How to read data from a usb peripheral?
I took the wii drum that I was about to throw away. It has a USB port and I want to connect it to my macbook for a project. My goal is mainly to be able to detect when a certain drum has been triggered on a device. Based on what I have collected so far, I need to do the following steps:
- Connect the device and determine which tty port it is connected to.
- use the "screen" command to print out the data coming from the drums.
- output data from a screen command to some code that generates useful output for my project
I think I understand how to do 2 and 3, but I hung up in step 1.
If I run "ioreg -Src IOUSBDevice" in a terminal, I can determine that the device is connected, but I don't know which tty port it is on. (see below for output)
Also, in general, is it possible to print data as a byte stream from any usb peripheral connected to the USB port?
EDIT: I must add that if I run "ls / dev / tty. *" I don't see any tty.usb items, only tty.bluetooth stuff.
+-o Harmonix Drum Controller for Nintendo Wii@14200000 <class IOUSBDevice, id $
| {
| "sessionID" = 2111009401078
| "iManufacturer" = 1
| "bNumConfigurations" = 1
| "idProduct" = 5
| "bcdDevice" = 4096
| "Bus Power Available" = 250
| "bMaxPacketSize0" = 64
| "USB Product Name" = "Harmonix Drum Controller for Nintendo Wii"
| "iProduct" = 2
| "iSerialNumber" = 0
| "USB Address" = 4
| "bDeviceClass" = 0
| "locationID" = 337641472
| "bDeviceSubClass" = 0
| "IOUserClientClass" = "IOUSBDeviceUserClientV2"
| "PortNum" = 2
| "IOCFPlugInTypes" = {"9dc7b780-9ec0-11d4-a54f-000a27052861"="IOUSBFamily.$
| "bDeviceProtocol" = 0
| "USB Vendor Name" = "Licensed by Nintendo of America "
| "Device Speed" = 1
| "idVendor" = 7085
| "Requested Power" = 50
| "IOGeneralInterest" = "IOCommand is not serializable"
| "Low Power Displayed" = No
| }
|
+-o IOUSBCompositeDriver <class IOUSBCompositeDriver, id 0x100000ebe, !regis$
+-o IOUSBInterface@0 <class IOUSBInterface, id 0x100000ebf, registered, matc$
+-o IOUSBHIDDriver <class IOUSBHIDDriver, id 0x100000ec2, registered, matc$
+-o IOHIDInterface <class IOHIDInterface, id 0x100000ec4, registered, ma$
+-o IOHIDLibUserClient <class IOHIDLibUserClient, id 0x100000ec5, !regis$
+-o IOHIDLibUserClient <class IOHIDLibUserClient, id 0x100000ec7, !regis$
Still
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I don't have the exact answer you are looking for, but I ran into a similar issue while trying to read data from a GPS device connected to my MacBook Pro. In my case, after issuing the command:
ioreg -w0 -l -p IOUSB
I have (clipping non-matching parts):
+-o u-blox 7 - GPS/GNSS Receiver@14110000 <class IOUSBDevice, id 0x1000026b0, registered, matched, active, busy 0 (60 ms), retain 12>
| {
| "sessionID" = 17488341785377
| "idProduct" = 423
| "bNumConfigurations" = 1
| "iManufacturer" = 1
| "bcdDevice" = 256
| "Bus Power Available" = 250
| "bMaxPacketSize0" = 64
| "USB Product Name" = "u-blox 7 - GPS/GNSS Receiver"
| "iProduct" = 2
| "iSerialNumber" = 0
| "USB Address" = 12
| "IOUserClientClass" = "IOUSBDeviceUserClientV2"
| "bDeviceSubClass" = 0
| "bDeviceClass" = 2
| "bcdUSB" = 272
| "locationID" = 336658432
| "PortNum" = 1
| "IOCFPlugInTypes" = {"9dc7b780-9ec0-11d4-a54f-000a27052861"="IOUSBFamily.kext/Contents/PlugIns/IOUSBLib.bundle"}
| "bDeviceProtocol" = 0
| "USB Vendor Name" = "u-blox AG - www.u-blox.com"
| "Device Speed" = 1
| "idVendor" = 5446
| "Requested Power" = 50
| "IOGeneralInterest" = "IOCommand is not serializable"
| "Low Power Displayed" = No
| }
|
It doesn't tell you which device tty.*
is allocated, so I did it ls /dev/tty.*
before and after unplugging the device. After doing this, I realized that the terminal was /dev/tty.usbmodem14111
gone. You might not have one tty.usbmodem*
in your case, but note the part 14111
that overlaps with the first part of the ioreg line for my device ( u-blox 7 - GPS/GNSS Receiver@14110000
). Perhaps you can use this hint in your case to see if you are opening a tty device.
If you find a more "general" way to open tty
, share it! Good luck!
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It looks like your drum kit is identified as a HID device and not a serial / TTY port. OSX has custom HID APIs that will allow you to validate the report descriptor and collect HID reports, i.e. Events. Check out IOHIDDeviceGetReportWithCallback . Alternatively, the HID transaction API may be easier to work with as it deals with the messy business of parsing reports and descriptors for you.
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