TC65 with ccs

[Tom1234]

I would like to program a TC65 module via dspic33 microcontroller. Can i find any sample about what AT commands  need to use?

also if i use the AT commands of the TC35 would it be ok?

[motox]

Five years ago I did a project with a TC65 modem and a PIC24 using C30.
The code is property of my employer, so I cannot give you the complete project.
But sure I can help you out.
Let me first explain what I did. In my project I have a PC with a LabVIEW program that opens a specific TCP port (server). The TC65 is at a remote location and when it wants to send data, it connects to that TCP/IP port and sends the data. After that it closes the connection and goes to sleep.

I implemented the necessary functions to initialize, Request SIM Credit balance, get signal strength and channel bit error rate, connect to a specific TCP port in a specified IP address, disconnect, read TCP data, write TCP data, send AT command and finally shut down.
All of this using state machines. The PIC never waste time pooling events!

There is something very important, you should always analyze every response from the modem, specially the asynchronous error responses (AKA Unsolicited Result Codes) if you want to make a robust project.
The problem is that there are a lot of different type of responses, so this is not an easy job.

The modem has hundreds of commands (never counted them). So first decide what you need to do with it. Then make an ordered list of the commands that you need to execute to perform each step. I can tell you all the essential commands if you just want to do what I did in my project.

As an example, here are some commands to stablish a GPRS connection in Portugal (these may change on a different country):

Code:

AT&C2				// Enable signal DCD
AT^SICS=0,conType,GPRS0
AT^SICS=0,apn,internet
AT^SISS=0,srvType,socket
AT^SISS=0,conID,0
AT^SISS=0,address,"socktcp://192.168.1.1:1000"	// Put the IP address and TCP port number
AT^SISO=0					// It takes between 3 s to 6 s to reply "OK"

Session info: AT^SISI?<CR>
Close session: AT^SISC=0<CR>
Request SIM Credit balance: ATD*#123#;

[Tom1234]

Thanks a lot for your respond.

I am trying to create a tracking vehicle system, so the gprs connection between TC65 and server is a priority.

First, i would like to ask, how do you connect the pic with tc65(actually is TC65i, I2C,UART,SPI??? ) and what is the minimum frequency which is needed for the microcontroller.(i mean what s the frequency from the crystal).??

[motox]

I used the UART interface.
See part of the schematic bellow.

[Tom1234]

Why you use two different crystals?Also what is J7 is this the TC65?

[motox]

Yes, J7 is the connector for the TC65. My TC65 (non i version) has RS232 levels.

X1 is the main oscillator, X2 is the low power oscillator for the real time clock. X2 is always enabled even during sleep.
The complete system is powered by a battery and a solar panel.

You can use almost any oscillator frequency.
I'm using the TC65's UART at 9600 bps. Which is a very slow baud rate.

Here are some more useful commands (only need to send once if you save the config in memory):

Code:

AT+IPR=9600			// Set UART baud rate
AT\Q3				// Flow control
AT^SCFG="Tcp/WithURCs","off"	// Disable Internet Service URCs (Unsolicited Result Codes)
AT&W				// Save current config

[Tom1234]

what do you mean with the function  for "Request SIM Credit balance, get signal strength and channel bit error rate"

I am looking for a schematic of the module something with a clear view of the pins.

[motox]

Signal strength is similar to the 5-bar phone signal in your cellphone. It represents the received power level of the wireless signal.
Bit error rate is the quality of the reception.
These are different things, e.g. you can have a strong signal but with lot of noise.

SIM credit balance is the available credit in your card. This only applies to prepaid cards. Probably the code *#123# only works in Portugal. But you should find a similar code in the country.

Extra info:
Did you know that prepaid cards were invented in Portugal by TMN in 1995! 

[Tom1234]

How to create a function for test the "Signal strength" and "Bit error rate"  ?

look like little difficult to me.
can you give me more guideline

[motox]

To execute a command just send it through UART. In case of the signal quality the command is: AT+CSQ. The TC65 will reply those values through UART.

Document “AT Command Set”, version 2.000, page 202:
8.5 AT+CSQ Signal quality
The  AT+CSQ  execute command indicates the received signal strength  <rssi>  and the channel bit error rate <ber>.
Syntax:

Code:

Exec Command:
AT+CSQ
Response(s):
+CSQ: <rssi> , <ber>
OK

Can you connect your TC65i to a USB-RS232 converter?
The easiest way to test the TC65 is using a PC with a terminal program to send the commands manually.

[Tom1234]

I don't have the module yet.(I will have it in the week ).

Btw i checked your schematic and i think something is going wrong.

for example  pins 1and 4 are the gnd (for tc65i module) but in your schematic you connected these pins to R2IN and T2OUT of the rs232 Transceiver.

something wrong or  i don't understand something?

[motox]

TC65 and TC65i are different.
J7 is a double row connector for flat cables (like the IDE connector). That cable connects to the DB9 of the TC65 (see attached picture).

[Tom1234]

I am thinking something like this :

http://uk.farnell.com/mc-technologies/tc65i-x-gpio-terminal/mod-quadband-gpio-java-terminal/dp/2250671


what do you think?

[motox]

I cannot find the data sheet of this version with the external connections.

Personally I think the TC65 it’s too expensive. You can buy much cheaper options.

For example, something based on the SIM900 from SIMcom.
$35: http://imall.iteadstudio.com/im140318007.html

[Tom1234]

I prefer to stay to TC65. what is the best module for this device?

[motox]

It’s difficult to say, I guess they are all good. You just have to find the one that fits most to your application.

[cncbasher]

you dont say if this is a hobby or a commercial project ,
iv'e done quite a lot of gps tracking systems over the years , so it depends on the level you want to work at
but take into consideration airtime fees , and connection times to a minimum , in the early days we used the sms control channels
as it was the cheapest for cost .

this may be of some help , in the meantime
http://people.ece.cornell.edu/land/courses/ece4760/FinalProjects/s2012/bdt25_edr46/bdt25_edr46/

[Tom1234]

motox,  i need to find a complete module with good documentation for TC65 just to program the TC65.
(I start to think to use the module that you used. i can found a lot of datasheets).

This is my first commercial try , i feel little confused

[LzEn]

The link you posted to Farnell shows the price @ £175.02. This is way too expensive for any commercial gps system. Unless there is something I am missing.

[Tom1234]

I was thinking to use this module for programming /testing the TC65 module and then to move to something more cheaper(with TC65). Or event better to buid a pcb using the tc65

[LzEn]

If you are familiar with C programming I would recommend to you Quectel modules with OpenCPU technology. The concept is that you buy the GSM module from Quectel and then you can write your own application using GCC tools and flash it to the module itself. That way you do not need any external components everything is built-in.

Also since you were asking before about Over The Air upgrade, the OpenCPU provides FOTA(Firmware Over The Air) feature using the provided SDK.

Here is a snippet from their website:

●  Reduce the product development period.
●  Simplify the circuit design and reduce the cost.
●  Decrease the product’s size.
●  Decrease the power consumption.
●  Upgraded via OpenCPUTM FOTA.
●  Enhance the intellectual property protection with the Anti-copy technology.
●  Improve the performance-to-price ratio and enhance the competitive strength.

And here are some related links:
* LINK
* LINK
* LINK

I know the above is not directly your approach, but you might want to give it a look.

Regards

[Tom1234]

I choose this module beacuse of java integrated. With this feature the  "Over The Air upgrade" willbe more easy . (I think)

[motox]

My advice is to buy something like this:
http://www.aliexpress.com/store/product/SIM968-C-Quad-Band-GSM-GPRS-33tracking-99-acquisition-channel-GNSS-receiver/605000_1954238087.html

For 23USD you get a GPRS modem with a GPS/GLONASS receiver.
For the upgrades, just integrate a simple serial flash upgrade routine into your program.

[LzEn]

My advice is to buy something like this:
http://www.aliexpress.com/store/product/SIM968-C-Quad-Band-GSM-GPRS-33tracking-99-acquisition-channel-GNSS-receiver/605000_1954238087.html

For 23USD you get a GPRS modem with a GPS/GLONASS receiver.
For the upgrades, just integrate a simple serial flash upgrade routine into your program.

Actually SIM has a GSM module with integrated GPS and it is cheaper than the one provided in your link. It is called SIM908 and here is a LINK if you want to check it out.

But Tom is looking for something with Java support, so these options are out.

[Tom1234]

Guys i would use the TC65 (TC65i).
I am not searching for any other module.
so please give me any suggestion regarding this GSM module.