How to access Kasli's EEPROM (`LOC0`)

bodokaiser

Was someone able to read and write data to the Kasli's EEPROM? I added:

device_db["eeprom"] = {
    "type": "local",
    "module": "artiq.coredevice.kasli_i2c",
    "class": "KasliEEPROM",
    "arguments": {"port": "LOC0"}
}

to the device_db and tried to run it with the following experiment

from artiq.experiment import *

class Example(EnvExperiment):
    def build(self):
        self.setattr_device("core")
        self.setattr_device("eeprom")

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

        print(eeprom.read_i32(0))

but I always receive artiq.coredevice.exceptions.I2CError: failed to ack bus address when running the experiment.

bodokaiser

@sb10q Do you have any ideas or direction to lead me to?

fsagbuya

bodokaiser Hi, if you are using Kasli v2.0, you can try to change the address of the KasliEEPROM class in Artiq to 0xae:
https://github.com/m-labs/artiq/blob/193962f31e1e4fc942f0248e0baf160cec4c8da7/artiq/coredevice/kasli_i2c.py#L35
and check if you can read from LOC0.

bodokaiser

fsagbuya Yes, changing the address to 0xae as you suggested did the trick! Is that a bug in KasliEEPROM?

fsagbuya

bodokaiser Hi. The update here now enables configuring the address from device_db: https://github.com/m-labs/artiq/commit/a8157cd5c9c8ee8cb6daa34052d300fc30583948 🙂

jry_liu

Hi, I would like to ask a further question. I am wondering is it possible to send/receive signal through SFP ports using the similar method since I see SFP ports are inside the port_mapping in kasli_i2c.py as well. Thank you!

sb10q

Yes that should work, did you try it?

jry_liu

Hi, thank you so much for your reply.

I have tried to run the following code with the latest artiq-8. I use artiq_run command in nix shell. But it seems to be not working.

device_db["SFP1"] = {
    "type": "local",
    "module": "artiq.coredevice.kasli_i2c",
    "class": "KasliEEPROM",
    "arguments": {"port": "SFP1", "address":0xae}
}

from artiq.experiment import *
class Example(EnvExperiment):
    def build(self):
        self.setattr_device("core")
        self.setattr_device("SFP1")

    @kernel
    def run(self):
        self.core.reset()
        print(self.SFP1.read_i32(0))

And I got the following error:

Traceback (most recent call first):
  File "<artiq>/coredevice/i2c.py", line 133, column 13, in artiq.coredevice.i2c.i2c_read_many(..., ...)
    raise I2CError("failed to ack bus address")
    ^
  File "test.py", line 13, in artiq_run_test.Example.run(..., ...) (RA=+0x1d4)
    print(self.SFP1.read_i32(0))
  File "<artiq>/coredevice/kasli_i2c.py", line 70, in ... artiq.coredevice.kasli_i2c.KasliEEPROM.read_i32<artiq.coredevice.kasli_i2c.KasliEEPROM>(...) (RA=+0x34c)
    i2c_read_many(self.busno, self.address, addr, data)
  File "<artiq>/coredevice/i2c.py", line 133, in ?? (RA=+0x55c)
    raise I2CError("failed to ack bus address")
artiq.coredevice.exceptions.I2CError(3): failed to ack bus address

I am wondering if it's possible to send/receive signal from SFP1 in a real time fashion, which is super helpful since we have time sensitive experiments going on in the lab.

I really appreciate any suggestions and help!

sb10q

Well do you have something on that SFP I2C bus that responds to that address? Check the signals with an oscilloscope or logic analyzer.