signal.adc.rctime.spin

{
    --------------------------------------------
    Filename: signal.adc.rctime.spin
    Author: Jesse Burt
    Description: Measure capacitor charge time through resistor
    Started 2007
    Updated Nov 7, 2022
    See end of file for terms of use.
    --------------------------------------------

    NOTE: This is based on RCTIME.spin, originally by
        Beau Schwabe
}
CON

    BACKGROUND = 1

OBJ

    time : "time"

VAR

    long _cog
    long _rcstack[16]
    long _rctemp
    long _mode

PUB null{}
' This is not a top-level object

PUB start(pin, state, ptr_rcvalue): status
' Start RC-time calculator in another core/cog
' Return: cog id, or 0 if none available
    stop{}
    status := _cog := (cognew(calc_rctime(pin, state, ptr_rcvalue), @_rcstack) + 1)
    _mode := BACKGROUND

PUB stop{}
' Stop RCTime
    if (_cog)
        cogstop(_cog)
    longfill(@_cog, 0, 19)

PUB calc_rctime(pin, state, ptr_rcvalue)
' Calculate RC-time
    repeat
        outa[pin] := state                      ' charge cap
        dira[pin] := 1
        time.msleep(1)                          ' pause for 1mS to charge cap
        dira[pin] := 0
        _rctemp := cnt                          ' get timestamp
        waitpeq(1 - state, |< pin, 0)           ' wait until pin changes state
        _rctemp := cnt - _rctemp                ' get elapsed time
        _rctemp := _rctemp - 1600               ' adjust for overhead
        _rctemp := _rctemp >> 4 { /16 }         ' scale result
        long[ptr_rcvalue] := _rctemp            ' copy result
    while (_mode)                               ' keep running if mode is different than FOREGROUND

DAT
{
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
associated documentation files (the "Software"), to deal in the Software without restriction,
including without limitation the rights to use, copy, modify, merge, publish, distribute,
sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or
substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
}