initial commit...

emi_scanner.py

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+import time
+import os
+import sys
+import serial
+import csv
+from tsapython import tinySA
+import datetime
+import numpy as np
+import matplotlib.pyplot as plt
+
+ser = serial.Serial("/dev/ttyACM2", 115200)
+
+max_x = 250
+max_y = 200
+max_z = 150
+
+min_z = 50
+z_search = 100
+
+
+prboffs_x = 40
+prboffs_y = 40
+prboffs_z = 10
+
+
+feedrate = 5000
+
+now = datetime.datetime.now()
+
+
+def convert_data_to_arrays(start, stop, pts, data):
+    # using the start and stop frequencies, and the number of points,
+
+    freq_arr = np.linspace(
+        start, stop, pts
+    )  # note that the decimals might go out to many places.
+    # you can truncate this because it’s only used
+    # for plotting in this example
+
+    # As of the Jan. 2024 build in some data returned with SWEEP or SCAN calls there is error data.
+    # https://groups.io/g/tinysa/topic/tinasa_ultra_sweep_command/104194367
+    # this shows up as "-:.000000e+01".
+    # TEMP fix - replace the colon character with a -10. This puts the 'filled in' points around the noise floor.
+    # more advanced filtering should be applied for actual analysis.
+    data1 = bytearray(data.replace(b"-:.0", b"-10.0"))
+
+    # get both values in each row returned (for reference)
+    # data_arr = [list(map(float, line.split())) for line in data.decode('utf-8').split('\n') if line.strip()]
+
+    # get first value in each returned row
+    data_arr = [
+        float(line.split()[0])
+        for line in data1.decode("utf-8").split("\n")
+        if line.strip()
+    ]
+
+    return freq_arr, data_arr
+
+
+def writeCSV(freq_array, data, csv_filename):
+    try:
+        with open(csv_filename, "w", newline="") as csvfile:
+            writer = csv.writer(csvfile, delimiter=";")
+            writer.writerow(
+                f'# Nearfield Scan {now.strftime("%Y-%m-%d %H:%M")}, {desc}'
+            )
+            row = []
+            row.append("# ;;")
+            for elem in freq_array:
+                row.append(str(elem))
+            writer.writerow(row)
+
+            for key in data:
+                row = []
+                row.append(key, data[key])
+                writer.writerow(row)
+    except IOError:
+        print("I/O error")
+    return
+
+
+def initXYZ():
+    ser.write(str.encode("M17 \r\n"))
+    ser.write(str.encode("M84 X Y Z S12000\r\n"))
+    ser.write(str.encode("M84 E\r\n"))
+    ser.write(str.encode("G28\r\n"))
+
+    # set to absolute movement
+    ser.write(str.encode("G90\r\n"))
+    time.sleep(20)
+
+
+def main():
+    import argparse
+    import configparser
+
+    parser = argparse.ArgumentParser(
+        prog="3D NearField Scanner",
+        description="Uses a 3D Printer and a Tiny SA for measureing the near field of a PCB",
+        epilog="=^.^=",
+    )
+
+    parser.add_argument("--fstart", type=float, default=1e6)
+
+    parser.add_argument("--fstop", type=float, default=800e6)
+
+    parser.add_argument("--pts", type=int, default=450)
+
+    parser.add_argument(
+        "--rbw",
+        help="RBW in kHz",
+        default=auto,
+        choices=[200, 1, 3, 10, 30, 100, 300, 600, 850],
+    )
+
+    parser.add_argument("--xstart", type=int, default=0, help="x start in mm")
+
+    parser.add_argument("--xend", type=int, default=250, help="x end in mm")
+
+    parser.add_argument("--ystart", type=int, default=0, help="y start in mm")
+
+    parser.add_argument("--yend", type=int, default=200, help="y end in mm")
+    parser.add_argument("--xstep", type=int, default=10, help="x step in mm")
+
+    parser.add_argument("--ystep", type=int, default=10, help="y step in mm")
+
+    parser.add_argument("--desc", type=str, default="", help="EUT Description")
+
+    args = parser.parse_args()
+
+    # scan surface
+    ser.write(str.encode(f"G1 Z{min_z}\r\n"))
+    input("Attach Probe and press Enter to continue...")
+    print("Starting Measurement")
+
+    # create a new tinySA object
+    tsa = tinySA()
+
+    # set the return message preferences
+    tsa.set_verbose(True)  # detailed messages
+    tsa.set_error_byte_return(True)  # get explicit b'ERROR' if error thrown
+
+    # attempt to autoconnect
+    found_bool, connected_bool = tsa.autoconnect()
+
+    # if port closed, then return error message
+    if connected_bool == False:
+        print("ERROR: could not connect to port")
+    else:  # if port found and connected, then complete task(s) and disconnect
+
+        if args.rbw == "auto":
+            tsa.set_rbw_auto()
+        else:
+            tsa.rbw(int(args.rbw))
+
+        datadict = {}
+
+        for y in range(args.ystart, args.yend, args.ystep):
+            if y >= max_y - args.ystep:
+                break
+            else:
+                ser.write(str.encode(f"G1 X{args.xstart} Y{y} F{feedrate}\r\n"))
+                time.sleep(2)
+
+            for x in range(args.xstart, args.xend, args.xstep):
+                if x >= max_x - args.xstep:
+                    break
+                else:
+
+                    ser.write(str.encode(f"G1 X{x} Z{z_search} F{feedrate}\r\n"))
+                    time.sleep(1)
+                    ser.write(str.encode(f"G1 Z{min_z} F{feedrate}\r\n"))
+                    ser.write(str.encode("M18 \r\n"))  # disable steppers
+                    tsa.resume()  # scan
+                    data_bytes = tsa.scan(args.fstart, args.fstop, args.pts, 2)
+                    tsa.wait()
+                    ser.write(str.encode("M17 X Y Z\r\n"))  # enable steppers
+                    ser.write(str.encode(f"G1 Z{z_search} F{feedrate}\r\n"))
+
+                    freq_arr, data_arr = convert_data_to_arrays(
+                        start, stop, pts, data_bytes
+                    )
+                    datadict[f"{str(x)};{str(y)}"] = data_arr
+                    time.sleep(1)
+        writeCSV(freq_arr, datadict, "test.csv")
+        tsa.resume()  # resume so screen isn't still frozen
+        tsa.disconnect()
+
+
+if __name__ == "__main__":
+    sys.exit(main())