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On 8/29/2014 6:20 AM, Robert Brown wrote:
Now that I have libusb working I am wanting to read string data
from the usb port on the Raspberry Pi. The string looks like :
(node sol_adv ? (p_1 0.00)(e_1 0.00)(p_2 0.00)(e_2 0.00)(p_3
0.00)(e_3 0.00)(p_4 0.00)(e_4 0.00))
(node sol_adv ? (temp_1 16.94) (temp_2 17.19) )
(node sol_adv ? (p_1 0.00)(e_1 0.00)(p_2 0.00)(e_2 0.00)(p_3
0.00)(e_3 0.00)(p_4 0.00)(e_4 0.00))
(node sol_adv ? (temp_1 16.94) (temp_2 17.19) )

as indicated using minicom

After a bit of reading I have played around with a few basic
commands but really am just stabbing in the dark with my near zero
knowledge of lua and limited programming skills.

require('libusb')
continuous=0
local buses=libusb.get_busses()
local handle=libusb.open(device)
libusb.bulk_read(handle, ENDPOINT_IN, ts, 1)

My hope is to get some basic code working and then try to merge it
into a script that has been written to read from uart and push the
data to a web site. I.e. replace the "read from uart" function.
Doubtless some will respond with "go away" but from any
patient/tolerant people out there prepared to help any tips or
pointers would be much appreciated.

USB is a bit more involved compared to serial I/O. I normally see a lot more code than that in getting a USB device running. It's better to copy from a working example, if possible. Enumerate, then open the device with the correct vendor and product ID, configure/setup, then you can perform I/O.

What is plugged into the USB port? If your hardware was previously using serial, and you are now using some FTDI-like serial-to-USB dongle, then I don't believe they are accessed via libusb, there are drivers available.

--
Cheers,
Kein-Hong Man (esq.)
Kuala Lumpur, Malaysia