[time-nuts] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE

Tom Van Baak (Lab) tvb at leapsecond.com
Tue Feb 19 23:32:30 EST 2013

On Feb 19, 2013, at 5:38 PM, Hal Murray <hmurray at megapathdsl.net> wrote:

> paulc at snet.net said:
>> The actual electrodes instrumentation amp is pretty much working fine  so no
>> worries there.
>> My first tthought was a frequency to voltage IC like the LM2907 or the 2917
>> but I get the impresiion from the data sheets that these chips will not work
>> at these very low 1 Hz applications,
> If you have clean pulses, connect them up to the PPS input on a PC serial 
> port.  The rest is software.

Windows PC-based time stamping counter: http://leapsecond.com/tools/pctsc.c
But I'd opto-isolate a PC serial port before I put it too close to my heart.

Sent from my iPad/mini

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