some bluetooth and odrive updates

master
Drew Bednar 3 years ago
parent f6262ba212
commit 259ea914ff

@ -0,0 +1,93 @@
# Helpers for generating BLE advertising payloads.
from micropython import const
import struct
import bluetooth
# Advertising payloads are repeated packets of the following form:
# 1 byte data length (N + 1)
# 1 byte type (see constants below)
# N bytes type-specific data
_ADV_TYPE_FLAGS = const(0x01)
_ADV_TYPE_NAME = const(0x09)
_ADV_TYPE_UUID16_COMPLETE = const(0x3)
_ADV_TYPE_UUID32_COMPLETE = const(0x5)
_ADV_TYPE_UUID128_COMPLETE = const(0x7)
_ADV_TYPE_UUID16_MORE = const(0x2)
_ADV_TYPE_UUID32_MORE = const(0x4)
_ADV_TYPE_UUID128_MORE = const(0x6)
_ADV_TYPE_APPEARANCE = const(0x19)
# Generate a payload to be passed to gap_advertise(adv_data=...).
def advertising_payload(limited_disc=False, br_edr=False, name=None, services=None, appearance=0):
payload = bytearray()
def _append(adv_type, value):
nonlocal payload
payload += struct.pack("BB", len(value) + 1, adv_type) + value
_append(
_ADV_TYPE_FLAGS,
struct.pack("B", (0x01 if limited_disc else 0x02) + (0x18 if br_edr else 0x04)),
)
if name:
_append(_ADV_TYPE_NAME, name)
if services:
for uuid in services:
b = bytes(uuid)
if len(b) == 2:
_append(_ADV_TYPE_UUID16_COMPLETE, b)
elif len(b) == 4:
_append(_ADV_TYPE_UUID32_COMPLETE, b)
elif len(b) == 16:
_append(_ADV_TYPE_UUID128_COMPLETE, b)
# See org.bluetooth.characteristic.gap.appearance.xml
if appearance:
_append(_ADV_TYPE_APPEARANCE, struct.pack("<h", appearance))
return payload
def decode_field(payload, adv_type):
i = 0
result = []
while i + 1 < len(payload):
if payload[i + 1] == adv_type:
result.append(payload[i + 2 : i + payload[i] + 1])
i += 1 + payload[i]
return result
def decode_name(payload):
n = decode_field(payload, _ADV_TYPE_NAME)
return str(n[0], "utf-8") if n else ""
def decode_services(payload):
services = []
for u in decode_field(payload, _ADV_TYPE_UUID16_COMPLETE):
services.append(bluetooth.UUID(struct.unpack("<h", u)[0]))
for u in decode_field(payload, _ADV_TYPE_UUID32_COMPLETE):
services.append(bluetooth.UUID(struct.unpack("<d", u)[0]))
for u in decode_field(payload, _ADV_TYPE_UUID128_COMPLETE):
services.append(bluetooth.UUID(u))
return services
def demo():
payload = advertising_payload(
name="micropython esp32",
services=[bluetooth.UUID(0x181A), bluetooth.UUID("6E400001-B5A3-F393-E0A9-E50E24DCCA9E")],
)
print(payload)
print(decode_name(payload))
print(decode_services(payload))
if __name__ == "__main__":
demo()

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# This module demonstrates uses the Nordic UART Service (NUS) to interpret gamepad
import bluetooth
from ble_advertising import advertising_payload
from micropython import const
_IRQ_CENTRAL_CONNECT = const(1)
_IRQ_CENTRAL_DISCONNECT = const(2)
_IRQ_GATTS_WRITE = const(3)
_FLAG_WRITE = const(0x0008)
_FLAG_NOTIFY = const(0x0010)
# The 128-bit vendor-specific service UUID is 6E400001-B5A3-F393-E0A9-E50E24DCCA9E (16-bit offset: 0x0001).
_UART_UUID = bluetooth.UUID("6E400001-B5A3-F393-E0A9-E50E24DCCA9E")
# Defines the UART_TX characteristic
# Notify
_UART_TX = (
bluetooth.UUID("6E400003-B5A3-F393-E0A9-E50E24DCCA9E"),
_FLAG_NOTIFY,
)
# Defines the UART_RX characteristic
# Write or Write Without Response
# Writes data to the RX Characteristic to send it on to the UART interface.
_UART_RX = (
bluetooth.UUID("6E400002-B5A3-F393-E0A9-E50E24DCCA9E"),
_FLAG_WRITE,
)
_UART_SERVICE = (
_UART_UUID,
(_UART_TX, _UART_RX),
)
# org.bluetooth.characteristic.gap.appearance.xml
_ADV_APPEARANCE_GENERIC_COMPUTER = const(128)
class BLEUART:
def __init__(self, ble, name="arni-robot", rxbuf=100):
self._ble = ble
self._ble.active(True)
self._ble.irq(self._irq)
((self._tx_handle, self._rx_handle),) = self._ble.gatts_register_services((_UART_SERVICE,))
# Increase the size of the rx buffer and enable append mode.
self._ble.gatts_set_buffer(self._rx_handle, rxbuf, True)
self._connections = set()
self._rx_buffer = bytearray()
self._handler = None
# Optionally add services=[_UART_UUID], but this is likely to make the payload too large.
self._payload = advertising_payload(name=name, appearance=_ADV_APPEARANCE_GENERIC_COMPUTER)
self._advertise()
def irq(self, handler):
self._handler = handler
def _irq(self, event, data):
# Track connections so we can send notifications.
if event == _IRQ_CENTRAL_CONNECT:
conn_handle, _, _ = data
self._connections.add(conn_handle)
elif event == _IRQ_CENTRAL_DISCONNECT:
conn_handle, _, _ = data
if conn_handle in self._connections:
self._connections.remove(conn_handle)
# Start advertising again to allow a new connection.
self._advertise()
elif event == _IRQ_GATTS_WRITE:
conn_handle, value_handle = data
if conn_handle in self._connections and value_handle == self._rx_handle:
self._rx_buffer += self._ble.gatts_read(self._rx_handle)
if self._handler:
self._handler()
def any(self):
return len(self._rx_buffer)
def read(self, sz=None):
if not sz:
sz = len(self._rx_buffer)
result = self._rx_buffer[0:sz]
self._rx_buffer = self._rx_buffer[sz:]
return result
def write(self, data):
for conn_handle in self._connections:
self._ble.gatts_notify(conn_handle, self._tx_handle, data)
def close(self):
for conn_handle in self._connections:
self._ble.gap_disconnect(conn_handle)
self._connections.clear()
def _advertise(self, interval_us=500000):
self._ble.gap_advertise(interval_us, adv_data=self._payload)
def demo():
import time
ble = bluetooth.BLE()
uart = BLEUART(ble)
def on_rx():
# Assumes Unicode text data is being sent.
# print("rx: ", uart.read().decode().strip())
data = uart.read()
print(type(data))
print(len(data))
print(data)
# Will execute this function on every received packet
uart.irq(handler=on_rx)
try:
print("Starting BLE Nordic UART Service.")
while True:
# Just keeps the program alive
time.sleep_ms(1000)
except KeyboardInterrupt:
pass
uart.close()
if __name__ == "__main__":
demo()

@ -0,0 +1,131 @@
# This example demonstrates a peripheral implementing the Nordic UART Service (NUS).
# The Bluetooth LE GATT Nordic UART Service is a custom service that receives and writes data and serves as a bridge
# to the UART interface.
import bluetooth
from ble_advertising import advertising_payload
from micropython import const
_IRQ_CENTRAL_CONNECT = const(1)
_IRQ_CENTRAL_DISCONNECT = const(2)
_IRQ_GATTS_WRITE = const(3)
_FLAG_WRITE = const(0x0008)
_FLAG_NOTIFY = const(0x0010)
# The 128-bit vendor-specific service UUID is 6E400001-B5A3-F393-E0A9-E50E24DCCA9E (16-bit offset: 0x0001).
_UART_UUID = bluetooth.UUID("6E400001-B5A3-F393-E0A9-E50E24DCCA9E")
# Defines the UART_TX characteristic
# Notify
_UART_TX = (
bluetooth.UUID("6E400003-B5A3-F393-E0A9-E50E24DCCA9E"),
_FLAG_NOTIFY,
)
# Defines the UART_RX characteristic
# Write or Write Without Response
# Writes data to the RX Characteristic to send it on to the UART interface.
_UART_RX = (
bluetooth.UUID("6E400002-B5A3-F393-E0A9-E50E24DCCA9E"),
_FLAG_WRITE,
)
_UART_SERVICE = (
_UART_UUID,
(_UART_TX, _UART_RX),
)
# org.bluetooth.characteristic.gap.appearance.xml
_ADV_APPEARANCE_GENERIC_COMPUTER = const(128)
class BLEUART:
def __init__(self, ble, name="mpy-uart", rxbuf=100):
self._ble = ble
self._ble.active(True)
self._ble.irq(self._irq)
((self._tx_handle, self._rx_handle),) = self._ble.gatts_register_services((_UART_SERVICE,))
# Increase the size of the rx buffer and enable append mode.
self._ble.gatts_set_buffer(self._rx_handle, rxbuf, True)
self._connections = set()
self._rx_buffer = bytearray()
self._handler = None
# Optionally add services=[_UART_UUID], but this is likely to make the payload too large.
self._payload = advertising_payload(name=name, appearance=_ADV_APPEARANCE_GENERIC_COMPUTER)
self._advertise()
def irq(self, handler):
self._handler = handler
def _irq(self, event, data):
# Track connections so we can send notifications.
if event == _IRQ_CENTRAL_CONNECT:
conn_handle, _, _ = data
self._connections.add(conn_handle)
elif event == _IRQ_CENTRAL_DISCONNECT:
conn_handle, _, _ = data
if conn_handle in self._connections:
self._connections.remove(conn_handle)
# Start advertising again to allow a new connection.
self._advertise()
elif event == _IRQ_GATTS_WRITE:
conn_handle, value_handle = data
if conn_handle in self._connections and value_handle == self._rx_handle:
self._rx_buffer += self._ble.gatts_read(self._rx_handle)
if self._handler:
self._handler()
def any(self):
return len(self._rx_buffer)
def read(self, sz=None):
if not sz:
sz = len(self._rx_buffer)
result = self._rx_buffer[0:sz]
self._rx_buffer = self._rx_buffer[sz:]
return result
def write(self, data):
for conn_handle in self._connections:
self._ble.gatts_notify(conn_handle, self._tx_handle, data)
def close(self):
for conn_handle in self._connections:
self._ble.gap_disconnect(conn_handle)
self._connections.clear()
def _advertise(self, interval_us=500000):
self._ble.gap_advertise(interval_us, adv_data=self._payload)
def demo():
import time
ble = bluetooth.BLE()
uart = BLEUART(ble)
def on_rx():
# Assumes Unicode text data is being sent.
print("rx: ", uart.read().decode().strip())
# Will execute this function on every received packet
uart.irq(handler=on_rx)
nums = [4, 8, 15, 16, 23, 42]
i = 0
try:
print("Starting BLE Nordic UART Service.")
while True:
# Demonstrates the Uart write characteristic. Loops through the nums list
# transmitting one value per second.
uart.write(str(nums[i]) + "\n")
i = (i + 1) % len(nums)
time.sleep_ms(1000)
except KeyboardInterrupt:
pass
uart.close()
if __name__ == "__main__":
demo()

@ -6,4 +6,5 @@
- https://protosupplies.com/product/hc-05-zs-040-bluetooth-module/
- https://docs.micropython.org/en/latest/esp32/quickref.html#uart-serial-bus
- https://learn.adafruit.com/introducing-the-adafruit-bluefruit-le-uart-friend/command-mode-1
- https://learn.sparkfun.com/tutorials/serial-communication/rules-of-serial
- https://learn.sparkfun.com/tutorials/serial-communication/rules-of-serial
- https://learn.sparkfun.com/tutorials/terminal-basics/basic-terminology-

@ -2,4 +2,5 @@
## Resources
- [PWM L298N Article](https://howtomechatronics.com/tutorials/arduino/arduino-dc-motor-control-tutorial-l298n-pwm-h-bridge/)
- [PWM L298N Article](https://howtomechatronics.com/tutorials/arduino/arduino-dc-motor-control-tutorial-l298n-pwm-h-bridge/)
- https://out-of-cheese-error.netlify.app/l298n-with-esp8266

@ -0,0 +1,110 @@
import time
from machine import UART
#
ARNI_INITIAL_VELOCITY = 0.5
#
AXIS_STATE_UNDEFINED = 0
AXIS_STATE_IDLE = 1
AXIS_STATE_STARTUP_SEQUENCE = 2
AXIS_STATE_FULL_CALIBRATION_SEQUENCE = 3
AXIS_STATE_MOTOR_CALIBRATION = 4
AXIS_STATE_SENSORLESS_CONTROL = 5
AXIS_STATE_ENCODER_INDEX_SEARCH = 6
AXIS_STATE_ENCODER_OFFSET_CALIBRATION = 7
AXIS_STATE_CLOSED_LOOP_CONTROL = 8
# Globals
uart = UART(2, baudrate=115200, tx=17, rx=16)
current_global_velocity = ARNI_INITIAL_VELOCITY # Will be changed by controller during operation
class ArniRobot:
def __init__(self, uart, vel=None):
self._uart = uart
self._vel = vel if vel else ARNI_INITIAL_VELOCITY
self.active = False
self.initialized = False
def get(self, value):
"""Read value from odrive config.
Example:
arni.get('vbus_voltage')
"""
uart.write("r {0}\n".format(value))
if not uart.any():
time.sleep_ms(100)
value = uart.read()
if value:
value = value.decode('ascii')
return value or ''
def init_motors(self):
"""Runs index ops and sets control loop.
Must be run with the motors not under load.
"""
# AXIS_STATE_ENCODER_OFFSET_CALIBRATION = 7
uart.write('w axis0.requested_state 7\nw axis1.requested_state 7\n')
self.initialized = True
def forward(self):
"""Move forward."""
return uart.write('v 0 {0} 0\nv 1 -{0} 0\n'.format(self._vel))
def reverse(self):
"""Reverse move."""
return uart.write('v 0 -{0} 0\nv 1 {0} 0\n'.format(self._vel))
def stop(self):
"""All stop."""
return uart.write('v 0 0 0\nv 1 0 0\n')
def right(self):
"""Hard turn right."""
return uart.write('v 0 0 0\nv 1 -{0} 0\n'.format(self._vel))
def left(self):
"""Hard turn left."""
return uart.write('v 0 {0} 0\nv 1 0 0\n'.format(self._vel))
def right_forward(self):
"""Right turn while moving forward."""
return uart.write('v 0 {0} 0\nv 1 -{1} 0\n'.format(self._vel / 2, self._vel))
def right_reverse(self):
"""Right turn while moving in reverse."""
return uart.write('v 0 -{0} 0\nv 1 {1} 0\n'.format(self._vel / 2, self._vel))
def left_forward(self):
"""Left turn while moving forward."""
return uart.write('v 0 {0} 0\nv 1 -{1} 0\n'.format(self._vel, self._vel / 2))
def left_reverse(self):
"""Right turn while moving in reverse."""
return uart.write('v 0 -{0} 0\nv 1 {0} 0\n'.format(self._vel, self._vel / 2))
def set_idle(self):
"""Set motor control to idle."""
self.stop()
self.active = False
return uart.write('w axis0.requested_state {0})\nw axis1.requested_state {0}\n'.format(AXIS_STATE_IDLE))
def set_active(self):
"""Set motor control to closed loop control."""
if not self.initialized:
print("Robot motors have not been initialized. Initialize motors before entering control loop.")
self.active = True
return uart.write('w axis0.requested_state {0})\nw axis1.requested_state {0}\n'.format(AXIS_STATE_CLOSED_LOOP_CONTROL))
def set_velocity(self, velocity):
"""Set motor velocity."""
self._vel = velocity
return self._vel
arni = ArniRobot(uart)
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