******************************
* Hifive stuff
******************************

   https://www.sifive.com/boards

******************************
It seems that libftdi is best documented in :

  file:///usr/share/doc/libftdi-dev/html/ftdi_8c.html

The main functions we need 


See : https://www.huitsing.nl/irftdi/test2.c





struct ftdi_context ftdic;

ftdi_init(&ftdic);







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* 03/28/2019
******************************

Some simple programs to use libftdi can be found in :

/usr/share/doc/libftdi-dev/examples


Notice that when you plug an ftdi board into the USB, using FT_Prog, or just looking at the virtual machine Devices-->USB you can hover over the FTDI device, and see the VendorID=0403 and ProductID=6001

If you now copy simple.c and compile it as :



-----
gcc simple.c -lftdi

a.out

greg@carbox:~/ftdiWork$ a.out
ftdi_read_chipid: 0
FTDI chipid: 6B863D57

------

Now compiling 

gcc baud_test.c -lftdi


greg@carbox:~/ftdiWork$ a.out -p "i:0x0403:0x6001" -d 32768 -b 153600 -m r
real baudrate used: 153600
this test should take 2.13 seconds
and took 2.1686 seconds, this is 151101 baud or factor 0.984



greg@carbox:~/ftdiWork$ a.out -p "i:0x0403:0x6001" -d 32768 -b 9600 -m r
real baudrate used: 9600
this test should take 34.13 seconds
and took 33.9997 seconds, this is 9638 baud or factor 1.004







Good overview of serial port :  https://www.mathworks.com/help/instrument/serial-port-overview.html

Excellent article : https://www.swharden.com/wp/2018-06-03-bit-bang-ftdi-usb-to-serial-converters-to-drive-spi-devices/

(beware of FT232R in bit bang mode. Use FT232H)



Check out minicom -

https://medium.com/@amitasinghchauhan/serial-port-debugging-101-loopback-test-4a7e40da9055

Start it with minicom -s
Turn flow control off
Then hook to /dev/ttyUSB0



* *********************************************************************
After all of this, you can run python without being sudo :

greg@carbox:~/pwork$ python -m pylibftdi.examples.list_devices
FTDI:FT232R USB UART:AK06VDT0
greg@carbox:~/pwork$ 
* *********************************************************************





See this webpage for info on standard debian groups
https://wiki.debian.org/SystemGroups

sudo adduser greg dialout
groups



greg@carbox:~/pwork$ lsusb
Bus 001 Device 003: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC
Bus 001 Device 002: ID 80ee:0021 VirtualBox USB Tablet
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub



greg@carbox:~/pwork$ sudo python -m pylibftdi.examples.list_devices
FTDI:FT232R USB UART:AK06VDT0
greg@carbox:~/pwork$ sudo vim /etc/udev/rules.d/99-libftdi.rules
greg@carbox:~/pwork$ cat /etc/udev/rules.d/99-libftdi.rules
SUBSYSTEMS=="usb", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6001", GROUP="dialout", MODE="0660"
SUBSYSTEMS=="usb", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6014", GROUP="dialout", MODE="0660"






https://pylibftdi.readthedocs.io/en/0.15.0/installation.html#linux




sudo apt install python-pip

pip install pylibftdi

sudo apt-get install libftdi-dev


sudo python -m pylibftdi.examples.list_devices


Need to fix permission problem

Also, note, you must enable the device in the virtual machine in the Devices Tab at the top





http://physics.oregonstate.edu/~hetheriw/whiki/py/sys/21.php

I have the FTDI FT232R

Hopefully I can get it to work with python