Telit GSM/GPRS breakout for Propeller proto board
Tubular
Posts: 4,703
This board lets you connect your propeller proto board to the internet using 2G GSM / GPRS.
It uses the newish Telit GE865 which has a great "easy GPRS" command language for doing routine tasks such as sending sms or email, sending files via ftp, and connecting to http servers.
I cheated a bit and made the pcb extra thin so that the ball grid can be manually soldered from behind, by poking the tip of the iron into each 'well'. This will keep the costs right down, as the GE865 is currently Telit's cheapest form factor.
Some other features
* Optional RS232 using MAX3232 for easy setup/debug using USB<>Serial dongle
* Linear LDO reg on board, adjustable voltage setpoint and load point sense wire
* Status led blinks at different rates to indicate connection status
* 10 pin connection to P0-7 and Power on proto board
* Several telit GPIO broken out on top 0.1" header row.
* MMCX antenna connector, MMCX to SMA cables readily available.
PRICING:- See post below
It uses the newish Telit GE865 which has a great "easy GPRS" command language for doing routine tasks such as sending sms or email, sending files via ftp, and connecting to http servers.
I cheated a bit and made the pcb extra thin so that the ball grid can be manually soldered from behind, by poking the tip of the iron into each 'well'. This will keep the costs right down, as the GE865 is currently Telit's cheapest form factor.
Some other features
* Optional RS232 using MAX3232 for easy setup/debug using USB<>Serial dongle
* Linear LDO reg on board, adjustable voltage setpoint and load point sense wire
* Status led blinks at different rates to indicate connection status
* 10 pin connection to P0-7 and Power on proto board
* Several telit GPIO broken out on top 0.1" header row.
* MMCX antenna connector, MMCX to SMA cables readily available.
PRICING:- See post below
1024 x 932 - 79K
996 x 662 - 192K
1024 x 586 - 76K
Comments
I use the older style Telit modules, myself, and must say you have done a very nice job here using the new form factor.
CONGRATS!
Selling any?
Cheers,
Peter (pjv)
I've been using various GC864 modules in commercial products, and Sony Ericsson GR64 before that. They are good solid devices no question about that. I got some extras run and are selling them in kit form, also an Arduino GE865 version (same kind of concept)
When I started with the telit there was a real lack of breakout boards that say brought out the ADC and DAC pins. There were EVK2 boards but very pricey. We're a bit spoilt on the prop forum with people designing boards for all manner of applications, but despite Telit's millions of sales its not easy to get good breakouts. No wonder Sparkfun are growing...
cheers
Lachlan
i just found your post whilst googling telit Breakout.
I am using a GC864 with an arduino based board. I am very much in need of a breakout for the GC864 if you have one. I need about 20 of them, name your price!!
cheers
andrew
That trick of soldering the BGA from *below* is brilliant!
This is one of the reasons why I log onto the forum every day ...
Thank you,
T o n y
Hi Andrew, welcome to the Prop forum.
I don't have an equivalent breakout for the equivalent '864 (GE864), unfortunately. I have worked with the GC864 but decided to cut straight to the GE865 and avoid that fine pitch 80 way molex connector.
If you can use the GE865 instead of the GC864 then I can help...
cheers
Lachlan
Thanks Tony,
Just realized I didn't post a pic of the rear side, unbelievable. Here goes...
PS; The SIMCOM900 module comes already soldered on a board that you can re-flow using a small oven.
JMLStamp2p
I see no reason why the GE version would be unacceptable so yes. I would love to hear more about this.
righto
andrew
Pricing for 20 off would be as follows (for the Propeller PCB version, for use with Proto board or similar), available ex stock
$ 9.00ea for the PCB only
$64.50ea for the GE865 module by itself.
$ 5.00ea for the MMCX to SMA adapter leads if required
I am assuming you would would to assemble these yourself, and source the remaining components (which are relatively easy to obtain). There are at least 3 linear LDO regulators that can be used.
There is a arduino version in the pipeline, if you really need it lets talk on PM.
Lachlan
JMLStamp2p,
I don't know a lot about that SIMCOM series, haven't seen them in the market here. Please tell me how you have found it to use, and approximate pricing.
As these things sometimes go, using Telit really more about support than pricing. Several years back I was using Sony Ericsson, then they got bought by Wavecom and discontinued (or "morphed" in a newer more complicated beast) the module I was using. Telit manufactured a kind of clone that worked effortlessly, so we went with that. I've been very happy with the Telit modules. I think Telit is purchasing Motorola's M2m division so again happy to be on the 'side of product continuity'.
What is this trick for soldering "from behind"? How does it work? And for the GE865 antenna connector? I am very interested in using this board and soldering it myself. Is the Arduino version already available?
How did you solve the logic level difference? Tx and Rx on the GE865 are 2.8 V right?
Where can I order the shown PCB?
Thanks in advance for your answers.
Best wishes,
3dotter
The GE865 has "solder bumps" (half balls) underneath it, on a 2.4mm pitch 8x8 grid. There bumps are about 1mm diameter. My pcb has plated through holes that are slightly larger to accommodate the bumps. So to assemble, the GE865 is placed on table with bumps facing upwards, and the thin pcb is placed over the top. Then you just go over each "plated through well" (which has a GE865 solder bump at its bottom) and melt the solder ball so it solders to the wall of the "well". The PCB is very thin, about 0.7mm, and this permits a fine tip iron to easily make contact with the solder ball itself.
The antenna is just another bump that is soldered the same way, and it connectors to a MMCX connector a minimal distance away.
The arduino version is getting proto'd now, it'll be a little while until I have production boards in that format. I have matching prop boards available now
The easiest way to deal with the level shifting is run the Prop or other mcu from 2.9~3.0 volts DC. Sure it involves another adjustable regulator but thats simpler than level shifting. The arduino version has a couple of quad level shifters on board so it can have a 5v rail happily.
Just PM me if you want to purchase, $10 per board plus something very miniscule for postage
Thanks again for the boards. They're beautiful.
Okay, I think I'm in over my head with this project. I'm afraid I'm going to need a lot of help.
To start with, I don't know which components to use with the voltage regulator.
The voltage regulator you sent me looks like it's a different one than the regulator in the picture in the first post.
I'm attaching the datasheet to these NCP5663 regulators. (In case other forum members are interested in this.)
I see in figure 1 on page 5 the resistors R1 and R2 should be chosen based on the equation:
R1 = R2((Vout/Vref) - 1)
Figure 1 shows Vref is 0.9V. I don't know what voltage I'm supposed to use for Vout.
The information at the Telit website states the "Nominal Supply Voltage" is 3.8V. Is this Vout?
I think I can make out the value of R1 and R2 on the first post's picture. They look like they are both 47K Ohm. Is this correct? Can I use these same values with the NCP5663 regulator?
On to the capacitors. The regulator datasheet mentions the importance of low ESR (equivalent series resistance IIRC).
The input capacitor should be 150uF with a ESR of 50mOhm. An OSCON capacitor is recommended. Wikipedia tells me an OSCON capacitor is a Sanyo polymer capacitor. It looks like you used an electrolytic capacitor on your example board. Do I need to worry about this much?
The datasheet says the output cap should be greater than 33uF with an ESR of less than 300mOhm.
I just looked through my caps. I probably have a tantalum I could use for the output cap but I don't have any 150uF so I'll probably be placing a Digi-Key order soon. Any suggestions on which caps to use with the NCP5663 regulator?
I'll probably use your suggestion of powering the Prop somewhere between 2.8V and 3.0V so I don't have to worry about level shifting the logic lines.
I'm thinking of using one of these switching regulators to power the Prop. I've had trouble with interference when I've used a similar 3.3V regulator to power a 2.4GHz RC radio. I wonder if I need to worry about interference from a switching regulator with the Telit module.
Sorry for asking so many basic questions.
Are there other forum members using these boards?
Duane
A couple of quick responses before I head out for a short while:-
1) Switching reg's with Telits are a challenge. I really suggest starting with a 3A LDO until you get your application running, then cut over to a switcher and make sure it doesn't introduce new problems. If you must go to a switcher straight away, you can copy the Telit suggested 12v switcher circuit
2) Re the setpoint, yes 3.8v to 4.0v is the normal operating voltage for these. They have sharp current spikes so you want to get well above the 3.4v minimum so these spikes don't trigger resets etc. Logic level is 2.8v (and some 1.8v) regardless of the 3.4~4.2v supply voltage (normally a LiPo battery)
3) In the photo, one of the resistors is 47k, the other is two resistors stacked with a 47k shown on top trimming. There is another resistor underneath. I would aim for about 4.0 volts as a starting setpoint, allowing a bit of drop from a 5v power supply, but plenty of headroom above the 3.4v minimum.
4) I have used a 100uF low ESR electo just fine for the regulator output cap. But my boards have generally used the LT regs thus far. I'll build one with the 5663 and see what issues present.
im now developing propane gas sensor. and i would like to find a way to send signals to alert people by using sms. i just wanna send a simple sms or email message to warn me about the gas leak.
i just wanna ask if this telit GE865 is compatible with parallex board as picture below? and can i program the telit GE865 by using basic stamp?
Thanks for any help
Yes, should be easy to instruct using a basic stamp, since the GE865 is controlled by "ttl serial".
However you will need a larger power supply that can supply more amps than you would normally use with a basic stamp, because the GE865 can consume up to about 1 amp of power (so its better not to take it via the regulator on the board you showed, but from a separate supply).
Any other questions, please ask.
cheers
tubular
I am new to the Propeller and need advise on weather to approach this project using GCC or with Spin.
I thought of the Propeller due to it's Parallel processing capabilities, thought there would be less timing issues with the end product. I will be incorporating various sensors within the project in an Industrial environment.
Any advise and Code examples toget me darted in the Right Direction would be very much appreciated!
Thank you,
John Michael
The prop really shines with multiple high speed sensors in industrial environments.
cheers
tubular
I am really excited about learning to use the propeller with Industrial controls. I have a Professional Dev. Board for the propeller and using BST with my Apple Computer, thought the Integrated Terminal Program might be an advantage.
John.
Also, they are stateing in the Hardware manual for the 865 to use a 47K pull-up resistor on it's rx_UART line due to no internal pull-up. I have never used these voltage levels before, used TTL in the past and not sure of the best approach to interface these two componets. What would you recommend ?
Thanks,
John.
Here's a couple of strategies in order of "most formal" to least / simplest
1) Use a bidirectional auto level shifter, eg the TI TXB0108, or the Analog Devices ADG3304. Most flexible if you need to be able to run with any voltage rail 1.8..5.5v, LiPo etc
2) Use the single direction level shift as shown in the Telit Ge865 Hardware documentation
3) Run the Prop from 2.7~3.0 volts instead, and connect directly. 0.2v difference shouldn't cause trouble with substrate diodes etc. Depends on what else is connected to the prop
4) Simple series resistors. Seen this done for plenty of 5v<>3v3 circuits, a 1.7v differential, and here you only have a 0.5v differential. Should work fine but I haven't tried
When I have two chips operating at different Voltage levels like I do with the TeLit (2.8V) and the Propeller (3.3V), are the RS232 serial Voltages levels the same due to the Max232 chips or are they different with respect to the Supply Voltage?
Second, Can you Clarify on the Tx and Rx wiring from the TeLit to the Propeller. The way I read the doc's it appears that I would go from (Tx) on the TeLit to (Tx) on the Propeller, same with the (Rx) lines. In the past I have always had to do the (Tx) to (Rx) thing ...
What I'm wondering is this: Since I'm using a Professional Development Board with a Built in 9-Pin Serial and a Quad 865cf Eval Board; can I just go from one to the other via Standard Serial Cable without having to adjust circuitry?
Also understand that TTL Logic level's are: +2V to +5V (for High) and (0V to +0.8) for Low. But I have never had any experience with anything else ...
JM I think when you have the same equipment you actually need the null modem cable, and when you have DTE<>DCE you need the staight through cable.
In any case its possible the PDB could be designed as DCE (so it connects straight through to DTE) or as a DTE (to act like a PC).
The quick way to check is to grab a led (with series resistor) and, with both devices turned on but not connected, check whether each is transmitting on pin 2 or 3 (with the other end of the led/resistor combo on pin 5 ground). If you don't use a bicolour led you might need to flip the led to get the right polarity If both devices are trying to transmit on the same pin, you need a null modem cable to cross them over
hope this helps
regards
tubular
A straight thru cable was normally used for DTE to DCE, with the whole 25 wires used. However, later cables with less wires were used. When a DTE to DTE connection was required, because of varying implementations in mainframes and minis and the terminals they were connecting to, various crossover cables were designed specifically for the task at hand. Typically, a lack of understanding of the specifications led to many incorrect crossover designs.
Then came the IBM PC, complete with correct DB25M for the serial interface. BUT, they used the DB25F for the printer - a new confusion emerged. Later, when space became an issue, the DB9 was used on the PC, and later the minidin8.
Hope this gives you a little insight.
BTW "Feel Like I'm talaking to myself :>)" is not a good way to get an answer. Remember, not everyone can answer, and in particular, this thread is not read by everyone as it is quite specific. Also, tubular and I are in Australia, so we are often asleep when you post.