Hi @parguello,
thanks for sharing your experiments. I see values around 100microV (10^-6 V) in your graph and this range of values looks quite normal to me.
Do you feel like the signal responds to your actions (blink, jaw clenching, occipital alpha) ?
Best,
Julien
@julienConscious said:
Hi @parguello,
thanks for sharing your experiments. I see values around 100microV (10^-6 V) in your graph and this range of values looks quite normal to me.
Do you feel like the signal responds to your actions (blink, jaw clenching, occipital alpha) ?
Best,
Julien
Sorry, perhaps I wasn't clear enough in my previous posts. I'm happy w/ the readings seen in channels 3 - 8, they're all responsive to artifacts, I see alpha waves, and the signals are in the appropriate level signifying successful gain setting. What I'm not so sanguine about is electrodes 1 and 2. As you can see in the recordings, they appear dead. I was wondering if this could be a consequence of running OpenBCI's impedance check on them; did I inadvertently kill them? If this is true, then it's a bigger mystery as to why they're active in OpenBCI GUI but not in BCI2000.
Hi again @parguello,
thanks for the clarification. If they work on the official OpenBCI GUI, it means they are ok. Performing impedance check won't kill the TP. You can try switching them from channels 1-2 to channels 3-4 for instance and see what happens. If they work, the problem is elsewhere (channel is deactivated on BCI2000 for instance). If they don't, check that the electrode is tightly screwed, double check they are correctly powered. Also, the fact that you see a value close to zero on the interface after high pass filtering does not necessarily mean the raw value is zero. It actually means that your raw signal is constant (or oscillating very slowly). If you can access the raw signal, check whether you really get raw values close to zero microV or if you are saturated (constant high absolute value like +/-187 500microV, that would possibly be identical for both channels). If you are saturated, it means the gain is too high on those channels (or was not successfully changed). That was probably what was happening for all channels when you got fV values before you contacted BCI2000 support team. A possibility is that you managed to solve the gain pb for channels 3-8 but possibly not for 1-2 yet.
Best,
Julien
Comments
Hi @parguello,
thanks for sharing your experiments. I see values around 100microV (10^-6 V) in your graph and this range of values looks quite normal to me.
Do you feel like the signal responds to your actions (blink, jaw clenching, occipital alpha) ?
Best,
Julien
Sorry, perhaps I wasn't clear enough in my previous posts. I'm happy w/ the readings seen in channels 3 - 8, they're all responsive to artifacts, I see alpha waves, and the signals are in the appropriate level signifying successful gain setting. What I'm not so sanguine about is electrodes 1 and 2. As you can see in the recordings, they appear dead. I was wondering if this could be a consequence of running OpenBCI's impedance check on them; did I inadvertently kill them? If this is true, then it's a bigger mystery as to why they're active in OpenBCI GUI but not in BCI2000.
Hi again @parguello,
thanks for the clarification. If they work on the official OpenBCI GUI, it means they are ok. Performing impedance check won't kill the TP. You can try switching them from channels 1-2 to channels 3-4 for instance and see what happens. If they work, the problem is elsewhere (channel is deactivated on BCI2000 for instance). If they don't, check that the electrode is tightly screwed, double check they are correctly powered. Also, the fact that you see a value close to zero on the interface after high pass filtering does not necessarily mean the raw value is zero. It actually means that your raw signal is constant (or oscillating very slowly). If you can access the raw signal, check whether you really get raw values close to zero microV or if you are saturated (constant high absolute value like +/-187 500microV, that would possibly be identical for both channels). If you are saturated, it means the gain is too high on those channels (or was not successfully changed). That was probably what was happening for all channels when you got fV values before you contacted BCI2000 support team. A possibility is that you managed to solve the gain pb for channels 3-8 but possibly not for 1-2 yet.
Best,
Julien