How are you using GEM Pulse Counters?

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vitaliy_kh
Posts: 43
Joined: Tue Sep 28, 2010 8:46 am

How are you using GEM Pulse Counters?

Post by vitaliy_kh » Sat Feb 21, 2015 5:19 pm

Hello Everyone,

As of today I am using 3 out of 4 GEM pulse counters.
1. Natural Gas consumption monitoring;
2. Water consumption monitoring;
3. Geiger Counter for background radiation monitoring;

As you know GEM counters “as is” are very slow.
Plus if you are using more than one GEM counter and COM firmware is not latest V3.24 counters will block each other (only one counter will actually register a pulse).
My far looking ahead plan is to implement water leak detection and automatic main shutoff if leak is detected. I already have all necessary hardware in place:
- Main shutoff with actuator (this is part of very old Water Cop installation);
- Very sensitive water meter with 330 pulses per gallon rate (1 pulse is approximately 12mili liters of water consumption);
- An idea how to reliably detect water leak;
For this matter I already designed two different devices.

First device is “Pulse Spreader” for the GEM (picture is attached). It has 4 channels (one for each GEM counter). Each channel has very fast hardware counter-accumulator with input noise filtering. Output to the GEM is precisely timed. This guarantee GEM will register all pulses from all sources. The device is used for about a month and finally I have very reliable pulse counting results.

Second device is stand alone pulse counter. It has 16 very fast counters and simply sends packets to the DashBox. Ben promised to add support for the this toy to the DashBox. As of yesterday the device is sending formatted packets to the Brultech server and Ben said so far everything looks good. So now it is Ben’s turn to integrate this toy with DashBox.

I am an experienced HW designer. Both these devices are implemented with programmable logic and done in VHDL. “Pulse Spreader” fits nicely into 256 cells CPLD. I am using CoolRunnerII CPLD development board from Digilent Inc. Pulse Counter box is more complicated. It has embedded MicroBlaze processor and requires mid size FPGA. Since MicroBlaze CPU is Xilinx proprietary FPGA must be from Xilinx. I am using cheap development board with XC6SLX9 Xilinx device.

Please let me know if anyone is interested in these toys. Certainly I can/will share all design files but support will be very minimal.

- Vitaliy
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