Air puff

Bowey

Hi Josh,

I wonder if there's a way to deliver air puff via the solenoid valve controlled by Bpod? If so, what will be the parameter fit for this purpose?

Best,
Bowen

Josh

Hi Bowen,

Our solenoid valves (from The Lee Company, here) can gate pressurized air. The standard setup is to use a flow meter (e.g. this) to regulate the flow to 1 liter per minute into the top port of the valve. Next, remove the sleeve from the bottom valve port - this will be your exhaust. By default, the flow will go to exhaust, but then the valve is energized, flow will switch to the middle port, which you'd route to the experimental chamber.

-Josh

stan94

Josh
Hi Josh, we are also using solenoid valve to control the air flow. Since the Behavior port has been used by other valves in our system, we decide to use Bnc Out. However, after we connected the valve to this channel and turned on the BncOut in the Bpod console, nothing happened (as we were just testing by blowing the air to the top port and see if anything shows up to the middle port). We've also tried to switch the coil connection just in case it's wrong. Can you please help us?

Best,
Songyuan

Bowey

Josh wrote[quote='Josh' pid='1209' dateline='1570473534']
Hi Bowen,

Our solenoid valves (from The Lee Company, here) can gate pressurized air. The standard setup is to use a flow meter (e.g. this) to regulate the flow to 1 liter per minute into the top port of the valve. Next, remove the sleeve from the bottom valve port - this will be your exhaust. By default, the flow will go to exhaust, but then the valve is energized, flow will switch to the middle port, which you'd route to the experimental chamber.

-Josh

Thank you Josh!

Josh

Hello Songyuan,

The BNC output channels supply 5V, and a nominal amount of current to drive logic gates and optoisolators. To drive a solenoid valve, you need 12V and much higher current. You also need components to protect the circuitry from reverse voltage spikes on turning off the inductive load.

If you've used all of the valve driver channels (one per behavior port) you can add additional valves with the valve driver module. Each module adds control for 8 valves.

Josh

stan94

Josh
Thank you Josh. Do you have any protection components to recommend?

Songyuan

Josh

That would depend on your drive circuit. Do you have a schematic?

stan94

Josh
Hi Josh, we don't have an existing schematic yet, but our circuit is quiet simple. It's a Bpod r2.5 (right now) connected to a Port Interface board through behavior port 1, this board is connected to a dispenser valve from another company. Other behavior ports are free right now.

Another thing I just encountered is, we were trying to use behavior port 2 with our air puff solenoid valve through a ethernet cable. However, there are 4 pairs at the end of the cable. When I was testing to connect one pair of them to the valve, the whole Bpod just got shut down and cannot be turned on even after unplugging and replugging. Do you know what might happened?

Josh

Hello Songyuan,

If you use the 'Valve' channel on the port interface board, you don't need protection components. Those are only necessary if you are building your own valve driver circuit, to be gated by the state machine's 5V TTL output.

The state machine's port interface has I/O lines (Ethernet pins 1, 2, 3, 4) that are not 12V tolerant. Pins 1, 2 and 3 are not 5V tolerant. If you shorted 5V or 12V to those lines, you may have damaged the Teensy microcontroller.

If the damage was limited to firmware corruption, you can attempt to rescue it by pressing the white button on the Teensy board. This will put the device in bootloader mode. You'd then use LoadBpodFirmware() at the MATLAB command line to re-load the firmware. Unfortunately if the damage is physical (more likely in an over-voltage situation) it can't be rescued.

Please let me know what you find.

Thanks,

Josh

stan94

Josh
Thank you Josh.
I tried to press (also long press) the white button on the Teensy board and nothing happened. So I assume that I probably damaged the microcontroller. Last time (in response to my previous message), I connected to solenoid ethernet cable to the behavior port 2 and tested the valve. Is there any way to fix the teensy board? And do you have any recommend ethernet cable that connects the Bpod behavior port to solenoid valve (while I would like to use the 'Valve' and the code to activate the Valve)?

Best,
Songyuan

Josh

Hello Songyuan,

Unfortuantely I do not know what else can be done to rescue the Teensy board. It's possible that the Ethernet cable's 12V line was shorted to a non-12V tolerant Teensy pin. To help prevent this in the future, I recommend terminating the Ethernet cable with a port interface board or an Ethernet breakout board + jack. The cable is a standard CAT5e or CAT6 Ethernet cable, up to 2m long. Our web shop has a 1m cable and industrial suppliers like Digikey and Mouser have tons of additional options.

Josh

stan94

Josh
Thank you Josh. Just want to double check that in this case we can just connect the ethernet cable to any behavior port on Bpod and the jack on the teensy board right?

Songyuan

Josh

Which jack on the Teensy board? Are you referring to the Bpod Teensy Shield? If so it needs to connect to a module port, not a behavior port.

-Josh

stan94

Josh
Hi Josh, sorry for my description. Now I connected the solenoid valve on the port interface board jack though an ethernet cable to behavior port 2, and when I turn on behavior port 2 in the Bpod console, it does open the solenoid valve successfully. Now we have two valves connected to Bpod, is there any script we can use to open them in different circumstances?

Songyuan

Josh

Hello Songyuan,

In any state where you want the valve to be open, add {'Valve2', 1} to the "Output Actions" section of the state description. An example state description with no output actions is shown here.

-Josh