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ADC.spin
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ADC.spin
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{{
*****************************************
* generic ADC driver v1.0 *
* Author: Beau Schwabe *
* Copyright (c) 2007 Parallax *
* See end of file for terms of use. *
*****************************************
}}
CON
SDF = 6 'sigma-delta feedback
SDI = 7 'sigma-delta input
PUB SigmaDelta (sample)
cognew(@asm_entry, sample) 'launch assembly program in a COG
DAT
org
asm_entry mov dira,#1<<SDF 'make SDF pin an output
movs ctra,#SDI 'POS W/FEEDBACK mode for CTRA
movd ctra,#SDF
movi ctra,#%01001_000
mov frqa,#1
mov asm_c,cnt 'prepare for WAITCNT loop
add asm_c,asm_cycles
:loop waitcnt asm_c,asm_cycles 'wait for next CNT value
'(timing is determinant after WAITCNT)
mov asm_new,phsa 'capture PHSA
mov asm_sample,asm_new 'compute sample from 'new' - 'old'
sub asm_sample,asm_old
mov asm_old,asm_new
wrlong asm_sample,par 'write sample back to Spin variable "sample"
'(WRLONG introduces timing indeterminancy here..)
'(..since it must sync to the HUB)
jmp #:loop 'wait for next sample
asm_cycles long $FFFF '(use $FFFF for 16-bit, $FFF for 12-bit, or $FF for 8-bit)
asm_c res 1 'uninitialized variables follow emitted data
asm_cnt res 1
asm_new res 1
asm_old res 1
asm_sample res 1
asm_temp res 1
DAT
{{
┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ TERMS OF USE: MIT License │
├──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│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. │
└──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
}}