Simple example codes for dlpc900

Hi Paolo,

We do not currently have any example code available other than those shown in the Programmer's Guide.

Perhaps someone from the E2E Community would be willing to post an example.

If you have any specific questions regarding HIDs or programming the DLPC900, I would be happy to answer them.

Best regards,
Trevor

Dear Trevor,

ok, i hope he community will help :)

In the meantime, my main problem with the guide i linked is how to send to the device an "API level readfile", which is needed to perform read operations. The guide only uses those three words, and i struggle to find a way to do it in practice. Any further description of what an API level readfile is would be immensely useful.

Moreover, can you confirm that all the "commands" should be 65 bytes long? In the guide it seems that they can be shorter, but if i try sending a shorter package, an error message is raised. In case i need to send a shorter command, should i fill the remaining bits with 0x00s?

Thanks for your help

Paolo

Hi Nathan,

Thank you, your post is exactly what i was looking for! When you are satisfied with the code you should consider making it public on something like github, as far as i know it is the only example free code for the control of dlpc900 based devices.

By the way, in the meantime i managed to create a basic input-output interface in python with the pyusb library.

You can find it at the end of this message (for some reason the ti forum doesn't allow atachment of py files), in case any future developer ends up here by googleing "python dlpc900". It is just a basic interface, allowing the user to send usb commands specifying:

-write or read command

-a sequential byte for readout check

-the usb control bytes

-the payload data

and to read out the responses of the dlp as a series of bytes. It includes the example read and write commands in the guide, plus two functions for "power mode" switching.

It should be enough to get a user with no clues about usb interface started. Remember the pyusb library requires the libusb0.dll file in your windows/system32 folder.

python code:

import usb.core
import usb.util


class dmd():
    def __init__(self):
        self.dev=usb.core.find(idVendor=0x0451 ,idProduct=0xc900 )

        self.dev.set_configuration()

    def command(self,mode,reply,sequencebyte,com1,com2,data=None):
        buffer = [0x00]*64

        flagstring=''
        if mode=='r':
            flagstring+='1'
        else:
            flagstring+='0'
        if reply:
            flagstring+='1'
        else:
            flagstring+='0'
        flagstring+='000000'
        buffer[0]=int(flagstring,2)
        buffer[1]=sequencebyte
        len1=2+len(data)
        if len1>254:
            len2=(2+len(data))/255
            len1=len1-len2
        else:
            len2=0
        buffer[2]=len1
        buffer[3]=len2
        buffer[4]=com2
        buffer[5]=com1
        for i in range(len(data)):
            buffer[6+i]=data[i]


        self.dev.write(1, buffer)

    def readreply(self):
        a=self.dev.read(0x81,64)
        for i in a:
            print hex(i)

    def idle_on(self):
        self.command('w',False,0x00,0x02,0x01,[int('00000001',2)])

    def idle_off(self):
        self.command('w',False,0x00,0x02,0x01,[int('00000000',2)])

    def standby(self):
        self.command('w',False,0x00,0x02,0x00,[int('00000001',2)])

    def wakeup(self):
        self.command('w',False,0x00,0x02,0x00,[int('00000000',2)])

    def testread(self):
        self.command('r',True,0xff,0x11,0x00,[])
        self.readreply()

    def testwrite(self):
        self.command('w',True,0x22,0x11,0x00,[0xff,0x01,0xff,0x01,0xff,0x01])




dlp6500=dmd()


dlp6500.wakeup()

dlp6500.testwrite()

dlp6500.testread()

dlp6500.standby()

Thank you for sharing Nathan and Paolo! I am sure that these examples will be helpful for future dlpc900 developers!

Best regards,
Trevor