not needed."
"I am OK."
"I have some problems. SAR not needed."

The recipient translate it as:
_
.
_
.

which means _ . _ . and letter "C".

So this way he can decrypt whole words/sentences just from two kinds of e-mails. And I believe the decryption could be handled by some software that would process the e-mails and display directly (in this case) the "C" letter for the recipient.

Why would I want to do it? Well, it´s just an idea. I will probably never buy SPOT (PLB seems better to me) and I would rather buy satellite phone if I needed to communicate from the remote places. But for those who use SPOT and in some rare situation need to send some special message it could be useful. Or just for the fun of the "hacking" .

The problem with e-mail order is its not gaurenteed. e-mail queues up in a buffer and typically goes through anti spam and anti virus scanners which may delay processing of individual messages depending on how those process the threads. So that couple happen in this example is the longer of the two messages would take slightly longer to pass though so you culd end up with:
"I am OK."
"I am OK."
"I have some problems. SAR not needed."
"I have some problems. SAR not needed."

Or remember there are redundant and load balanced routes across the internet so some messages could go one route while others go another and the end result could be a completely different order.

The ther question is does the SPOT system have any debouncing. bouncing is inherent in anything electrical, take the kayboard of your computer for example. When you press a key on the keyboard there will be some noise or bounce as the key contacts makes its first connection. The electronics in any switch/button are designed with this in mind so once it sees the keypress it waits a fraction of a second to see if the key is still pressed. Now systems such as this work the same way just with a longer delay. They may wait a minute from the first receipt of the signal to see if its still transmitting, this would cut down the "oops I bumped the button" false alarms. I know if I were designing a system like spot I'd add in a minute or so delay just for that case. So you may need to stretch your dots and dashes out over a long period of time to get a message thorough.

Well stated. Those were my thoughts too, but you put it really well.

Morse code via satellite seems to be an inefficient use of the spectrum. One thing the folks at SPOT could do is add a few additional buttons to enhance the call for Help (not 9-1-1) so you end up with Help "A", "B" or "C". Allow the user to predefine what "A", "B" and "C" means to his/her email list. This would only apply to the "HELP" button.

The messages are time stamped so could in theory be reassembled to indicate a message. The SPOT device though has been designed to minimise the amount of Satellite bandwidth for eath SPOT device with the company running the SPOT system paying others for the satellite time.

I doubt whether the GPS position and the messaging information sent over the Satellite network would be more than 20 bytes in length. The GPS positional information and time stamp data could be sent using about 16 bytes. The SPOT unit serial number may be only 28 bits (3 Bytes and a Nibble) in length and the messaging system 2 bits with a couple of error correction bits (the other Nibble to make up the last byte). Overall the SPOT system isn't designed to send text messages but to just send the GPS and message data in the most compressed reliable format. Sendind a bit by bit message contained within the 20 or so byte format container packet isn't very efficient. The SPOT device is only capable of around 1900 messages before the batteries run out.

If composing an SMS text message on a possible future SPOT device then length of the text message would be around 140 bytes in length compared to the 20 or so bytes for each GPS update message currently sent. So one SMS text message will use the data bandwidth of around 7 GPS update messages. The designers of SPOT probably thought long and hard whether to include an SMS facility; the deciding factor was probably the overriding cost savings i.e. the initial market price point and the business model for the administration of the income stream or even the possibility that to gain access to the satellite network they had to demonstrate that the SPOT device would not specifically offer competition to SMS messaging services already available on the satellite constellation. It wouldn't take much to add a simple 1 or 2 line 16 character LCD display and a simple keypad to enter the SMS message into a future SPOT in addition to the current features. The problem then becomes the pricing mechanism to pay for the SMS messages.

e-mail is time stamped yes, but its time stamped several times so unless you look at the full smtp headers the time it arrived at your mailbox or mail provider can still be different than when it was sent.
I run into that a lot because my e-mail is trhough a small company I found in AZ and I'm in OH so the time zones and time stamps are always crazy, the times that show on on the mail someone recives from me will show some crazy time.

The device probably has logic to work with an intermittent signal. Which means it probably has buffer logic, and also since you're dealing with a satellite system, compression. So, instead of you sending out:

HELP
OK
HELP
OK
HELP
HELP
HELP
OK

Your message goes out as

OK - 3
HELP - 5

Not very useful.

That button on the front is for human interface into the logic on the chip. That chip is a "black box" to you. You have no idea what it does.

I think that the time stamp is actually the GPS time derived from the SPOT device. I've just had a quick look on the SPOT website and the update rates are set at about 5 minute intervals of the 911 type message and 10 minutes for the Tracking messages, so to send a message as described would have a baud rate about 0.0033 Baud (bits per sec) or to put it another way compossing a message length of 120 letters (average 4 bits/character) would take around 40 hrs to send. Perhaps someone should tell the NSA.

http://www.amfearliathmor.pwp.blueyonder.co.uk/morse_message.mp3

That´s interesting info, guys. Thanks. It seems to be more complicated than I thought. But if the original timestamp could have been read I think transmitting at least one word would be successful. The only way to find out is when someone who owns SPOT decides to try it. But I agree it´s not practical to communicate like this. It would be rather experiment for fun.

First of all, you have to assume the messages are recieved in the correct order. I'm not completly familiar with the Spot, but as I understand it, the messages are sent as emails which is a store and forward system and is queued on various email servers along the way. They may or may not be delivered in order.

Assuming they did come in order, for your simple example, it could also be "tete", "nn", "ke", "tr", or the beginning of "!". Add more characters and it becomes even more complex. With the absence of proper spacing between characters it would be difficult to make out what text you're trying to send.

I see someone already beat me to it, without someone on the receiving end knowing your touch on the keypad it would just come out ..---..--....-...-...-.....-..-...-...-...-...-....-....-

It could be solved. I would wait say more than 30 seconds before transmitting next character. The software processing and decrypting the e-mails would then recognize it from the time stamp and would add the spaces.

While this might even work, since the application is a nearly life-or-death usage relying on observed behavior of the system in a test or two might be rewarded by the system changing its behavior later when you need it the most.

Using undocumented features is hazardous to your intentions. (I've seen some computer designs fail in the field because designers used the performance they found in the sample parts but weren't in the spec. sheets for the production parts.)

I agree. If it wasn't designed to do it. Don't try.

Think about this: Denial of Service (DoS) attacks are common these days. The ground station that processes your message could stop listening to you because it thinks your device is malfunctioning.

Just trust Doug's short, but to the point message that it won't work. I've spent a great deal of time with SPOT's national sales people and worked with people that use SPOT and have me on their "friends" list. I am also familiar with Globalstar's satellite constellation that is used for SPOT messages. The reliability to send this type of message is just not there with the current technology. Understand that it can take sometimes 20 or 30 minutes for SPOT to get a single message to an orbiting bird. There is no way for you to know when the bird receives your message so it is impossible to time the next character for your morse code message.

I'm headed to the backwoods of Montana and Banff, Alberta this coming week and I will take a Globalstar 1600 which is very cheap right now due to reliability issues. I will not count on the 1600 for emergency communications, but use voice commuications for my "OK" messages. For emergencies, I will have an ACR MicroFix on my belt. Until SPOT moves into the area of text messaging, this combo gives me the flexibility I am looking for.

Craig.