Add HCI Cast Lib & PyYaml

HCI Cast yet to be tested / debugged
PyYaml to ingest secrets file
This commit is contained in:
Aadi Desai 2022-02-18 17:43:49 +00:00
parent d758ed6f97
commit 69d2e7e2a1
No known key found for this signature in database
GPG key ID: CFFFE425830EF4D9
4 changed files with 92 additions and 4 deletions

3
.gitignore vendored
View file

@ -153,3 +153,6 @@ cython_debug/
# VSCode # VSCode
.vscode/ .vscode/
# Secrets file
.secrets.yml

73
hci.py Normal file
View file

@ -0,0 +1,73 @@
import base64
import subprocess
from time import sleep
from struct import pack
class HCIBroadcaster:
def __init__(self, b64key):
self.key = base64.b64decode(b64key)
def _advertisement_template():
adv = ""
adv += "1e" # length (30)
adv += "ff" # manufacturer specific data
adv += "4c00" # company ID (Apple)
adv += "1219" # offline finding type and length
adv += "00" # state
for _ in range(22): # key[6:28]
adv += "00"
adv += "00" # first two bits of key[0]
adv += "00" # hint
return bytearray.fromhex(adv)
def _bytes_to_strarray(self, bytes_, with_prefix=False):
if with_prefix:
return [hex(b) for b in bytes_]
else:
return [format(b, "x") for b in bytes_]
def _run_hci_cmd(self, cmd, hci="hci0", wait=1):
cmd_ = ["hcitool", "-i", hci, "cmd"]
cmd_ += cmd
print(cmd_)
subprocess.run(cmd_)
if wait > 0:
sleep(wait)
def start_advertising(self, interval_ms=2000):
key = self.key
addr = bytearray(key[:6])
addr[0] |= 0b11000000
adv = self._advertisement_template()
adv[7:29] = key[6:28]
adv[29] = key[0] >> 6
print(f"key ({len(key):2}) {key.hex()}")
print(f"address ({len(addr):2}) {addr.hex()}")
print(f"payload ({len(adv):2}) {adv.hex()}")
# Set BLE address
self._run_hci_cmd(
["0x3f", "0x001"] + self._bytes_to_strarray(addr, with_prefix=True)[::-1]
)
subprocess.run(["systemctl", "restart", "bluetooth"])
sleep(1)
# Set BLE advertisement payload
self._run_hci_cmd(
["0x08", "0x0008"] + [format(len(adv), "x")] + self._bytes_to_strarray(adv)
)
# Set BLE advertising mode
interval_enc = pack("<h", interval_ms)
hci_set_adv_params = ["0x08", "0x0006"]
hci_set_adv_params += self._bytes_to_strarray(interval_enc)
hci_set_adv_params += self._bytes_to_strarray(interval_enc)
hci_set_adv_params += ["03", "00", "00", "00", "00", "00", "00", "00", "00"]
hci_set_adv_params += ["07", "00"]
self._run_hci_cmd(hci_set_adv_params)
# Start BLE advertising
self._run_hci_cmd(["0x08", "0x000a"] + ["01"], wait=0)

17
main.py
View file

@ -1,7 +1,9 @@
from time import sleep from time import sleep
import yaml
import smbus2 import smbus2
import si7201 import si7201
import tmp006 import tmp006
import hci
bus = smbus2.SMBus(1) # set up I2C bus 1 bus = smbus2.SMBus(1) # set up I2C bus 1
@ -20,7 +22,16 @@ print(irtempsensor.manID) # read the manufacturer ID and print
print(irtempsensor.devID) # read the device ID and print print(irtempsensor.devID) # read the device ID and print
print(irtempsensor.temperature) # read the temperature and print print(irtempsensor.temperature) # read the temperature and print
print("========= TMP006 Test Loop =========") print("========= Testing HCI Cast =========")
with open(".secrets.yml", "r") as secrets:
try:
secrets = yaml.safe_load(secrets)
key = secrets["key"] # Get Base64 encoded device public key from secrets file
except yaml.YAMLError as exc:
print(exc)
btcast = hci.HCIBroadcaster(key) # set up HCI Broadcaster
btcast.start_advertising(5000) # start advertising with interval of 5 seconds
while True: while True:
print(irtempsensor.temperature) # read the temperature and print btcast.start_advertising(5000) # start advertising with interval of 5 seconds
sleep(1) # wait for 1 second

View file

@ -1,3 +1,4 @@
colorzero==2.0 colorzero==2.0
gpiozero==1.6.2 gpiozero==1.6.2
PyYAML==6.0
smbus2==0.4.1 smbus2==0.4.1