SX-PY board is surely the easiest and most powerful GSM/GPRS remote control system that you can imagine:
it is based on TELIT GM862-PY modem with Python interpreter on board and
It encloses in a 9 DIN rail modules case: 2 optocoupled inputs, 2 relays outputs, an RS232 serial port,
a debug serial port, 2 expander connectors, backup battery with power fail detection and more�
The module is programmable with simple Python scripts to be uploaded through the serial port,
and it allows also users with no specific experience to easily realize remote control systems via GSM/SMS/GPRS.
And it�s not enough: this board allows to change the GM862-PY module with the GM862-GPS one that,
besides the described previous features, supports also a GPS receiver for localization applications.
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Hardware overview
Telit GM862-PY modems (you may find an application based on Telit modem in this article: How to execute a Phyton script with Telit ) are very powerful:
they, not only work very well as quad band modem, but also support a Python interpreter with 3MB Flash Memory and 1.5MB RAM,
2 serial ports and 13 input/output serial lines: just one problem is using the modem without a specific hardware capable
to support power supply and peripherals lines on the very small Molex connector.
SX-PY is the solution to these problems, a board developed with power and simplicity in mind:
in fact all the features of GM862 module are available, ready to be used in our projects.
The modem, as mentioned, may be programmed with Python script, a wide spread language and vary easy to use:
many dedicated web sites are available with all the needed information, e.g.
www.python.it or www.python.org.
Python interpreter onboard already supports all the library for hardware control (e.g. to send commands to the modem and to receive responses),
so allowing a fast use of all the features without any need of rewriting low level functions.
Programming the GM862 modem on board of SX-PY is executed through serial port, using AT commands:
to make this operation easier, Area SX provides also a free software with a simple graphical interface (SxPyDownloadTool :Python script management for Telit modem engines).
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Main features of the SX-PY board are:
- Filtered power supply in large range 9-15V AC/DC
- Backup battery (not included) connector with recharge circuit
-
- Power fail detection
- Battery left charge level retrievable in Python scripts using AT commands
- GPS receiver (available using only GM862-GPS module)
- RS232 Serial port for script upload
- RS232 Serial port for script debug
- 2 optocoupled and configurable input lines
- 2 relays output (48V/2A)
- Flex expander for SX16B board (SX16B - IN/OUT expansion board) to enlarge inputs and outputs number
- Expander for proprietary hardware connection
- Connector for RF serial module ER400TRS (Trasmissioni in Radiofrequenza facili con Easy Radio)
- Reset button
- Test button
- LEDs for power, battery charge, GSM network, RF data transfer and test
Hardware detail
All the peripherals and interfaces on board are well designed, in particular some of them deserve a more accurate view.
Power supply section
Power supply section supports a wide range voltage both DC and AC and a strong filter.
This allows a very good noise rejection that may pass on power line because of electromagnetic interference.
This section is completed by a connector for backup battery with related recharge circuit;
battery charge level and power supply status are directly monitored by modem AT commands and so available in our scripts.
When power supply fails, backup battery automatically works; power is ensured to modem and, optionally, to expander bus
while the remaining hardware is turned off: in this condition the device may work for 36 hours and more.
Inputs and outputs
The two inputs on board may be configured one different from the other.
In particular it is possible to use completely optocoupled inputs supporting also no-polarized voltage or voltage-free inputs.
Relays outputs can drive loads with voltage up to 48V and peak current of 2A.
DCE Serial
On the standard 9 pin female connector you find a complete serial port, straight connected to the modem.
Using this serial port, you can control the modem from external application and upload Python scripts.
Debug serial
Above all the features, one very important to easily use a programmable system is surely the chance to have a debug interface for your source code.
SX-PY board supports this feature with debug serial port that allows to control script running during a test phase.
This serial port is placed on a 5x2 pins connector to be used with a flat cable with a crimped serial connector.
RF serial and expanders
Board equipment is completed by a RF (433MHz) wireless serial slot and two expander connectors:
the first allows a straight link to FLEX interface boards, such as SX16B, as mentioned before (SX16B - IN/OUT expansion board)
or FLEX Analog (FLEX-Analog: an analog acquisition board with flexibility in mind!).
The second allows the proprietary hardware connection, supporting 8 input/output lines and power supply line;
this one may be both +5V or +3.7V with backup power supply from a battery to ensure reliability.
Input and output expansion
SX-PY board has a connector for straight link to SX16B board (SX16B - IN/OUT expansion board):
this way 24 inputs, 6 relay outputs and a temperature sensor ara available for Python scripts control.
Moreover, since SX16B is very flexible and scalable, you can connect several boars in a cascade configuration
to realize a further input/output expansion.
You can use the same connector to link FLEX Analog board (FLEX-Analog: an analog acquisition board with flexibility in mind!) to support 8 A/D inputs and 2 D/A outputs with 8 bit resolution.
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Cases
SX-PY board, as the SX16B one, may be placed in a 9 modules DIN rail case.
This makes the board very suitable to be used in electric panels to realize remote control systems,
surveillance and automation in houses or industrial environments.
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Test scripts
How to use the SX-PY board
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Tags: - Python - Schede Area SX - Telecontrollo -
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