how to connect a buffer rx() to the ADC?

[karu2003]

how to connect a buffer rx() to the ADC?

I did it by analogy with other ADCs, but it doesn’t work.

target_device = "ad7476a"
samples = 100
dev = ctx.find_device(target_device)
buf = iio.Buffer(dev, samples)

or add to class init rx.init(self)

 ADC = ad7476.ad7476a("ip:analog.local")
 ADC.rx_buffer_size = samples
 ADC.rx_enabled_channels = [ad_channel]
 data = ADC.rx()

I get an error

analog@analog:~/rpi_ad7476 $ /usr/bin/python3 /home/analog/rpi_ad7476/ad7476.py Traceback (most recent call last): File "/home/analog/rpi_ad7476/ad7476.py", line 65, in buf = iio.Buffer(dev, samples) File "/usr/local/lib/python3.9/dist-packages/iio.py", line 981, in init self._buffer = _create_buffer(device._device, samples_count, cyclic) File "/usr/local/lib/python3.9/dist-packages/iio.py", line 56, in _check_null raise OSError(err, _strerror(err)) OSError: [Errno 22] Invalid argument

<<<<<<<<<<<<<<<<<<<<<<<<<

Traceback (most recent call last): File "/home/analog/rpi_ad7476/ad7476.py", line 63, in data = ADC.rx() File "/home/analog/.local/lib/python3.9/site-packages/adi/rx_tx.py", line 295, in rx data = self.rx_non_complex() File "/home/analog/.local/lib/python3.9/site-packages/adi/rx_tx.py", line 268, in rx_non_complex x = self.rx_buffered_data() File "/home/analog/.local/lib/python3.9/site-packages/adi/rx_tx.py", line 234, in rx_buffered_data self._rx_init_channels() File "/home/analog/.local/lib/python3.9/site-packages/adi/rx_tx.py", line 197, in _rx_init_channels self.__rxbuf = iio.Buffer(self._rxadc, self.rx_buffer_size, False) File "/usr/local/lib/python3.9/dist-packages/iio.py", line 981, in init__ self._buffer = _create_buffer(device._device, samples_count, cyclic) File "/usr/local/lib/python3.9/dist-packages/iio.py", line 56, in _check_null raise OSError(err, _strerror(err)) OSError: [Errno 22] Invalid argument

[tfcollins]

You need to enable valid channels in both cases before creating buffers. In the pyadi example you are enabling channel 1 which does not exist. Try enabling channel 0

[karu2003]

The problem is not the channel number. To test them, I have two channels and the voltage is on channel 1. I switched to version 0.25. There was a problem with permission denied. i need to find a way to make this accessible to all users.

I installed the trigger manuel. modprobe iio_trig_sysfs cd /sys/bus/iio/devices/iio_sysfs_trigger echo 123 > add_trigger cd /sys/bus/iio/devices/trigger0 cat name # should give sysfstrig123 cd /sys/bus/iio/devices/iio:device0 echo sysfstrig123 > trigger/current_trigger echo 1 > scan_elements/in_voltage0_en echo 1 > buffer/enable

Now i have two problems. "High-speed mode not enabled" and "Connection timed out"

analog@analog:~/ad7476_025 $ /usr/bin/python3 /home/analog/ad7476_025/ad7476.py WARNING: High-speed mode not enabled Traceback (most recent call last): File "/home/analog/ad7476_025/ad7476.py", line 99, in data = ADC.rx() File "/home/analog/.local/lib/python3.9/site-packages/adi/rx_tx.py", line 295, in rx data = self.rx_non_complex() File "/home/analog/.local/lib/python3.9/site-packages/adi/rx_tx.py", line 268, in rx_non_complex x = self.rx_buffered_data() File "/home/analog/.local/lib/python3.9/site-packages/adi/rx_tx.py", line 235, in rx_buffered_data self.__rxbuf.refill() File "/home/analog/.local/lib/python3.9/site-packages/iio.py", line 1003, in refill _buffer_refill(self._buffer) File "/home/analog/.local/lib/python3.9/site-packages/iio.py", line 62, in _check_negative raise OSError(-result, _strerror(-result)) TimeoutError: [Errno 110] Connection timed out

[tfcollins]

Before you changed to the dynamic changes here https://github.com/karu2003/rpi_ad7476/commit/0eabfdef687148024c50cb186f4083f920d9b728 you were indexing into an undefined channel. Be aware with dynamic channels there is no guarantee of channel ordering.

For the other two issues, your device does not support high speed mode so you can do anything. Please ignore the warning. As for the timeout, you likely need to configure a trigger for the device during the init

[karu2003]

Before christmas I figured out how to use a trigger and a buffer. :) https://github.com/karu2003/rpi_ad7476