adc_temperature: Calculate "PT100 INA826" values from formula

Calculate the "PT100 INA826" values instead of using a voltage table.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 7 insertions, 13 deletions

diff --git a/klippy/extras/adc_temperature.py b/klippy/extras/adc_temperature.py
index 6e02118a..64f58cd1 100644
--- a/klippy/extras/adc_temperature.py
+++ b/klippy/extras/adc_temperature.py
@@ -261,19 +261,6 @@ AD8497 = [
     (1360, 6.671), (1380, 6.754)
 ]
 
-PT100 = [
-    (0, 0.00), (1, 1.11), (10, 1.15), (20, 1.20), (30, 1.24), (40, 1.28),
-    (50, 1.32), (60, 1.36), (70, 1.40), (80, 1.44), (90, 1.48), (100, 1.52),
-    (110, 1.56), (120, 1.61), (130, 1.65), (140, 1.68), (150, 1.72),
-    (160, 1.76), (170, 1.80), (180, 1.84), (190, 1.88), (200, 1.92),
-    (210, 1.96), (220, 2.00), (230, 2.04), (240, 2.07), (250, 2.11),
-    (260, 2.15), (270, 2.18), (280, 2.22), (290, 2.26), (300, 2.29),
-    (310, 2.33), (320, 2.37), (330, 2.41), (340, 2.44), (350, 2.48),
-    (360, 2.51), (370, 2.55), (380, 2.58), (390, 2.62), (400, 2.66),
-    (500, 3.00), (600, 3.33), (700, 3.63), (800, 3.93), (900, 4.21),
-    (1000, 4.48), (1100, 4.73)
-]
-
 def calc_pt1000():
     # Calc PT1000 temperature/resistance pairs using formula
     A, B = (3.9083e-3, -5.775e-7)
@@ -281,6 +268,13 @@ def calc_pt1000():
 
 PT1000 = calc_pt1000()
 
+def calc_ina826_pt100():
+    PT100 = [(t, .1 * r) for t, r in PT1000]
+    # Standard circuit is 4400ohm pullup with 10x gain to 5V
+    return [(t, 10. * 5. * r / (4400. + r)) for t, r in PT100]
+
+PT100 = calc_ina826_pt100()
+
 def load_config(config):
     # Register default sensors
     pheaters = config.get_printer().load_object(config, "heaters")