\ A small analog input example for Calliope

\ Tasks:
$40007000 constant adc_start
$40007004 constant adc_stop

\ Events:
$40007100 constant adc_end

\ Registers:
$40007400 constant adc_busy
$40007500 constant adc_enable
$40007504 constant adc_config
$40007508 constant adc_result

: init-analog ( -- )
  1 adc_enable !
;

: analog ( channel -- result )
  \ 1 adc_stop !
  $200 swap lshift 2 or adc_config !  \ Select input channel and 10 bits resolution with internal 1.2V bandgap reference
  1 adc_start !
  begin 1 adc_busy bit@ not until
  adc_result @
;

: analog-demo ( -- ) \ Reads all three banana jack ports
  init-analog
  begin
    2 analog u. 1 analog u. cr
  key? until
;