From 177dbcde6a369977ba73264e9a93d8ad97a91f1a Mon Sep 17 00:00:00 2001
From: Bernd Porr <mail@berndporr.me.uk>
Date: Wed, 25 Aug 2021 14:11:39 +0100
Subject: [PATCH] Tested the 1kHz sampling rate and seems to be OK

---
 README.md                       |  4 +-
 README_py.rst                   |  4 +-
 examples/realtime_1kHz_scope.py | 87 +++++++++++++++++++++++++++++++++
 3 files changed, 91 insertions(+), 4 deletions(-)
 create mode 100755 examples/realtime_1kHz_scope.py

diff --git a/README.md b/README.md
index fb553a6b..b9599552 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 
 PyFirmata2 turns your Arduino into a data acquisition card controlled by Python.
 
-Up to 100Hz precise sampling at the analogue ports for digital filtering.
+Up to 1kHz precise sampling at the analogue ports for digital filtering.
 
 Just upload the default firmata sketch into your Arduino and you are all set.
 
@@ -89,7 +89,7 @@ check for the latest addition: `ls -l -t /dev/*`.
 ### Starting sampling at a given sampling interval
 
 In order to sample analogue data you need to specify a
-sampling interval in ms. The smallest interval is 10ms:
+sampling interval in ms. The smallest interval is 1ms:
 ```
     board.samplingOn(samplinginterval in ms)
 ```
diff --git a/README_py.rst b/README_py.rst
index 0af18d15..53dc6227 100644
--- a/README_py.rst
+++ b/README_py.rst
@@ -4,7 +4,7 @@ pyFirmata2
 
 PyFirmata2 turns your Arduino into a data acquisition card controlled by Python.
 
-Up to 100Hz precise sampling at the analogue ports for digital filtering.
+Up to 1kHz precise sampling at the analogue ports for digital filtering.
 
 Just upload the default firmata sketch into your Arduino and you are all set.
 
@@ -90,7 +90,7 @@ Starting sampling at a given sampling interval
 ----------------------------------------------
 
 In order to sample analogue data you need to specify a
-sampling interval in ms. The smallest interval is 10ms::
+sampling interval in ms. The smallest interval is 1ms::
 
     board.samplingOn(samplinginterval in ms)
 
diff --git a/examples/realtime_1kHz_scope.py b/examples/realtime_1kHz_scope.py
new file mode 100755
index 00000000..0645cab7
--- /dev/null
+++ b/examples/realtime_1kHz_scope.py
@@ -0,0 +1,87 @@
+#!/usr/bin/python3
+"""
+Plots channels zero and one in two different windows. Requires pyqtgraph.
+
+Copyright (c) 2018-2020, Bernd Porr <mail@berndporr.me.uk>
+see LICENSE file.
+
+"""
+
+import sys
+
+import pyqtgraph as pg
+from pyqtgraph.Qt import QtCore, QtGui
+
+import numpy as np
+
+from pyfirmata2 import Arduino
+PORT = Arduino.AUTODETECT
+
+# create a global QT application object
+app = QtGui.QApplication(sys.argv)
+
+# signals to all threads in endless loops that we'd like to run these
+running = True
+
+class QtPanningPlot:
+
+    def __init__(self,title):
+        self.win = pg.GraphicsLayoutWidget()
+        self.win.setWindowTitle(title)
+        self.plt = self.win.addPlot()
+        self.plt.setYRange(-1,1)
+        self.plt.setXRange(0,500)
+        self.curve = self.plt.plot()
+        self.data = []
+        # any additional initalisation code goes here (filters etc)
+        self.timer = QtCore.QTimer()
+        self.timer.timeout.connect(self.update)
+        self.timer.start(100)
+        self.layout = QtGui.QGridLayout()
+        self.win.setLayout(self.layout)
+        self.win.show()
+        
+    def update(self):
+        self.data=self.data[-500:]
+        if self.data:
+            self.curve.setData(np.hstack(self.data))
+
+    def addData(self,d):
+        self.data.append(d)
+
+# Let's create two instances of plot windows
+qtPanningPlot1 = QtPanningPlot("Arduino 1st channel")
+
+# sampling rate: 100Hz
+samplingRate = 1000
+
+# called for every new sample at channel 0 which has arrived from the Arduino
+# "data" contains the new sample
+def callBack(data):
+    # filter your channel 0 samples here:
+    # data = self.filter_of_channel0.dofilter(data)
+    # send the sample to the plotwindow
+    qtPanningPlot1.addData(data)
+
+# Get the Ardunio board.
+board = Arduino(PORT)
+
+# Set the sampling rate in the Arduino
+board.samplingOn(1000 / samplingRate)
+
+# Register the callback which adds the data to the animated plot
+# The function "callback" (see above) is called when data has
+# arrived on channel 0.
+board.analog[0].register_callback(callBack)
+
+# Enable the callback
+board.analog[0].enable_reporting()
+board.analog[1].enable_reporting()
+
+# showing all the windows
+app.exec_()
+
+# needs to be called to close the serial port
+board.exit()
+
+print("Finished")