pounder_test/hitl/loopback.py

164 lines
5.2 KiB
Python

#!/usr/bin/python3
"""
Author: Vertigo Designs, Ryan Summers
Description: Loop-back integration tests for Stabilizer hardware
"""
import argparse
import asyncio
import json
import sys
from gmqtt import Client as MqttClient
from miniconf import Miniconf
# The minimum allowable loopback voltage error (difference between output set point and input
# measured value).
MINIMUM_VOLTAGE_ERROR = 0.010
def _voltage_to_machine_units(voltage):
""" Convert a voltage to IIR machine units.
Args:
voltage: The voltage to convert
Returns:
The IIR machine-units associated with the voltage.
"""
dac_range = 4.096 * 2.5
assert abs(voltage) <= dac_range, 'Voltage out-of-range'
return voltage / dac_range * 0x7FFF
def static_iir_output(output_voltage):
""" Generate IIR configuration for a static output voltage.
Args:
output_voltage: The desired static IIR output voltage.
Returns
The IIR configuration to send over Miniconf.
"""
machine_units = _voltage_to_machine_units(output_voltage)
return {
'y_min': machine_units,
'y_max': machine_units,
'y_offset': 0,
'ba': [1, 0, 0, 0, 0],
}
class TelemetryReader:
""" Helper utility to read Stabilizer telemetry. """
@classmethod
async def create(cls, prefix, broker, queue):
"""Create a connection to the broker and an MQTT device using it."""
client = MqttClient(client_id='')
await client.connect(broker)
return cls(client, prefix, queue)
def __init__(self, client, prefix, queue):
""" Constructor. """
self.client = client
self._telemetry = []
self.client.on_message = self.handle_telemetry
self._telemetry_topic = f'{prefix}/telemetry'
self.client.subscribe(self._telemetry_topic)
self.queue = queue
def handle_telemetry(self, _client, topic, payload, _qos, _properties):
""" Handle incoming telemetry messages over MQTT. """
assert topic == self._telemetry_topic
self.queue.put_nowait(json.loads(payload))
async def test_loopback(miniconf, telemetry_queue, set_point, gain=1, channel=0):
""" Test loopback operation of Stabilizer.
Note:
Loopback is tested by configuring DACs for static output and verifying telemetry reports the
ADCs are measuring those values. Output OUTx should be connected in a loopback configuration
to INx on the device.
Args:
miniconf: The miniconf configuration interface.
telemetry: a helper utility to read inbound telemetry.
set_point: The desired output voltage to test.
channel: The loopback channel to test on. Either 0 or 1.
gain: The desired AFE gain.
"""
print(f'Testing loopback for Vout = {set_point:.2f}, Gain = x{gain}')
print('---------------------------------')
# Configure the AFE and IIRs to output at the set point
await miniconf.command(f'afe/{channel}', f'G{gain}', retain=False)
await miniconf.command(f'iir_ch/{channel}/0', static_iir_output(set_point), retain=False)
# Configure signal generators to not affect the test.
await miniconf.command('signal_generator/0/amplitude', 0, retain=False)
# Wait for telemetry to update.
await asyncio.sleep(5.0)
# Verify the ADCs are receiving the setpoint voltage.
tolerance = max(0.05 * set_point, MINIMUM_VOLTAGE_ERROR)
latest_values = await telemetry_queue.get()
print(f'Latest telemtry: {latest_values}')
assert abs(latest_values['adcs'][channel] - set_point) < tolerance
print('PASS')
print('')
def main():
""" Main program entry point. """
parser = argparse.ArgumentParser(description='Loopback tests for Stabilizer HITL testing',)
parser.add_argument('prefix', type=str,
help='The MQTT topic prefix of the target')
parser.add_argument('--broker', '-b', default='mqtt', type=str,
help='The MQTT broker address')
args = parser.parse_args()
telemetry_queue = asyncio.LifoQueue()
async def telemetry():
await TelemetryReader.create(args.prefix, args.broker, telemetry_queue)
try:
while True:
await asyncio.sleep(1)
except asyncio.CancelledError:
pass
telemetry_task = asyncio.Task(telemetry())
async def test():
""" The actual testing being completed. """
interface = await Miniconf.create(args.prefix, args.broker)
# Disable IIR holds and configure the telemetry rate.
await interface.command('allow_hold', False, retain=False)
await interface.command('force_hold', False, retain=False)
await interface.command('telemetry_period', 1, retain=False)
# Test loopback with a static 1V output of the DACs.
await test_loopback(interface, telemetry_queue, 1.0)
# Repeat test with AFE = 2x
await test_loopback(interface, telemetry_queue, 1.0, gain=2)
# Test with 0V output
await test_loopback(interface, telemetry_queue, 0.0)
telemetry_task.cancel()
loop = asyncio.get_event_loop()
sys.exit(loop.run_until_complete(test()))
if __name__ == '__main__':
main()