Not Finding devices and warnings on Arduino M0

[dvlkv]

In file included from /Users/mrmld/Library/Arduino15/packages/arduino/hardware/samd/1.6.18/cores/arduino/Arduino.h:129:0, from /Users/mrmld/Documents/Arduino/libraries/WebUSB/WebUSB.h:23, from /Users/mrmld/Documents/Arduino/libraries/WebUSB/WebUSB.cpp:26: /Users/mrmld/Documents/Arduino/libraries/WebUSB/WebUSB.cpp: In member function 'virtual int WebUSB::getInterface(uint8_t)': /Users/mrmld/Library/Arduino15/packages/arduino/hardware/samd/1.6.18/cores/arduino/USB/USBCore.h:36:56: warning: narrowing conversion of '(int)((WebUSB)this)->WebUSB::.PluggableUSBModule::pluggedEndpoint' from 'int' to 'uint8_t {aka unsigned char}' inside { } [-Wnarrowing]

define USB_ENDPOINT_OUT(addr) ((addr) | 0x00)

                                                    ^

/Users/mrmld/Library/Arduino15/packages/arduino/hardware/samd/1.6.18/cores/arduino/USB/USBCore.h:276:10: note: in definition of macro 'D_ENDPOINT' { 7, 5, _addr,_attr,_packetSize, _interval } ^ /Users/mrmld/Documents/Arduino/libraries/WebUSB/WebUSB.cpp:150:14: note: in expansion of macro 'USB_ENDPOINT_OUT' D_ENDPOINT(USB_ENDPOINT_OUT(pluggedEndpoint),USB_ENDPOINT_TYPE_BULK,0x40,0), ^ /Users/mrmld/Library/Arduino15/packages/arduino/hardware/samd/1.6.18/cores/arduino/USB/USBCore.h:37:56: warning: narrowing conversion of '((((int)((WebUSB*)this)->WebUSB::.PluggableUSBModule::pluggedEndpoint) + 1) | 128)' from 'int' to 'uint8_t {aka unsigned char}' inside { } [-Wnarrowing]

define USB_ENDPOINT_IN(addr) ((addr) | 0x80)

                                                    ^

/Users/mrmld/Library/Arduino15/packages/arduino/hardware/samd/1.6.18/cores/arduino/USB/USBCore.h:276:10: note: in definition of macro 'D_ENDPOINT' { 7, 5, _addr,_attr,_packetSize, _interval } ^ /Users/mrmld/Documents/Arduino/libraries/WebUSB/WebUSB.cpp:151:14: note: in expansion of macro 'USB_ENDPOINT_IN' D_ENDPOINT(USB_ENDPOINT_IN (pluggedEndpoint+1),USB_ENDPOINT_TYPE_BULK,0x40,0) ^

[jpliew]

@DiE-MaRMeLaDe due to differences in 32bit SAMD21 in M0 and 8bit 32U4 using int, you may be able to cast (uint8_t) in line 150 and 151 of WebUSB.cpp

D_ENDPOINT((uint8_t)USB_ENDPOINT_OUT(pluggedEndpoint),USB_ENDPOINT_TYPE_BULK,0x40,0),
D_ENDPOINT((uint8_t)USB_ENDPOINT_IN (pluggedEndpoint+1),USB_ENDPOINT_TYPE_BULK,0x40,0)

This will remove the -Wnarrowing error. However there should more error that was missed

C:\Users\JP\Documents\Arduino\libraries\WebUSB\WebUSB.cpp:164:42: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]

    if (USB_SendControl(0, &landingPage, 1) < 0)

It will be really hard to get rid of this without major reworking on the M0 USBCore.cpp

uint32_t USBDeviceClass::sendControl(const void* _data, uint32_t len)
{
    const uint8_t *data = reinterpret_cast<const uint8_t *>(_data);
    uint32_t length = len;
    uint32_t sent = 0;
    uint32_t pos = 0;

    if (_dry_run == true)
        return length;

    if (_pack_message == true) {
        memcpy(&_pack_buffer[_pack_size], data, len);
        _pack_size += len;
        return length;
    }

    while (len > 0)
    {
        sent = armSend(EP0, data + pos, len);
        pos += sent;
        len -= sent;
    }

    return length;
}

Above, you can see that in SAMD21's USBCore.cpp the command sendControl only returns unsigned number but in Leonardo sendControl has negative 1 number return that mean something

int USB_SendControl(u8 flags, const void* d, int len)
{
    int sent = len;
    const u8* data = (const u8*)d;
    bool pgm = flags & TRANSFER_PGM;
    while (len--)
    {
        u8 c = pgm ? pgm_read_byte(data++) : *data++;
        if (!SendControl(c))
            return -1;
    }
    return sent;
}

So, either you report a bug at Arduino M0's github or it will be easier and less stress to use another board that is listed here, since M0 is a retired product.

Hope this helps. If you think this answer your questions, please close this issue.