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#!/usr/bin/env python3
import time
import statistics
import sqlite3
from datetime import datetime
from pyBusPirateLite import BitBang
if __name__ == '__main__':
import argparse
parser = argparse.ArgumentParser()
parser.add_argument('-s', '--steps', type=int, nargs='?', default=400, help='Steps to run through')
parser.add_argument('-k', '--skip', type=int, nargs='?', default=2, help='Steps skip between measurements for shorter runtime')
parser.add_argument('-d', '--database', default='spectra.sqlite3', help='sqlite3 database file to store results in')
parser.add_argument('-w', '--wait', type=float, default=2.0, help='time to wait between samples in seconds')
parser.add_argument('-o', '--oversample', type=int, default=32, help='oversampling ratio')
parser.add_argument('-g', '--gain', type=float, default=None, help='Transimpedance gain of amplifier in MOhm')
parser.add_argument('-c', '--comment', help='run comment')
parser.add_argument('-p', '--port', default='/dev/serial/by-id/usb-FTDI_FT232R_USB_UART_AD01W1RF-if00-port0', help='Serial port device of the control buspirate')
parser.add_argument('run_name', nargs='?', default='auto')
parser.add_argument('color', help='Captured color channel')
args = parser.parse_args()
db = sqlite3.connect(args.database)
db.execute("""
CREATE TABLE IF NOT EXISTS runs (
capture_id INTEGER PRIMARY KEY,
name TEXT,
comment TEXT,
color TEXT, -- Captured color channel
gain REAL, -- Preamplifier transimpedance in Ohms
timestamp REAL -- unix timestamp in fractional seconds
)""")
db.execute("""
CREATE TABLE IF NOT EXISTS measurements (
measurement_id INTEGER PRIMARY KEY,
capture_id INTEGER,
led_on INTEGER,
step INTEGER,
voltage REAL, -- volts
voltage_stdev REAL, -- volts
timestamp REAL, -- unix timestamp in fractional seconds
FOREIGN KEY (capture_id) REFERENCES runs)""")
class BPState:
def __init__(self, port):
self.bp = BitBang(port)
self._led = 0
self._stepper_dir = 'down'
self.reinit()
def reinit(self):
self.bp.enter_bb()
self.led(self._led)
self.stepper_direction(self._stepper_dir)
self.bp.cs = 0
def led(self, st):
self._led = st
self.bp.mosi = st
def stepper_direction(self, direction):
self._stepper_dir = direction
self.bp.aux = 0 if direction == 'down' else 1
def step(self):
self.bp.cs = 1
time.sleep(0.005)
self.bp.cs = 0
time.sleep(0.005)
def adc(self, oversampling):
self.reinit()
return [ self.bp.adc_value for _ in range(oversampling) ]
bp = BPState(args.port)
with db:
cur = db.cursor()
cur.execute('INSERT INTO runs(name, comment, color, gain, timestamp) VALUES (?, ?, ?, ?, ?)',
(args.run_name, args.comment, args.color, args.gain*1e6, time.time()))
capture_id = cur.lastrowid
print('Starting capture {} "{}" at {:%y-%m-%d %H:%M:%S:%f}'.format(capture_id, args.run_name, datetime.now()))
print('[measurement id] " " [step number] " " [reading (V)]')
bp.stepper_direction('down')
for _ in range(10):
bp.step()
bp.stepper_direction('up')
for step in range(0, args.steps+args.skip, args.skip): # Run one skip past end to capture both interval boundaries
for led_val in [1]: # This can be used for self-calibration.
try:
bp.led(led_val)
time.sleep(args.wait)
readings = bp.adc(args.oversample)
mean, stdev = statistics.mean(readings), statistics.stdev(readings)
with db:
cur = db.cursor()
cur.execute('''
INSERT INTO measurements (
capture_id, led_on, step, voltage, voltage_stdev, timestamp
) VALUES (?, ?, ?, ?, ?, ?)''',
(capture_id, led_val, step, mean, stdev, time.time()))
print('{:08d} {:03} {}: {:5.4f} stdev {:5.4f}'.format(
cur.lastrowid, step, led_val, mean, stdev))
except KeyboardInterrupt:
raise
except TypeError as e:
print('Buspirate hiccup, ignoring:', e)
for _ in range(args.skip):
bp.step()
bp.stepper_direction('down')
for _ in range(args.steps+args.skip):
bp.step()
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