Hello all,

I am a PhD student from Granada (Spain) who has recently started using artiq on a Kasli LUH that Prof. Ospelkaus kindly sent us to get started. I've started with the examples, of course, and I am having trouble with the bidirectional TTL channels. In particular, the rtio.py example described in the documentation does nothing when using one of the bidirectional TTLs. I refer to the one shown here:

from artiq.experiment import *

class Tutorial(EnvExperiment):
    def build(self):
        self.setattr_device("core")
        self.setattr_device("ttl0")

    @kernel
    def run(self):
        self.core.reset()
        self.ttl0.output()
        for i in range(1000000):
            delay(2*us)
            self.ttl0.pulse(2*us)

This example works well with the output-only TTL channels. Since the channel is explicitly set to output mode, I don't really know what could be the issue. Input mode does work; for example, the following code results in a pulse train when a suitable signal is applied to ttl0:

from artiq.experiment import *

class Tutorial(EnvExperiment):
	def build(self):
		self.setattr_device("core")
		self.setattr_device("ttl7")
		self.setattr_device("ttl0")

	@kernel
	def run(self):
		self.core.reset()
		self.ttl7.output()

		if self.ttl0.count(self.ttl0.gate_rising(500*us)) > 20:
			detecta=True
		else:
			detecta=False

		delay(10*ms)

		if detecta:
			for i in range(100):
				self.ttl7.pulse(10*ms)
				delay(10*ms)
		else:
			print("Try again")

I am using the device_db.py file from the artiq GitHub repository in the artiq/examples/kasli_basic/ folder, in case this is relevant.

Does anyone have a suggestion on how to proceed from here?

Best,

Manu Gutiérrez