Perhaps the biggest advantage to using a commercial modem with the phone service is that you get a "Part 68" pre-approved DAA with it and don't have to worry about FCC regs as a consequence.
Yea, I am just trying to make a buck. I don't want to have to worry about guys in trench coats kicking my door in and dragging me off to jail. Or slapping a fine on me that I would be unable to pay.
This is a different solution to the problem, but I use an xport to send tcp data to a server. I wrote a service to text my phone with information via our mail server. I haven't had any problems and it keeps everything "under my roof".
A fellow Hoosier, pleased to meet you 101. As I previously mentioned, I am trying to avoid tying my machine to a computer, but I might end up doing that. Do you have any source code that you would be willing to share?
Bruce, thinking laterally from the above posts. You can buy a modem cheaply which of course comes pre-approved to connect to the PSTN (public switched telephone network = phone network).
So, You can easily have it dial you cellphone. So, now what you need to do is program a simple command set to the modem. A modem can be used to take the line off-hook and dial - they were used as autodialers at one stage.
So, "ATH1Dnnnnnnn..." go off-hook and dial your cellphone and wait. Obviously it will not connect to a modem
Now here is where my memory fails... Once the other end answers you need to know and the modem drops back to command mode
Now you issue "ATD111,,,111,,,111" dialtone - 3 sets of 3 tones with 6 secs gaps between them. This is error 3 - you get the idea. You may find a different digit sounds better but the ear cannot easily detect the different tones (yes some people can detect all the digits reliably).
The hangup "ATH0"
Hope this gives some further ideas.
One thing to remember is that the SMS network is not a guaranteed message response time. That is, we have received SMS occasionally that have been delayed for hours. Not often but it happens. IIRC, with the dialing method above, you can detect an answer vs busy and no connect.
Bruce: You should be able to find someone with a modem lying around. I am pretty sure this will work and it's easy to try using a pc connected to the modem and a terminal program such as HyperTerm of equivalent. In its window do the following (say at 9600 baud)
(search for the Hayes AT command set for definitions)
ATH1DTxxxxxxxx;<cr> where AT=attention to the modem, H1=go off-hook, DTxxxxxxxx = dials your number xxxxxxxx using tone, ";" you will have to check returns to command mode when the phone answers, and <cr> is the enter key.
When connected you should see "CONNECTED"
(I do not think you need to do "+++" to return to command mode - note this must be IIRC 1 sec delay then type +++ within 1 sec each then delay 1 sec (do not hit enter))
ATDT111,,,111,,,111;<cr> where "," is a 1 or 2 sec pause, unsure about the ";" You should hear the tones dialled
(as above, I don't think "+++" is required)
ATH0<cr>
Now I think that could all be placed in one string provided the "+++" is not required, so
ATH1DTxxxxxxxx;DT111,,,111,,,111;H0<cr>
may work. I cannot remember if ";" is required. I wrote modem code which implemented the AT command set in the 80's.
I once bought a US Robotics 56K modem that had outstanding documentation. In fact, it pretty much let you write your own driver for it in a batch file, if you were inclined to do so. I will have to look for that. Anyhow I have this old credit card machine that I have been scavaging parts from and it has a modem and all the necessary components, but then I lack the documentation. I definitely appreciate your input on this.
When Parallax was smaller and I had more freedom I liked experimenting with communication hardware including the Cermetek line of modems. Because my laptop had a modem I was able to connect to my home's radiant heat system when I was out for business travel - the Tekmar control system had a nasty bug that was causing a heat overdrive in the floor and I was able to turn the boiler off remotely when things were getting out of control. We made a fairly successful AppMod product from the CH1786 for PC<=>microcontroller or microcontroller<=>microcontroller communication. This product was really easy to use but it was eventually discontinued due to a high manufacturing cost, a format dependent on a certain header on our boards and low margin.
If it turns out that their devices are useful for your project I'd also be interested in talking with them about a product for our microcontrollers. Their devices were easy to use, well-supported, but a bit costly in low volume. However, a lot has changed in their market and there are so many more choices, just like everybody identified above.
When Parallax was younger I had the luxury of experimenting with a variety of hardware.
I can only imagine. I have been visiting parallax for several years now, only recently have I become actively involved in the forums. Anyhow, I have seen a lot of interesting hardware come and go through your online store. A lot which has been discontinued, but I wish it was still there. As I mentioned in another post, I wish I would have purchased one of those HP Ink Jet modules you had, as well as the modem module. You never know what you are going need, even when it is looking straight at you. And you ought not tease me with the photograph of a goodlooking modem module:) Look at the corners on that beauty.
Where it stands now, I am leaning toward a modem that just leaves a certain number of beeps. As mentioned earlier in this post, with the machines I am building, there is currently only one attachment outside the machinery. And that is the necessary attachment to a 120V outlet for my power supply. I am trying to keep as simple as possible to avoid additional reoccuring costs. I don't know where the machine will find it's resting place, but I can reasonably assume that it will have access to a phone jack. Whether or not internet service will be able, that I cannot say for sure one way or the other. Of course I am being stubborn, because to me the simplest solution would be to have a serial connection to a pc, and have a C++ program monitor the serial port for information and send out an email when an error occurs. There is plenty of C++ documentation online for PC serial port communication. But that would mean that I would have to have the machine tied to a PC.
I will be calling Cermetek tomorrow sometime and discussing my situation with them, as well as the attachment to the Propeller IC. I want to hear what they have to say and to find out what kind of customer support they have. I will be more than willing to tell you what was discussed and how I plan to proceed. However, I am just gathering information now. My main goal is to get to the point of being able to reliably produce my product.
I was thinking of using a propeller and an x-band detector in the office, connected to the LAN. We have guaranteed paid SMS service, activated via e-mail. An e-mail modem looks perfect..
Massimo
Be careful about legal requirements. There is a safety issue. I took a look at the Cermetek site and there are about 4 DAA modules that have Registered status. However, there are certain requirement which must be met by the user before the Register status may be transferred. Unless you are aware of the obligations, it is not just a matter of sticking it on a pcb.
Thanks for the advice. I always try to read the legal fine print (except for website usage policies). That is most certainly good advice for anyone contemplating adding it to a circuit board, however in my situation, I will not be distributing DAA or modems, at least not in the immediate future. Actually I was thinking of keeping it seperate and near the phone jack, that was my thought. I have not contacted them today like I previously said I would, but I will definitely contact them tomorrow. Anyhow, please keep up with your other post, I definitely have an interest in it. Who knows what will happen once I actually get my PCB driller running. I will probably stick to stepper motor drivers, but who knows.
Comments
-Phil
Yea, I am just trying to make a buck. I don't want to have to worry about guys in trench coats kicking my door in and dragging me off to jail.
Bruce
A fellow Hoosier, pleased to meet you 101. As I previously mentioned, I am trying to avoid tying my machine to a computer, but I might end up doing that. Do you have any source code that you would be willing to share?
Nice looking ride.
Bruce
So, You can easily have it dial you cellphone. So, now what you need to do is program a simple command set to the modem. A modem can be used to take the line off-hook and dial - they were used as autodialers at one stage.
So, "ATH1Dnnnnnnn..." go off-hook and dial your cellphone and wait. Obviously it will not connect to a modem
Now here is where my memory fails... Once the other end answers you need to know and the modem drops back to command mode
Now you issue "ATD111,,,111,,,111" dialtone - 3 sets of 3 tones with 6 secs gaps between them. This is error 3 - you get the idea. You may find a different digit sounds better but the ear cannot easily detect the different tones (yes some people can detect all the digits reliably).
The hangup "ATH0"
Hope this gives some further ideas.
One thing to remember is that the SMS network is not a guaranteed message response time. That is, we have received SMS occasionally that have been delayed for hours. Not often but it happens. IIRC, with the dialing method above, you can detect an answer vs busy and no connect.
One thing is certain, I will get a modem that has very good documentation. And hopefully good customer support.
Bruce
(search for the Hayes AT command set for definitions)
ATH1DTxxxxxxxx;<cr> where AT=attention to the modem, H1=go off-hook, DTxxxxxxxx = dials your number xxxxxxxx using tone, ";" you will have to check returns to command mode when the phone answers, and <cr> is the enter key.
When connected you should see "CONNECTED"
(I do not think you need to do "+++" to return to command mode - note this must be IIRC 1 sec delay then type +++ within 1 sec each then delay 1 sec (do not hit enter))
ATDT111,,,111,,,111;<cr> where "," is a 1 or 2 sec pause, unsure about the ";" You should hear the tones dialled
(as above, I don't think "+++" is required)
ATH0<cr>
Now I think that could all be placed in one string provided the "+++" is not required, so
ATH1DTxxxxxxxx;DT111,,,111,,,111;H0<cr>
may work. I cannot remember if ";" is required. I wrote modem code which implemented the AT command set in the 80's.
I once bought a US Robotics 56K modem that had outstanding documentation. In fact, it pretty much let you write your own driver for it in a batch file, if you were inclined to do so. I will have to look for that. Anyhow I have this old credit card machine that I have been scavaging parts from and it has a modem and all the necessary components, but then I lack the documentation. I definitely appreciate your input on this.
Bruce
Hopefully this will aid you and others as this has progressed to what could be a nice function for others too.
When Parallax was smaller and I had more freedom I liked experimenting with communication hardware including the Cermetek line of modems. Because my laptop had a modem I was able to connect to my home's radiant heat system when I was out for business travel - the Tekmar control system had a nasty bug that was causing a heat overdrive in the floor and I was able to turn the boiler off remotely when things were getting out of control. We made a fairly successful AppMod product from the CH1786 for PC<=>microcontroller or microcontroller<=>microcontroller communication. This product was really easy to use but it was eventually discontinued due to a high manufacturing cost, a format dependent on a certain header on our boards and low margin.
After it was discontinued I started working with their e-mail modems, http://www.cermetek.com/catalog/Embedded-Device-Servers/DataSheet/index.htm?http://www.cermetek.com/catalog/Embedded-Device-Servers/DataSheet/CH2160_607-0017/ - the CH2160. It also supported a simple serial interface for sending and receiving e-mail. I'm wondering if e-mail through a dial-up ISP would be a solution for you. Though you need an ISP the coding is really easy.
If it turns out that their devices are useful for your project I'd also be interested in talking with them about a product for our microcontrollers. Their devices were easy to use, well-supported, but a bit costly in low volume. However, a lot has changed in their market and there are so many more choices, just like everybody identified above.
Let us know how it works out.
Ken Gracey
Parallax Inc.
I hope life is treating you well.
Where it stands now, I am leaning toward a modem that just leaves a certain number of beeps. As mentioned earlier in this post, with the machines I am building, there is currently only one attachment outside the machinery. And that is the necessary attachment to a 120V outlet for my power supply. I am trying to keep as simple as possible to avoid additional reoccuring costs. I don't know where the machine will find it's resting place, but I can reasonably assume that it will have access to a phone jack. Whether or not internet service will be able, that I cannot say for sure one way or the other. Of course I am being stubborn, because to me the simplest solution would be to have a serial connection to a pc, and have a C++ program monitor the serial port for information and send out an email when an error occurs. There is plenty of C++ documentation online for PC serial port communication. But that would mean that I would have to have the machine tied to a PC.
I will be calling Cermetek tomorrow sometime and discussing my situation with them, as well as the attachment to the Propeller IC. I want to hear what they have to say and to find out what kind of customer support they have. I will be more than willing to tell you what was discussed and how I plan to proceed. However, I am just gathering information now. My main goal is to get to the point of being able to reliably produce my product.
Bruce
The prices start at $10.
Cheers
Massimo
I would have to agree. For a much simpler setup, a DAA would be the ticket.
Bruce
Thanks for the advice. I always try to read the legal fine print (except for website usage policies). That is most certainly good advice for anyone contemplating adding it to a circuit board, however in my situation, I will not be distributing DAA or modems, at least not in the immediate future. Actually I was thinking of keeping it seperate and near the phone jack, that was my thought. I have not contacted them today like I previously said I would, but I will definitely contact them tomorrow. Anyhow, please keep up with your other post, I definitely have an interest in it. Who knows what will happen once I actually get my PCB driller running. I will probably stick to stepper motor drivers, but who knows.
Bruce