Pulse Count Module

NETMF & Gadgeteer
1

I am trying to read a flowmeter and have it connected to a Pulse Count Module (PULSE-GM-465) in turn connected to a Raptor. I have a couple of questions

1 - My range of readings will vary from very slow (0.5Hz up to around 120Hz) and setting a timer to look at the pulse count from the module will not produce the output I want . For this reason I have it wired to the IN terminal and I am exposing an Interrupt which allows me to look at the interval between pulses and more rapidly respond to changes in speed.

This works fine but looking further ahead is there any need to use the module at all, or is it literally exposing the Interrupt capable Pin3 on the underlying socket ?

2 - I read various references about some mainboards being 5V tolerant on the Interrupt pins but I can’t find a definitive answer to this. Is the IN terminal on the Pulse Count module 5V tolerant ? and same question for a direct connection to Pin3 on the socket on a Raptor.

3 - Using the InterruptInput at the gadgeteer ‘level’ unfortunately does not include the timestamp from the underlying native interrupt handler. Is this an oversight in the gadgeteer code or is there a specific reason ?

Thanks in advance

Steve

2

@ sh - You should be able to connect the interrupt pin directly to pin 3 and bypass the module. All the module does is provide a pull up resistor. The FEZ Raptor is not 5 V tolerant on any pin. I’m not sure why the Gadgeteer core doesn’t expose the timestamp.

3

@ John - Thanks for your response, I posted a ‘fix’ to the issues of no timestamp being exposed in the event. Its a bit of a ‘hack’ but for my scenario it has work well

https://www.ghielectronics.com/community/codeshare/entry/1058