Hi everyone,
I am using a LM3S5951 controllers for one of my projects in which I need to implement a host side driver for Dot Matrix printer .
I am done with enumeration of the printer, but now I would like to know how can I send data to printers using bulk transfers. I am using the Stellaries USB Library for the same where I found some host side codes for keyboard and pendrive. I would like to know, how to go about this.
Regards
Dhanush
Hi Tsuneo,
Thank you for your responses. I have implemented the above things as said but whenever I read the status using GetPortStatus function described above I get result byte as '0' even if the paper is not present in the printer.
The procedure I followed for the same is as follows:
1: I added the implementation as discussed above to my printerhostclass.c file as it is. I understood the things mentioned in it.
2: I have created an instance of the printer driver g_ulPRNinstance.
3: unsigned long status=GetPortStatus(g_ulPRNinstance,0) I call the function using the above line from my main function. if((status & 0x20)== 1) do this else do that.
Now when I start the printer w/o paper and call this function then always it executes the "else" part, where as it should execute "if" part. I check the value of status on uart but it shows 0. Am I doing something wrong here, if yes then what should I do
First off, you say you get the status '0'. But the status is a number - not a character. While character '0' happens to be 0x20 + 0x10;
Next thing - your expression:
if((status & 0x20)== 1) { ... }
is broken. It can never be true.
It should either be:
if (status & 0x20) { ... }
or
if ((status & 0x20) != 0) { ... }
Hi,
Ok. But after calling function Getportstatus, I get ulstatus I check this thing by displaying it on serial terminal after converting long to Ascii, still I get 0. I want to know whether I am calling the func correctly using the correct parameters, and what should be the wvalue parameter.
There is note in USB Printing Device Class spec stating that some printer do not support this information. And what does benign status, what does it mean. My printer is Epson-LX300-II does this support the thing or not.
As mentioned by Mr. Dhanush, when I tried it the printer was returning some status. When I converted to ascii and sent it serially to hyper terminal I saw data as 87(10000111) which I guess is wrong since all the bits which are high are reserved, which should not be the case.
Still I am debugging this thing whether I am doing somethin wrong. Hoping for some hints.
Regards Sagar
Connect your printer to a PC, on which genuine printer driver is installed, and trace the USB traffic using a sniffer. The driver should poll the printer status.
a) How does the driver poll the status, over GET_PORT_STATUS request, or over the bulk IN endpoint?
b) How does the status change, at on/off of "Select" button, and Paper empty?
Tsuneo
HI,
Here instead of calling the getportstatus every 100 ms i call the func before printing the data.
Now when I first send data to be printed w/o paper inserted i get no error i.e. 00011000 .
Second time if I do the same i get error i.e. 00110000
My question is why it does not give an error for the first time.
And my requirement is once i give data to be printed and no paper is inserted it the code should wait till the paper is not inserted and once the paper is inserted it should start printing.
For parallel port I do this using the busy flag of the centronics port. I keep on checking the busy flag till it gets low, Once the paper is inserted the printer makes the busy flag zero and then I start sending data to be printed.
How can I achieve this on USB . I Know the only way I have is polling the printer status continuously.
Regards Dhanush
Did you trace the USB traffic of the "genuine" PC driver for the printer? You can trace it with any free USB sniffer, like http://freeusbanalyzer.com/ sourceforge.net/.../ etc.
The "genuine" PC driver should regularly poll the printer status. It may apply bulk IN endpoint or any vendor-specific request other than GET_PORT_STATUS.
I want to implement a USB module as V drive for pendrive where I can get commands through uart such as make directory ,open file etc and then dump the file onto pendrive. I am aware of how USB works, I want to know the feasibility of this project and a starting guide to how can it be achieved.
Regards Sanket
I am using a TM4c123 series controllers with 1 USB host port. Now I am using the same port using the a USB switch to use the keyboard and pendrive. But i want to use them both without switching. I guess this is possible if a USB HUB controller with 2 or 3 downstream ports is available. So how should go about it, are there any controllers which such capabilities available.
Sanket