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anemo
Joined: 24 Apr 2016
Posts: 9
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| USB HID via usb type C |
 Posted: Tue Jan 31, 2017 2:39 pm |
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Hello!
I'm trying to connect an PIC18F4550 to a Macbook via USB type C. I'm using example code and self-powered USB circuit (100k between Vcc and USB Vcc, 4k7 between USB Vcc and USB Gnd, etc.).
When I connect PIC to a normal PC (Win10 64bit), it works successfully (the pic is recognised as HID device), but when i connect to a Macbook (Win10 64bit using Boot Camp), i get an error: device descriptor request failed.
The Macbook has only one USB-C connector.
Does anyone know what the problem is? Can HID work via USB-C or on Macbook? Or my sample code is wrong?
I'm using MPLAB X IDE v3.51 and CCS v5.011. The PICKIT2 works.
Thank you!
| Code: | #include <18F4550.h>
#fuses HSPLL,NOWDT,NOPROTECT,NOLVP,NODEBUG,USBDIV,PLL5,CPUDIV1,VREGEN
#use delay(clock=48000000)
#define PIN_USB_SENSE PIN_C0
#define USB_CONFIG_HID_TX_SIZE 2
#define USB_CONFIG_HID_RX_SIZE 2
#include <pic18_usb.h>
#include <usb_desc_hid.h> //USB Configuration and Device descriptors for this UBS device
#include <usb.c> //handles usb setup tokens and get descriptor reports
void main(void)
{
int8 out_data[USB_CONFIG_HID_TX_SIZE];
int8 in_data[USB_CONFIG_HID_RX_SIZE];
int8 send_timer=0;
int8 send_timer2=0;
usb_init_cs();
while (TRUE)
{
usb_task();
usb_attached();
usb_enumerated();
delay_ms(1);
send_timer++;
if (send_timer == 500)
{
output_toggle(PIN_D1);
send_timer = 0;
}
}
} |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19547
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| Posted: Tue Jan 31, 2017 2:48 pm |
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Stick a USB-2 bub between the devices.
USB-C just like USB-3, requires such fast switching capabilities from the drivers, that even when it is switched 'down' to USB-2 mode, it can cause signalling problems if the bus impedance is not well matched.
Your code _must_ include usb_task in the loop. It is this that handles the 'housekeeping' for the USB. It only needs to be called at intervals, but it must be called. In this case it might well start working if you do this, since part of the negotiations carried out by the USB-C device will involve it disconnecting, and re-enumerating. Without usb_task being called again, this won't happen. |
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temtronic
Joined: 01 Jul 2010
Posts: 9245
Location: Greensville,Ontario
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| Posted: Tue Jan 31, 2017 2:54 pm |
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Since your PIC with USB code works fine connected to a PC,I'd say the MAC is at fault. Kinda 'old school' logic...
Since I never heard of USB-C I did a quick google. yeesh...the USB-C cable has a chip INSIDE it according to one source.....so who KNOWs what's going on...let alone 'compatibility'.
Last MAC I worked on ,was the originals, did memory upgrades for 10% of what Apple was charging....
Now you're trying to get a MAC to 'emulate' Windows...that should be 'fun'...but IF you had USBView, I'd run it to see what 'USB' devices the MAC thinks you have.
Jay |
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anemo
Joined: 24 Apr 2016
Posts: 9
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| Posted: Tue Jan 31, 2017 3:08 pm |
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| Ttelmah wrote: | | Stick a USB-2 bub between the devices. |
It means hub? i hope, beacuse I've just tried with passive usb hub, but it doesn't work, unfortunately.
Thank you. |
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anemo
Joined: 24 Apr 2016
Posts: 9
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| Posted: Tue Jan 31, 2017 3:17 pm |
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| temtronic wrote: | Since your PIC with USB code works fine connected to a PC,I'd say the MAC is at fault. Kinda 'old school' logic...
Since I never heard of USB-C I did a quik google. yeesh...the USB-C cable has a chip INSIDE it according to one source.....so who KNOWs what's going on...let alone 'compatibility'.
Last MAC I worked on ,was the originals, did memory upgrades for 10% of what Apple was charging....
Now you're trying to get a MAC to 'emulate' Windows...that should be 'fun'...but IF you had USBView, I'd run it to see what 'USB' devices the MAC thinks you have.
Jay |
It sounds like not good. Actually it's not emulating. OS X has a basic app to install Windows... it creates a second partition on your ssd for windows.
Thanks. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19547
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| Posted: Wed Feb 01, 2017 3:19 am |
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Add the usb_task to the loop.
This is _required_.
Basically 'usb_task' does two jobs.
On a system not using interrupts it handles everything, and must be called very frequently (max about 10mSec between calls). On a standard system using interrupts to handle the data transactions it must still be called perhaps a couple of times a second to do the USB 'housekeeping'.
Now on USB-C hosts, the host actually disconnects and re-connects during the initialisation, as it 'works out' what capabilities the device has. USB_task must be called to handle this. Since you only call it once, I'd expect it not to work.
I'm typing this on a Retina Imac, with USB-C ports, and currently debugging a PIC system, using an ICD, two USB connections, and virtual W-XP, W7 & W10, to test the code. All run fine. The PIC is happily handled by all four OS's (the Mac included).
One other thing though, is a comment I made a few days ago. When connecting to these higher speed busses, it does show any impedance problems more than on standard USB busses. Systems that did work fine sometimes give problems and may need small 'series' resistors in the two USB lines, to reduce transmission line problems. However this shouldn't apply if going via a hub. |
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anemo
Joined: 24 Apr 2016
Posts: 9
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| Posted: Wed Feb 01, 2017 10:58 am |
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I call usb_task() inside while(true) loop with 1 ms interval, as you can see at embedded code, or you thought something else?
Thanks. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19547
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| Posted: Wed Feb 01, 2017 11:24 am |
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OK.
I was not reading this as being the loop.
There are several things wrong then.
usb_enumerated is a routine you call to _test_ if the system is enumerated. The same applies for usb_attached.
You should be testing usb_attached, and if it is attached, then test if it is enumerated. Only if it is both attached and enumerated, then you loop calling task _while_ these remain true.
Look at the examples, and re-write your code like them. |
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anemo
Joined: 24 Apr 2016
Posts: 9
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| Posted: Wed Feb 01, 2017 12:36 pm |
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I did, but nothing changed (still "device descriptor request failed"). I tried with and without hub also. Remark: i have to use apple usb-C/usb-A adapter between mac and pic, because not have special cable.. it may be causing something.
This is the code i've just used. (According to example, the usb_task() is the first, then attached, enum..)
| Code: | #include <18F4550.h>
#fuses HSPLL,NOWDT,NOPROTECT,NOLVP,NODEBUG,USBDIV,PLL5,CPUDIV1,VREGEN
#use delay(clock=48000000)
#define PIN_USB_SENSE PIN_C0
#define USB_CONFIG_HID_TX_SIZE 2
#define USB_CONFIG_HID_RX_SIZE 2
#include <pic18_usb.h>
#include <usb_desc_hid.h> //USB Configuration and Device descriptors for this UBS device
#include <usb.c> //handles usb setup tokens and get descriptor reports
void main(void)
{
delay_ms(1000);
int8 out_data[USB_CONFIG_HID_TX_SIZE];
int8 in_data[USB_CONFIG_HID_RX_SIZE];
int8 send_timer=0;
usb_init_cs();
while (TRUE)
{
usb_task();
if (usb_attached())
{
if (usb_enumerated())
{
send_timer++;
if (send_timer == 500)
{
output_toggle(PIN_D1);
send_timer = 0;
}
}
}
delay_ms(1);
}
} |
[/code] |
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anemo
Joined: 24 Apr 2016
Posts: 9
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| Posted: Fri Feb 03, 2017 2:50 am |
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| Problem solved. The capacitor between gnd and VUSB pin was wrong, i fixed it and now Mac can recognise pic. Thank you. |
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