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suservo: refrain from generating channel list 

For consistency with other DDS examples that uses multiple channels.
e.g. TTL relay external trigger, DDS synchronization
This commit is contained in:
occheung 2022-01-20 16:48:55 +08:00
parent 8404fed3da
commit ac8d398f5e
2 changed files with 9 additions and 11 deletions
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8
4410-4412.tex
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@ -821,16 +821,16 @@ In the following example, the amplitude of DDS is proportional to the ADC input
First, initialize the RTIO, SU-Servo and its channel.
Note that the programmable gain of the Sampler is $10^0=1$, the input range is [-10V, 10V].
\inputcolorboxminted{firstline=14,lastline=21}{examples/suservo.py}
\inputcolorboxminted{firstline=12,lastline=19}{examples/suservo.py}
Next, setup the PI control as an IIR filter. It has -1 proportional gain $k_p$ and no integrator gain $k_i$.
\inputcolorboxminted{firstline=22,lastline=29}{examples/suservo.py}
\inputcolorboxminted{firstline=20,lastline=27}{examples/suservo.py}
Then, configure the DDS frequency to 10 MHz with 3V input offset.
When input voltage $\geq$ offset voltage, the DDS output amplitude is 0.
\inputcolorboxminted{firstline=30,lastline=34}{examples/suservo.py}
\inputcolorboxminted{firstline=28,lastline=32}{examples/suservo.py}
SU-Servo encodes the ADC voltage in a linear scale [-1, 1].
Therefore, 3V is converted to 0.3.
@ -838,7 +838,7 @@ Note that the ASF of all DDS channels are capped at 1.0, the amplitude clips whe
Finally, enable the SU-Servo channel with the IIR filter programmed beforehand.
\inputcolorboxminted{firstline=36,lastline=37}{examples/suservo.py}
\inputcolorboxminted{firstline=34,lastline=35}{examples/suservo.py}
A 10 MHz DDS signal is generated from the example above, with amplitude controllable by ADC.
The RMS voltage of the DDS channel against the ADC voltage is plotted.

12
examples/suservo.py
View File

@ -7,9 +7,7 @@ class SUServoExample(EnvExperiment):
def build(self):
self.setattr_device("core")
self.suservo = self.get_device("suservo0")
self.suschannels = [
self.get_device("suservo0_ch0")
]
self.suschannel0 = self.get_device("suservo0_ch0")
@kernel
def run(self):
@ -18,8 +16,8 @@ class SUServoExample(EnvExperiment):
self.suservo.init()
self.suservo.set_pgia_mu(0, 0) # unity gain
self.suservo.cplds[0].set_att(0, 15.)
self.suschannels[0].set_y(profile=0, y=0.) # Clear integrator
self.suschannels[0].set_iir(
self.suschannel0.set_y(profile=0, y=0.) # Clear integrator
self.suschannel0.set_iir(
profile=0,
adc=0, # take data from Sampler channel 0
kp=-1., # -1 P gain
@ -27,11 +25,11 @@ class SUServoExample(EnvExperiment):
g=0., # no integrator gain limit
delay=0. # no IIR update delay after enabling
)
self.suschannels[0].set_dds(
self.suschannel0.set_dds(
profile=0,
offset=-.3, # 3 V with above PGIA settings
frequency=10*MHz,
phase=0.)
# enable RF, IIR updates and set profile
self.suschannels[0].set(en_out=1, en_iir=1, profile=0)
self.suschannel0.set(en_out=1, en_iir=1, profile=0)
self.suservo.set_config(enable=1)