Multiple Meta Motion R

lmoro

Hello everyone!

I have just started working with new Meta Motion R. We are trying to build an application that records from two Meta Motion R contemporary.

Does anyone has used multiple devices with Pymetawear?Is it possible?Is there some sample code  that do so?

What do you use for multiple devices applications? 

Thank you

Lucia

Eric

The pymetawear project is not maintained by Mbientlab; it is a community provided API by user @hbldh.  I do not know how often he checks this forum so you may be better asking him directly by filing a question on the project's GitHub page.

The README and project provide examples on connecting to one device.  Have you tried writing a script that replicates the MetaWearClient example code twice in a single Python script?

hbldh

It isn't more complicated than this:

import time
from pymetawear.client import MetaWearClient

address_1 = 'DD:3A:7D:4D:56:F0'
address_2 = 'FF:...'
client_1 = MetaWearClient(str(address_1), debug=True)
client_2 = MetaWearClient(str(address_2), debug=True)

print("Blinking 10 times with green LED on client 1...")
pattern = client_1.led.load_preset_pattern('blink', repeat_count=10)
client_1.led.write_pattern(pattern, 'g')
client_1.led.play()

print("Blinking 10 times with red LED on client 2...")
pattern = client_2.led.load_preset_pattern('blink', repeat_count=10)
client_2.led.write_pattern(pattern, 'r')
client_2.led.play()

time.sleep(5.0)

client_1.disconnect()
client_2.disconnect()

Just create a new client for each board and address them separately.

hbldh

Added the code above as an example in the new 0.7.0 release of PyMetaWear today: https://github.com/hbldh/pymetawear/blob/master/examples/two_clients.py

lmoro

Thank you!

That is more or less what I was doing but I'm getting two mayors problems:

•  I have lots of pygatt.exceptions.NotConnectedError after calling

   MetaWearClient(str(address_1), debug=False)

    if i set debug to true it gets stuck at INFO Connecting GATTTool...
• When the connection happens the first device that connects send far more data than the second one. This is the code that I am using:

class HandleAccelerometer(object):

    def __init__(self, mac_address, data_rate=50.0, data_range=8):
        self._mac_address = mac_address
        self._data_rate = data_rate
        self._data_range = data_range
        self._nrec = 0
        # self.connect()

    def callback(self, data):
        print('Received from: ', self._mac_address, self._nrec)
        # print("Epoch time: [{0}] - X: {1}, Y: {2}, Z: {3}".format(data[0], *data[1]))
        self._nrec += 1

    def connect(self, time_out=25, tries=105):
        for i in range(tries):
            try:
                print('Trying to connect: %s, #%d' % (self._mac_address, i))
                # must be saved as self
                self.c = MetaWearClient(self._mac_address, timeout=time_out, debug=True)
                self.c.accelerometer.set_settings(data_rate=self._data_rate,
                                                  data_range=self._data_range)
            except Exception as e:
                print('Exception', type(e), self._mac_address)
            else:
                print('Connected')
                self.connected = True
                # self.c.accelerometer.notifications(self.callback)
                break

    def associate_callback(self):
        self.c.accelerometer.notifications(self.callback)

    def run_all(self):
        self.connect()


def foo(mac_address):
    ha = HandleAccelerometer(mac_address)
    ha.connect()
    time.sleep(150)
    ha.associate_callback()
    while True:
        pass

mac_address = ['EE:08:AC:39:24:F7', 'E1:DA:57:F1:3B:27']
from multiprocessing import Process
all_p = []
for mc in mac_address:
    p = Process(target=foo, args=(mc, ))
    p.start()


time.sleep(300)
for i in all_p:
    p.join()


has = [HandleAccelerometer(i) for i in mac_address]

for i in has:
    print('Starting ', i._mac_address)
    _thread.start_new_thread(i.run_all, tuple())

Any advice?

Lucia