From cc8894f703a90f4acb4dd1988cfdba6fa5a9e1b6 Mon Sep 17 00:00:00 2001
From: Moritz Ruffer <m.ruffer@fasttube.de>
Date: Fri, 4 Apr 2025 22:10:22 +0200
Subject: [PATCH] feat: add code for lookup table generation

---
 AMS_Master_Code/temp_gen_adbms.py | 89 +++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 AMS_Master_Code/temp_gen_adbms.py

diff --git a/AMS_Master_Code/temp_gen_adbms.py b/AMS_Master_Code/temp_gen_adbms.py
new file mode 100644
index 0000000..dbf5cf9
--- /dev/null
+++ b/AMS_Master_Code/temp_gen_adbms.py
@@ -0,0 +1,89 @@
+import numpy as np
+import matplotlib.pyplot as plt  # Import matplotlib for plotting
+
+# Constants
+NTC_A1 = 0.003354016
+NTC_B1 = 0.000300131
+NTC_C1 = 5.08516E-06
+NTC_D1 = 2.18765E-07
+
+LOW_TEMP = 0
+HIGH_TEMP = 70
+N = 16  # Number of bits
+VREF = 3.0
+RESOLUTION = 0.01 # temp is in 0.01°C
+TEMP_CONV = 1/RESOLUTION
+CELSIUS_TO_KELVIN = 273.15
+
+
+def calc_temp_c(adc_voltage):
+    log_ohms = np.log(1 / ((VREF / adc_voltage) - 1))
+    temperature = 1 / (
+        NTC_A1 +
+        NTC_B1 * log_ohms +
+        NTC_C1 * log_ohms**2 +
+        NTC_D1 * log_ohms**3
+    ) - CELSIUS_TO_KELVIN
+    return temperature
+
+def calc_voltage(adc_code):
+    return adc_code * 150e-6 + 1.5  # Convert ADC ADBMS code to voltage
+
+def temp_table(adc_codes):
+    temp = []
+    for adc_code in adc_codes:  # Signed 16-bit ADC range
+        adc_voltage = calc_voltage(adc_code)
+        try:
+            temperature = calc_temp_c(adc_voltage)
+        except (ValueError, ZeroDivisionError):
+            temperature = None # Handle invalid calculations gracefully
+        temp.append(temperature)
+    return np.array(temp)
+
+def make_c_code(temp_values, low_t_adc, high_t_adc):
+    # generate C code of an array and put into code.c file
+    with open("tempTable.h", "w") as f:
+        f.write("#include <stdint.h>\nconst uint16_t ADC2TEMP[] = {\n")
+        for temp in temp_values:
+            f.write(f" {(int)(temp*TEMP_CONV)}")
+            if temp != temp_values[-1]:
+                f.write(",")
+        f.write("};")
+
+    with open("tempCalc.c", "w") as f:
+        f.write("""#include "tempTable.h"
+
+    static inline uint16_t ntc_mv_to_celsius(int16_t adc) {
+        // Out of bounds checking --> done by OV/UV setting of the BMS?
+        if (adc < """ + str(int(low_t_adc)) + """ || adc > """ + str(int(high_t_adc)) + """) {
+            return -1;
+        }
+        return ADC2TEMP[adc + """ + str(-int(low_t_adc)) + """];
+    }
+    """)
+
+
+if __name__ == "__main__":
+    adc_codes = np.linspace(-2**(N - 1), 2**(N - 1) - 1, 2**N)
+    temp_values = temp_table(adc_codes)
+
+    bool_vec = (temp_values >= LOW_TEMP) & (temp_values <= HIGH_TEMP)
+
+    low_t_adc = adc_codes[bool_vec][0]
+    high_t_adc = adc_codes[bool_vec][-1]
+    print(f"ADC code for {LOW_TEMP}°C: {low_t_adc}")
+    print(f"ADC code for {HIGH_TEMP}°C: {high_t_adc}")
+
+    plt.figure(figsize=(10, 6))
+    plt.plot(adc_codes[bool_vec], temp_values[bool_vec], "b", label="0°C to 70°C")
+    # plt.plot(adc_codes, temp_values, "r")
+    # plt.xlim([-10000, 10000])
+    plt.title("ADC Code to Temperature Conversion")
+    plt.xlabel("ADC Code")
+    plt.ylabel("Temperature (°C)")
+    plt.grid(True)
+    plt.legend()
+    plt.show()
+
+    make_c_code(temp_values[bool_vec], low_t_adc, high_t_adc)
+