Concept Board, Send SMS when power shuts down | Telit Cinterion IoT Developer Community
October 17, 2017 - 10:24am, 5433 views
Hello,
I would like to create an application, that sends an SMS to inform the user that the power supply on which the concept board is attached too, has shut down. My initial thought was to connect a condenser that can read the current in the A/D converter, and when that value reaches zero, it starts the "send SMS" application. However, i have not been able to find the pins for the A/D(by this i mean the Vbatt+ and Vbatt-). Have i simply missed them in the schematics or are they not available, and if not, is there another way to construct this application?
Thankfull for any help, Willie
Hello,
You will find the BATT+ line in the top right corner of the Concept Board. There are also ADC inputs on the bord. Please not that the 4 ADC channels on the board are multiplexed to one EHS6 ADC channel. Choosing one channel out of four can be done either by the Control Switch Bank or via i2c. You'll need some battery or big capacitor to ensure that SMS will be send.
Regards,
Bartłomiej
Hi,
By looking at the power supply page in the schematics it looks like i have to activate the "SYSTEM.OFF[2] in order to connect the capacitor to the module. Is this assumption correct?
Hello,
Please see SYSTEM.OFF on the previous page (Reset). It's for switching off the device - button OFF connects it to ground.
Regards,
Bartłomiej
Hi,
I succesfully connected my capacitor to the module, but the problem is that the module automaticly shuts down when VUSB line "dies", i can manually restart it and get power a few seconds, but that defeats the purpose. Is there any way to program it in a such a way that it stays alive when the main power line shuts down?
Regards, Willie
Hello,
I thought that your idea was to use A/D converter for reading the power source voltage as you have mentioned ADC in your first post.
Regards,
Bartłomiej
Hello,
I'm honnestly not sure what my idea is. But i have connected one ADC pin to the 5V pin to read voltage, and my tought was to somehow switch power consumption to the capacitor when the ADCs URC reads a value blow a certain threshold. I am currently reading on how the ADC API works. Would that be a working solution?
Regards, Willie
Hello,
You need to be careful and check in the hardware specification the allowed voltage range for ADC inputs - some voltage divider may be necessary. Additionally the concept board ***** some additional configuration for ADC (as there are 4 inputs multiplexed to one module's input). For Java you should be able to find some simple example projects that are using ADC in our Knowledge Base - the titles should start with "How to...".
According to the concept board documentation there is a built in charging circuit for a battery which you can connect to the BATT lines on the board. I'm not much HW oriented so I'm not sure at the moment if you can use a capacitor instead of battery and which size. The board is powered via USB cable so you'd need to find some point on the board that could be used to testing if the power is provided via this cable.
Regards,
Bartłomiej
Hello,
The ADC is pre-configured(divided by 4.17) and i could create an application that returns the value of the 5V pin(USB cable), and the idea is to call for an " Send SMS function" when that value decreases. I could also succesfully connect my capacitor to the BATT and charge it (it is a powerfull one, cap-X).
My main problem still resides, and that is : When i run a java program, any program and disconnect the USB, the bord shuts down, i can manually turn it on with the power from the capacitor. When i start the board and dont run any programs, and disconnect the USB, the board seemes to use the capacitor. Do you have any idea what can cause this or how it can be resolved?
Regards, Willie
Hello,
So the module only shuts down if there is an application running... Maybe it has something to do with current consumption (Java and network activity).
You can connect the oscilloscope to the BATT+ line to check if there is any voltage drop that could cause the shutdown.
For debugging your application and controling the module you could connect to ASC0 lines directly and reconfigure the board from FTDI to RX TX pins.
Regards,
Bartłomiej
*****,
Well, after testing alot of ***** i can say that it is completely random. Some***** it works(with application) some***** it dies instantly, even without any application running. I did some tests on the voltage in the capacitor and could not find anything strange, should i not get any URC for undervoltage anyway? if that was the case.
I do not think that it is the application causing this, it is a very simple java code. What really confueses me is that i can always turn the module on with the power from the capacitor, could it be something hardcoded in the board that has nothing to with the module?
I tried to give power directly to the 5V + GND pins, the module received power but refused to start, this leads me to belive that the module somehow monitors the VUSB and is completly reliant on it(e.g auto-shutdown when its dead, and need it for power-up).
Regards, Willie
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