USB printer class

[spa23]

Posted on November 04, 2013 at 12:10

Hi u guys

I have in a old powerpoint slide from ST, seen that ST can provide a usb printer Class, does anyone know if the can and/or where to find it?

Best regards.

 

#usb-printer

[Amel NASRI]

Posted on November 06, 2013 at 14:00

Hi Soeren,

Unfortunately, we don't have an implementation of the USB printer class.

But, starting from our other classes like CDC or MassStorage, you should get it by your self.

-Mayla-

[Palauqui.Georges]

Posted on August 12, 2014 at 11:43

Dear Panduro Soeren,

We are very interested to know if you managed to write your own USB Printer Class ?

We are trying to do so based on STM32Cube and the USB Host Library from ST. Any work we can do in common ?

Best Regards,

Georges

[tsuneo]

Posted on August 12, 2014 at 20:08

Hi GPTechinno,

> We are very interested to know if you managed to write your own USB Printer Class ? > We are trying to do so based on STM32Cube As ST’s staff said in above post, you may start with one of existing host class driver implementation, like MSC (Mass-Storage Class). But surely, just showing a starting point isn’t helpful answer ;) You’ll need some guidance, how to modify the implementation. Here is brief outline of modification, based on STM32Cube_FW_F4_V1.3.0 0) Start with - \STM32Cube_FW_F4_V1.3.0\Projects\STM324xG_EVAL\Applications\USB_Host\MSC_Standalone\Src\main.c - \STM32Cube_FW_F4_V1.3.0\Middlewares\ST\STM32_USB_Host_Library\Class\MSC\Src\usbh_msc.c 1) make Class driver object (structure instance), and register it usbh_msc.c defines this class driver structure

usbh_msc.c
USBH_ClassTypeDef USBH_msc =
{
''MSC'',
USB_MSC_CLASS,
USBH_MSC_InterfaceInit,
USBH_MSC_InterfaceDeInit,
USBH_MSC_ClassRequest,
USBH_MSC_Process,
USBH_MSC_SOFProcess,
NULL,
};
usbh_msc.h
/* MSC Class Codes */
#define USB_MSC_CLASS 0x08
extern USBH_ClassTypeDef USBH_msc;
#define USBH_MSC_CLASS &USBH_msc

This structure is modified for printer class, by replacing ''MSC'' to ''PRN'', like

#define USB_PRN_CLASS 0x07
extern USBH_ClassTypeDef USBH_prn;
#define USBH_PRN_CLASS &USBH_prn
USBH_ClassTypeDef USBH_prn =
{
''MSC'',
USB_PRN_CLASS,
USBH_PRN_InterfaceInit,
USBH_PRN_InterfaceDeInit,
USBH_PRN_ClassRequest,
USBH_PRN_Process,
USBH_PRN_SOFProcess,
NULL,
};

main.c registers this class driver object.

main.c
int main(void)
{
...
/* Add Supported Class */
//USBH_RegisterClass(&hUSBHost, USBH_MSC_CLASS);
USBH_RegisterClass(&hUSBHost, USBH_PRN_CLASS);

2) code class driver routines 2-1) USBH_PRN_InterfaceInit() <- USBH_MSC_InterfaceInit() This routine find printer interface on the descriptor set using USBH_FindInterface()

//interface = USBH_FindInterface(phost, phost->pActiveClass->ClassCode, MSC_TRANSPARENT, MSC_BOT);
#define PRN_PRINTERS 0x01 // sub-class
#define PRN_UNIDIRECTIONAL 0x01 // protocols
#define PRN_BIDIRECTIONAL 0x02
#define PRN_1284_4 0x03
#define PRN_VENDOR 0xFF
interface = USBH_FindInterface(phost, phost->pActiveClass->ClassCode, PRN_PRINTERS, PRN_BIDIRECTIONAL);

Your target printer may have other class-protocol value than PRN_BIDIRECTIONAL. Find it using a utility, like USBView http://www.ftdichip.com/Support/Utilities/usbview.zip The rest of code lines are (almost) usable as is, except - replace every ''MSC'' into ''PRN'' on the variable names - you don’t need these MSC-specific code lines in this routine.

MSC_Handle->current_lun = 0;
MSC_Handle->rw_lun = 0;
USBH_MSC_BOT_Init(phost);
/* De-Initialize LUNs information */
USBH_memset(MSC_Handle->unit, 0, sizeof(MSC_Handle->unit));

2-2) USBH_PRN_InterfaceDeInit() <- USBH_MSC_InterfaceDeInit() No change required. 2-3) USBH_PRN_ClassRequest() <- USBH_MSC_ClassRequest() In the code lines under ''case MSC_REQ_GET_MAX_LUN:'', the original puts Get_Max_Lun request to the target USB stick. Instead, GET_DEVICE_ID request is put to the printer. By GET_DEVICE_ID request, the printer returns DEVICE_ID string, which holds supported PDLs (Page Description Language) after ''CMD:'' tag. You need a ''PCL'' printer, as you said your other post. Confirm the printer should support one of ''PCL'' protocols. For DEVICE_ID string, refer to this port. http://www.keil.com/forum/57021/ 2-4) USBH_PRN_Process() <- USBH_MSC_Process() This routine is repeatedly called by the main loop, by USBH_Process(), to run the class. The original code is fully MSC-specific. Then rewrite entire code lines. For printer class, the printer status (paper empty, on-line, error) is retrieved by GET_PORT_STATUS request 2-5) The PCL data is sent to the printer over the bulk OUT endpoint, using USBH_BulkSendData(PRN_Handle->OutPipe) The completion of transfer is detected by polling USBH_LL_GetURBState(), until it returns USBH_URB_DONE. Tsuneo

[fb2]

Posted on August 14, 2015 at 19:23

Hi Tsuneo,

I'm trying to develop the printer class, but I'm facing a strange situation. When I plug my printer (HP LaserJet P1102W) to the USB port, ir reports as class 8 (MSC). I debugged this with a USB viewing utility running on the PC, connected the printer to the PC USB port, and I see that for a moment it detects the printer as MSC, then it gets disconected, and the returns a composite USB device with class 7 (printer).

Do you know something about this, and/or what to do?

Thank you.

Fernando

[Tesla DeLorean]

Posted on August 14, 2015 at 22:33

I have an HP LaserJet P1102W, it presents a MSC to provide drivers/installation for Windows. Perhaps you should check what Windows sends with a protocol analyzer to disconnect/eject the MSC and come back as a printer.

[fb2]

Posted on August 18, 2015 at 14:07

ah ok Clive, that's good information. Thank you very much.

I will investigate with an analyzer tool.

Regards

Fernando

[phenom]

Posted on November 24, 2016 at 14:35

Hi Tsuneo,

I am trying to implement USB printer class.

Instead of STM324xG_EVAL I am using STM32F429I-Discovery. I have tried to convert FWupgrade_Standalone example to Printer class as per the steps mentioned by you.

I am unable to detect printer. I am using HP Laserjet P1606dn printer. But I have also tried to convert FWupgrade_Standalone example to HID class, I am able to detect it successfully.

Can you suggest me why I am unable to detect printer?