Edit functions for int/float type, added counts-to-volts

diff --git a/work-eqs.el b/work-eqs.el
index a66104411bad114f60ea95df7d11ffa6ae55efef..88b12b9920d6ab0621cfe20968cc3309fb33804e 100644 (file)
--- a/work-eqs.el
+++ b/work-eqs.el
@@ -83,9 +83,14 @@ Applies `c-to-k' to `f-to-c'."
 (defun max-counts (resolution)
   "Calculate the max count for a PLC analog, given card's bit-resolution.
 Formula is 1 - 2^(resolution)"
-  (- (expt 2 resolution) 1.0))
+  (- (expt 2 resolution) 1))
 
 (defun volts-to-counts (vin vmax resolution)
   "Convert a voltage signal to a PLC count.
 Calculates a ratio of vin/vmax, then scales by `max-counts'."
-  (* (/ vin vmax) (max-counts resolution)))
+  (* (/ (float vin) (float vmax)) (float (max-counts resolution))))
+
+(defun counts-to-volts (cin vmax resolution)
+  "Convert a PLC count to a voltage.
+Calculates a ratio of cin/`max-counts', then multiplies by vmax."
+  (* (/ cin (float (max-counts resolution))) vmax))