Prolific PL2303 driver

Does anybody have a driver for a USB to serial adaptor based upon the Prolific PL2303?

Does anybody have a driver for a USB to serial adaptor based upon the Prolific PL2303?

Windows drivers I presume?
In which case the answer is yes, but IIRC the only copy is on the server at work¹ (it’s what I use for the console connection onto the network kit (along with the Female gender change lump cos the serial end is male)

This stuff?

==========
PL2303 Driver Setup Installer, Prolific Edition
Setup Installer Revision Note History
==========

System Requirement:
. USB 1.1/2.0/3.0 Host Controller
. Device using PL2303HXA/XA/HXD/EA/RA/SA/TA/TB version chips
. Supports the following Windows OS Family:
- Windows 2000 SP4
- Windows XP SP2 and above (32 & 64 bit)
- Windows Server 2003 (32 & 64 bit)
- Windows Vista (32 & 64 bit)
- Windows 7 (32 & 64 bit)
- Windows Server 2008 / 2008 R2 (32 & 64 bit)
- Windows 8 (32 & 64 bit)
- Windows 8.1 (32 & 64 bit)
- Windows Server 2012
NOTE:
– Windows 8 and above are NOT supported in PL2303HXA/XA chip versions.
– Windows 8/8.1 are supported only in following chip versions:
– PL2303HXD (HX Rev D)
– PL2303EA (HXD with ESD protection)
– PL2303RA (HXD with Built-in transceiver)
– PL2303SA (HXD SOP8 package)
– PL2303TA (PL2303HXA/XA replacement)
– PL2303TB (12 GPIO)
– Download latest PL2303 CheckChipVersion tool program to check chip version in Windows 7.
– Windows 98 and ME driver support are discontinued.

Supported device ID and product strings:
. VID_067B&PID_2303 for “Prolific USB-to-Serial Comm Port” (PL2303HXA/XA/HXD/EA/RA/SA/TA chips)
. VID_067B&PID_2304 for “Prolific USB-to-Serial Comm Port” (PL2303TB chip)

Windows drivers I presume?

That would surely be a topic for Aldershot?

I’m looking for a PL2303 driver for RISC OS.

I’m looking for a PL2303 driver for RISC OS.

Ah, just didn’t associate RO and hardware drivers

I know only one for the FTDI chipset.

I’m looking for a PL2303 driver for RISC OS.

The source at:
http://lxr.free-electrons.com/source/drivers/usb/serial/pl2303.c
http://lxr.free-electrons.com/source/drivers/usb/serial/pl2303.h

Might vaguely interest you, or not

Thanks Steve.

I had a look at Thomas’ module, the pl2303 source you pointed to, and the associated FTDI code. The serial devices seem to be pretty similar, to the extent where I wonder if it would be possible to bodge Prolific support into the FTDI module.

But, alas, I don’t feel like dealing with low level device drivers. I can’t say “pffft, I’ll just write something in VB” because my Pi eats 7W from the mains. The PC? About twenty times that. :-/ Hardly something I’d feel happy leaving always-on.

So, I wussed out…

Edit: picked up this one as well as it looks like it might support more pins and I think the device I want to use does something weird like holding some of the flow control lines (DTR and RTS, I think) at fixed state to define the serial high and low levels.

I spent a rather frustrating time a couple or so years back trying to get a PL2303 to work. I developed a strong dislike of the device.

However, this thread piqued my curiosity, so I went back to have another look. I had written a short BASIC experimental app. Its calls to start the PL2303 up were clearly inspired by the Linux driver. When I took out the other calls that I had added (which were almost certainly derived by reverse engineering what the Windows driver did), I was able to get basic transmission working at two baud rates.

The limitation is that you can only run it once – subsequent runs stop it working until it’s unplugged and replugged. However, that wouldn’t be a problem in a module driver that opened it only once.

So I’ve started a module driver in C.

It occurred to me that serial devices are most commonly accessed in RISC OS via blockdrivers, and that it might be possible to have one USB serial blockdriver that would interface to any USB serial device driver module if we could standardise the module API. To make it easy to understand, it seems to me that the module’s API should follow that blockdriver’s API as closely as possible. Then when the blockdriver is initialised, it has to be given the SWI base of the particular module that it will call.

Thoughts, anyone?

Dunno how it would cope with multiple USB serial dongles of the same type, but I guess that’s a much rarer requirement.

If I remember correctly, the sp_dual blockdriver used a register to select which port was to be used, and the same blockdriver did both ports. The blockdriver spec will need to be updated to cater for events that were impossible in the late eighties – just as I am doing with the MIDI driver – namely the ability to add and remove devices on the fly, plus the wrinkle that a device when re inserted may or may not be the same device (if you have two serial leads, can you tell them apart in software when there’s no dedicated port?) but it’ll certainly have a different USB ID. Fun! :-)

I think for now, just concentrate on getting one to work. Multiples can be a luxury for another time.

I’m looking forward to trying this, though I can’t speak for the provenance of the cable, if it is real or a better quality clone…

By the way, how do you read from the control port? I have wondered if the MIDI dongle has a way of flagging that it’s buffer is full, but I haven’t had any success reading the control port. I was thinking that if I could get that working, to hammer it with data (not difficult :-/ ) and keep reading the control port to see if anything changes between slow data (under MIDI speed) and faster data (saturates and loses bytes).
Unfortunately although the MIDI spec is defined (it isn’t the mess that USB serial is), it says nothing about control ports or flow control, and, well, passing a SysEx through the cheap interfaces is an exercise in self flagellation…

I have written a generic DeviceFS driver which handles CP210x and CH340 usb serial devices at the moment it works very well – 960k with handshaking on the cp210x – but I couldn’t find a way around handshaking causing the machine to lock up when you did something like echo test { > serialusb#rts: } and you don’t get the clear to send signal – a problem standard serial: devices also have. Devices are allocated serialusb names in the order they are seen – a device with multiple ports are given multiple names so are seen as different devices. New devices can be added in a similar way to EtherUSB. It works the same as the standard “serial:” devices.

I don’t have a devicefs/module allocation at the moment so haven’t released it.

Sent

it says nothing about control ports or flow control

I wouldn’t have thought Midi would have flow control because the data is time dependent. I can’t see that it would have much to control either isn’t the baud rate and word format fixed?

Thanks. Sadly it doesn’t recognise my device – a Prolific PL2303. It seems, by looking in the module, that it’s main support is for the Silicon Labs CP210x (as mentioned).
It is quite the same that one of the simplest and most ubiquitous interfaces of the eighties is such a <beep>ing mess in USB.

If it is any use, my device is Vendor ID 067B and Product ID 2303, Device ID 0300. Address 8, config 1, class/subclass/protocol all zero. There is one interface with three endpoints.

1. appears to be data to the computer, a 10 byte buffer, and I’m not sure what the blue PacMan icon in USBInfo means, but it says 1ms beside it.
2. is data from the computer. 64 byte buffer.
3. is data to the computer. 64 byte buffer.

Or, from the command line:

Interface 0.0 class 255.0:0 ’’
1 IN Interrupt 10 bytes 1 frames
2 OUT Bulk 64 bytes 0 frames
3 IN Bulk 64 bytes 0 frames

If this in any way resembles the CH340 or CP210x, I’d be willing to give it a try if you can tweak the device recognition? Probably won’t work (as it is a different device), but hey, worth a try, no? ;-)

Update: the clone, that I know is a clone, provides exactly the same information.

Yes I knew the PL2303 wouldn’t work. Unlike USB Audio USB serial doesn’t have a standard interface so a driver has to be written for each device – it’s similar to USB Ethernet in that respect. As luck would have it I’ve just tried an old pic programmer I have and that is the same usb device as yours so I may be able to write a backend for that. I remember I had trouble with the device on windows. I had to use an old driver to get it to work, which windows kept updating. I think prolific is in a piracy battle and keep changing their chips so the drivers don’t work with pirated chips.

The PL2303 that I have is the one commonly sold for connecting PC’s (that have USB serial drivers) to the Pi. It has the flying leads for the Pi connection.
What went through my mind on this subject was to gleen some info from wireshark and have TX and RX connected. I think some linux terminals support that connection. A bit like the Acorn terminal pipe A-B setting. It would at least simplify the use down to one machine for gathering data.
On the subject of wireless internet, would it be more feasible to get a driver talking to a mobile phone com port) This might be able to use existing modem PPP suport on the network side. Linux has a common device driver for usb connected phones, well my Alcatel, at least.
Like other linux drivers, it will be mangled with Linux style sessions making it not traslateable, which is why I mentioned wireshark as an aid for the PL2303 also. Good to hear the three experts have been/are on the job though.
I bought a Garmin GPSmap 60CSx recently looks like it might be the end of real serial ports on that range in favour of USB also.

I use snoopy on a PC. It turned out for the PL2303 device I have the only commands that worked were enabling the device and changing the baud rate. The Snoopy output showed commands to change word format but these didn’t actually do anything when I checked with an oscilloscope.

On the subject of wireless internet, would it be more feasible to get a driver talking to a mobile phone com port) This might be able to use existing modem PPP suport on the network side.

This is exactly what Thomas Milius’ ComCentre does. Works fine with many USB “SurfSticks”.

http://www.thomas-milius.privat.t-online.de/Download/Freeware/COMCentre.zip

I remember I had trouble with the device on windows. I had to use an old driver to get it to work, which windows kept updating.

Yup. I rolled back my driver and refused any subsequent updates. Thankfully they haven’t pulled an FTDI on us yet…

The Snoopy output showed commands to change word format but these didn’t actually do anything when I checked with an oscilloscope.

Might be worth looking at the Linux driver that Steve linked above to see if the commands the driver tries to send matches up with what you are seeing in Snoopy?

We’re getting closer. I have a SerialUSB device now, but…

Using 'SerialUSB#noblock;sleep;nohandshake;baud=115200;data=8;stop=1;noparity:'

Cannot find a valid endpoint(23)
*

That’s with the known-clone¹ looped back to the Pi’s UART; and also with the better built one (so unknown if it is real or a clone).

¹ It claims to be a Prolific PL2303HX, but there’s a big Xtal between two pins that are marked “reserved” on the PL2303 datasheet. That ought to be a giveaway… ;-)

I you run usbdescriptors with the device plugged in. Then search for 2303 you should find something like the output below. If you post your version I’ll see what I can do.

=============================================
 Device USB12
=============================================
:  0 :  2 : total size of ServiceCall block : 91
:  2 :  2 : offset to descriptor list       : 0x20
:  4 : 20 : name                            : USB12
: 24 :  1 : bus number                      : 1
: 25 :  1 : device address                  : 7
: 26 :  1 : host address                    : 2
: 27 :  1 : host port                       : 6
: 28 :  1 : speed                           : 2 full speed
---------------------------------------------

 Standard Device Descriptor
+----+----+---------------------------+----------+------------+
:Off :Sz  :Name                       :Value hex :Value dec   :
+----+----+---------------------------+----------+------------+
:  0 :  1 : bLength                   :       12 :         18 : 
:  1 :  1 : bDescriptorType           :        1 :          1 : 
:  2 :  2 : bcdUSB                    :      110 :        272 : 
:  4 :  1 : bDeviceClass              :        0 :          0 : 
:  5 :  1 : bDeviceSubClass           :        0 :          0 : 
:  6 :  1 : bDeviceProtocol           :        0 :          0 : 
:  7 :  1 : bMaxPacketSize            :       40 :         64 : 
:  8 :  2 : idVendor                  :      67b :       1659 : 
: 10 :  2 : idProduct                 :     2303 :       8963 : 
: 12 :  2 : bcdDevice                 :      300 :        768 : 
: 14 :  1 : iManufacturer             :        1 :          1 : 'Prolific Technology Inc.'
: 15 :  1 : iProduct                  :        2 :          2 : 'USB-Serial Controller'
: 16 :  1 : iSerialNumber             :        0 :          0 : ''
: 17 :  1 : bNumConfigurations        :        1 :          1 : 
+----+----+---------------------------+----------+------------+

 Standard Configuration Descriptor
+----+----+---------------------------+----------+------------+
:Off :Sz  :Name                       :Value hex :Value dec   :
+----+----+---------------------------+----------+------------+
:  0 :  1 : bLength                   :        9 :          9 : 
:  1 :  1 : bDescriptorType           :        2 :          2 : 
:  2 :  2 : wTotalLength              :       27 :         39 : 
:  4 :  1 : bNumInterfaces            :        1 :          1 : 
:  5 :  1 : bConfigurationValue       :        1 :          1 : 
:  6 :  1 : iConfiguration            :        0 :          0 : ''
:  7 :  1 : bmAttributes              :       80 :        128 : (bit7) USB 1.0 bus powered
(bit6) Bus powered, (bit5) No remote wakeup
:  8 :  1 : bMaxPower                 :       32 :         50 : 100mA
+----+----+---------------------------+----------+------------+

     Standard Interface Descriptor
    +----+----+---------------------------+----------+------------+
    :Off :Sz  :Name                       :Value hex :Value dec   :
    +----+----+---------------------------+----------+------------+
    :  0 :  1 : bLength                   :        9 :          9 : 
    :  1 :  1 : bDescriptorType           :        4 :          4 : 
    :  2 :  1 : bInterfaceNumber          :        0 :          0 : 
    :  3 :  1 : bAlternateSetting         :        0 :          0 : 
    :  4 :  1 : bNumEndpoints             :        3 :          3 : 
    :  5 :  1 : bInterfaceClass           :       ff :        255 : Vendor Specific
    :  6 :  1 : bInterfaceSubClass        :        0 :          0 : 
    :  7 :  1 : bInterfaceProtocol        :        0 :          0 : 
    :  8 :  1 : iInterface                :        0 :          0 : ''
    +----+----+---------------------------+----------+------------+

         Standard Endpoint Descriptor
        +----+----+---------------------------+----------+------------+
        :Off :Sz  :Name                       :Value hex :Value dec   :
        +----+----+---------------------------+----------+------------+
        :  0 :  1 : bLength                   :        7 :          7 : 
        :  1 :  1 : bDescriptorType           :        5 :          5 : 
        :  2 :  1 : bEndpointAddress          :       81 :        129 : Endpoint 1 - IN
        :  3 :  1 : bmAttributes              :        3 :          3 : Interrupt
        :  4 :  2 : wMaxPacketSize            :        a :         10 : 1 x 10 byte max packets
        :  6 :  1 : bInterval                 :        1 :          1 : 
        +----+----+---------------------------+----------+------------+

         Standard Endpoint Descriptor
        +----+----+---------------------------+----------+------------+
        :Off :Sz  :Name                       :Value hex :Value dec   :
        +----+----+---------------------------+----------+------------+
        :  0 :  1 : bLength                   :        7 :          7 : 
        :  1 :  1 : bDescriptorType           :        5 :          5 : 
        :  2 :  1 : bEndpointAddress          :        2 :          2 : Endpoint 2 - OUT
        :  3 :  1 : bmAttributes              :        2 :          2 : Bulk
        :  4 :  2 : wMaxPacketSize            :       40 :         64 : 1 x 64 byte max packets
        :  6 :  1 : bInterval                 :        0 :          0 : 
        +----+----+---------------------------+----------+------------+

         Standard Endpoint Descriptor
        +----+----+---------------------------+----------+------------+
        :Off :Sz  :Name                       :Value hex :Value dec   :
        +----+----+---------------------------+----------+------------+
        :  0 :  1 : bLength                   :        7 :          7 : 
        :  1 :  1 : bDescriptorType           :        5 :          5 : 
        :  2 :  1 : bEndpointAddress          :       83 :        131 : Endpoint 3 - IN
        :  3 :  1 : bmAttributes              :        2 :          2 : Bulk
        :  4 :  2 : wMaxPacketSize            :       40 :         64 : 1 x 64 byte max packets
        :  6 :  1 : bInterval                 :        0 :          0 : 
        +----+----+---------------------------+----------+------------+

Thanks. I’ll run that on both of the devices and post the results when I get back home.

I’m waiting for a burger…

Might be worth looking at the Linux driver that Steve linked above to see if the commands the driver tries to send matches up with what you are seeing in Snoopy?

That’s stuff pointed at by the prolific web site among the support category.
There are also some test apps and source actually on the prolific site. Android might be half useful

The better quality serial lead (the one I specifically want to use):

=============================================
 Device USB19
=============================================
:  0 :  2 : total size of ServiceCall block : 91
:  2 :  2 : offset to descriptor list       : 0x20
:  4 : 20 : name                            : USB19
: 24 :  1 : bus number                      : 1
: 25 :  1 : device address                  : 5
: 26 :  1 : host address                    : 3
: 27 :  1 : host port                       : 2
: 28 :  1 : speed                           : 2 full speed
---------------------------------------------

 Standard Device Descriptor
+----+----+---------------------------+----------+------------+
:Off :Sz  :Name                       :Value hex :Value dec   :
+----+----+---------------------------+----------+------------+
:  0 :  1 : bLength                   :       12 :         18 : 
:  1 :  1 : bDescriptorType           :        1 :          1 : 
:  2 :  2 : bcdUSB                    :      110 :        272 : 
:  4 :  1 : bDeviceClass              :        0 :          0 : 
:  5 :  1 : bDeviceSubClass           :        0 :          0 : 
:  6 :  1 : bDeviceProtocol           :        0 :          0 : 
:  7 :  1 : bMaxPacketSize            :       40 :         64 : 
:  8 :  2 : idVendor                  :      67b :       1659 : 
: 10 :  2 : idProduct                 :     2303 :       8963 : 
: 12 :  2 : bcdDevice                 :      300 :        768 : 
: 14 :  1 : iManufacturer             :        1 :          1 : 'Prolific Technology Inc.'
: 15 :  1 : iProduct                  :        2 :          2 : 'USB-Serial Controller'
: 16 :  1 : iSerialNumber             :        0 :          0 : ''
: 17 :  1 : bNumConfigurations        :        1 :          1 : 
+----+----+---------------------------+----------+------------+

 Standard Configuration Descriptor
+----+----+---------------------------+----------+------------+
:Off :Sz  :Name                       :Value hex :Value dec   :
+----+----+---------------------------+----------+------------+
:  0 :  1 : bLength                   :        9 :          9 : 
:  1 :  1 : bDescriptorType           :        2 :          2 : 
:  2 :  2 : wTotalLength              :       27 :         39 : 
:  4 :  1 : bNumInterfaces            :        1 :          1 : 
:  5 :  1 : bConfigurationValue       :        1 :          1 : 
:  6 :  1 : iConfiguration            :        0 :          0 : ''
:  7 :  1 : bmAttributes              :       80 :        128 : (bit7) USB 1.0 bus powered (bit6) Bus powered, (bit5) No remote wakeup
:  8 :  1 : bMaxPower                 :       32 :         50 : 100mA
+----+----+---------------------------+----------+------------+

     Standard Interface Descriptor
    +----+----+---------------------------+----------+------------+
    :Off :Sz  :Name                       :Value hex :Value dec   :
    +----+----+---------------------------+----------+------------+
    :  0 :  1 : bLength                   :        9 :          9 : 
    :  1 :  1 : bDescriptorType           :        4 :          4 : 
    :  2 :  1 : bInterfaceNumber          :        0 :          0 : 
    :  3 :  1 : bAlternateSetting         :        0 :          0 : 
    :  4 :  1 : bNumEndpoints             :        3 :          3 : 
    :  5 :  1 : bInterfaceClass           :       ff :        255 : Vendor Specific
    :  6 :  1 : bInterfaceSubClass        :        0 :          0 : 
    :  7 :  1 : bInterfaceProtocol        :        0 :          0 : 
    :  8 :  1 : iInterface                :        0 :          0 : ''
    +----+----+---------------------------+----------+------------+

         Standard Endpoint Descriptor
        +----+----+---------------------------+----------+------------+
        :Off :Sz  :Name                       :Value hex :Value dec   :
        +----+----+---------------------------+----------+------------+
        :  0 :  1 : bLength                   :        7 :          7 : 
        :  1 :  1 : bDescriptorType           :        5 :          5 : 
        :  2 :  1 : bEndpointAddress          :       81 :        129 : Endpoint 1 - IN
        :  3 :  1 : bmAttributes              :        3 :          3 : Interrupt
        :  4 :  2 : wMaxPacketSize            :        a :         10 : 1 x 10 byte max packets
        :  6 :  1 : bInterval                 :        1 :          1 : 
        +----+----+---------------------------+----------+------------+

         Standard Endpoint Descriptor
        +----+----+---------------------------+----------+------------+
        :Off :Sz  :Name                       :Value hex :Value dec   :
        +----+----+---------------------------+----------+------------+
        :  0 :  1 : bLength                   :        7 :          7 : 
        :  1 :  1 : bDescriptorType           :        5 :          5 : 
        :  2 :  1 : bEndpointAddress          :        2 :          2 : Endpoint 2 - OUT
        :  3 :  1 : bmAttributes              :        2 :          2 : Bulk
        :  4 :  2 : wMaxPacketSize            :       40 :         64 : 1 x 64 byte max packets
        :  6 :  1 : bInterval                 :        0 :          0 : 
        +----+----+---------------------------+----------+------------+

         Standard Endpoint Descriptor
        +----+----+---------------------------+----------+------------+
        :Off :Sz  :Name                       :Value hex :Value dec   :
        +----+----+---------------------------+----------+------------+
        :  0 :  1 : bLength                   :        7 :          7 : 
        :  1 :  1 : bDescriptorType           :        5 :          5 : 
        :  2 :  1 : bEndpointAddress          :       83 :        131 : Endpoint 3 - IN
        :  3 :  1 : bmAttributes              :        2 :          2 : Bulk
        :  4 :  2 : wMaxPacketSize            :       40 :         64 : 1 x 64 byte max packets
        :  6 :  1 : bInterval                 :        0 :          0 : 
        +----+----+---------------------------+----------+------------+

Just checked the clone device. The response is the same.

BTW, what’s Snoopy? Will it run on XP?

The descriptors look identical so it’s odd that is doesn’t find the endpoint. Are you using an old os version? An old USB driver may be the problem.

BTW, what’s Snoopy? Will it run on XP?

SnoopyPro. Its from 2002 so I’d expect it to work on XP.

Are you using an old os version? An old USB driver may be the problem.

Yup. It works on the latest version of RISC OS. I wasn’t aware that my one was that out of date.

Dammit. I’m going to have to unpack and mod my own… such a pain… ;-)