;;; -*- lexical-binding: t -*-
;;
;; this file:
;;   https://dataswamp.org/~incal/terror-3/ev3-ir-prox-alert.el

(require 'ev3-ir)
(require 'ev3-motor-stop)
(require 'ev3-motor-straight)

(defun ir-prox-too-close-p ()
  (let ((stop-dist 90) ; 100 is 70 cm
        (prox (ir-get-prox)) )
    (< prox stop-dist) ))

(defun ir-prox-stop (&optional time)
  (interactive)
  (or time (setq time 50))
  (when (ir-prox-too-close-p)
    (when (moving-forward-p)
      (ev3-stop) )
    (dotimes (_ 3)
      (when (ir-prox-too-close-p)
        (ev3-reverse-inc)
        (sleep-for 0 (* 75 time)) ))
    (ev3-stop) ))

(provide 'ev3-ir-prox-alert)