ENC28J60 ist ein einfacher Ethernet-Controller, der als externe Netzwerkkarte für Single-Board-Computer mit GPIO (es gibt sogar einen vorgefertigten Treiber für die Himbeere) und andere Arduine fungieren kann. GPIOs werden auf meinem Laptop nicht angezeigt. Versuchen wir, diesen Fehler zu beheben, und schrauben Sie ENC28J60 mit STM32F103 und einem USB-Kabel daran fest.
Mal sehen, wie Sie das machen können.
Wir brauchen:
ENC28J60
Debug-Board mit STM32 mit USB-Geräteunterstützung (zum Beispiel dieses):
Linux ( Ubuntu 16)
Ethernet ( raspberry pi), wi-fi ( )
STM32F103 , . ENC28J60 ( c ). ENC28J60 STM32F103 SPI1 .
(usb) -> stm32(SPI) -> ENC28J60(Ethernet ) -> raspberry
, user space. tap ( , Ethernet , tun , ip ), ( tap_handler.c). Linux, tap_handler' tap . , , tap , tap_handler', - . , tap_handler tap , /dev/ttyACM0 ( USB Linux). /dev/ttyACM0, tap .
STM32 CubeMX USB CDC (virtual com port). SMT32 Linux /dev/ttyACM0 ( ). , STM32, , STM32.
STM32 . ( CDC_Receive_FS
usbd_cdc_if.c) ENC28J60, , ENC28J60 CDC_Transmit_FS
.
, CDC . , . , ( , wireshark usb). , - - STM32, , .. . .
:
sudo openvpn --mktun --dev tap0
ip :
sudo ifconfig tap0 10.0.0.1/24 up
tap_handler.
/dev/ttyACM0 raw (, .). :
char cdc_name[20]="/dev/ttyACM0";
int tty_fd = open(cdc_name, O_RDWR | O_NOCTTY);
struct termios portSettings;
tcgetattr(tty_fd, &portSettings);
cfmakeraw(&portSettings);
tcsetattr(tty_fd, TCSANOW, &portSettings);
tcflush(tty_fd, TCOFLUSH);
tap_handler tap0:
/* dev tap0*/
int tun_alloc(char *dev, int flags) {
struct ifreq ifr;
int fd, err;
char *clonedev = "/dev/net/tun";
/* /dev/net/tun */
if( (fd = open(clonedev , O_RDWR)) < 0 ) {
perror("Opening /dev/net/tun");
return fd;
}
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = flags;
/* tap0 */
if (*dev) {
strncpy(ifr.ifr_name, dev, IFNAMSIZ);
}
/* */
if( (err = ioctl(fd, TUNSETIFF, (void *)&ifr)) < 0 ) {
perror("ioctl(TUNSETIFF)");
close(fd);
return err;
}
strcpy(dev, ifr.ifr_name);
return fd;
}
main.c :
strcpy(tun_name, "tap0");
int tap_fd = tun_alloc(tun_name, IFF_TAP | IFF_NO_PI);
IFF_TAP (tap). IFF_NO_PI , .
tap0 /dev/ttyACM0. , tap_handler select:
while(1) {
int ret;
fd_set rd_set;
FD_ZERO(&rd_set);
/* tap_fd - tap inteface descriptor */
FD_SET(tap_fd, &rd_set);
/* tty_fd - /dev/ttyACM0 descriptor */
FD_SET(tty_fd, &rd_set);
ret = select(maxfd + 1, &rd_set, NULL, NULL, NULL);
. tap0 tap_handler STM32 ( : - 4 , , 2 - , ) /dev/ttyACM0. , :
if(FD_ISSET(tap_fd, &rd_set)) {
uint16_t nread = cread(tap_fd, buffer, BUFSIZE);
uint8_t buf[6];
*(uint32_t *)buf = PACKET_START_SIGN;
*(uint16_t *)(buf + 4) = nread;
cwrite(tty_fd,(char *)buf,6);
cwrite(tty_fd, buffer, nread);
delay_micro(delay_m);
}
/dev/ttyACM0, ( 4 ), , . tap :
if(FD_ISSET(tty_fd, &rd_set)) {
uint32_t sign;
/* */
int nread = read_n(tty_fd, (char *)&sign, sizeof(sign));
/* , */
if(nread == 0) {
break;
}
/* , 4 */
if(sign != PACKET_START_SIGN){
continue;
}
/* */
nread = read_n(tty_fd, (char *)&plength, 2);
if(nread == 0) {
break;
}
if (nread != 2){
continue;
}
/* , */
if(flag){
flag = 0;
nread = cread(tty_fd, buffer, sizeof(buffer));
if(nread != 6){
continue;
}
}
/* , */
if(plength > BUFSIZE){
break;
}
/* (plength ) tap interface*/
nread = read_n(tty_fd, buffer, plength);
if (nread != 0){
cwrite(tap_fd, buffer, nread);
delay_micro(delay_m);
}
}
STM32
USB CDC CubeMX HAL SPI1 .
callback' CDC_Receive_FS
( usbd_cdc_if.c), USB. , , ENC28J60. :
/* USB_POINTERS_ARRAY_SIZE - array_pos */
/* MAX_FRAMELEN - */
/* USB_BUFSIZE - */
extern uint8_t usb_buf[]; /* */
extern uint32_t pos_int; /* */
extern uint32_t array_pos[]; /* , */
extern uint32_t p_a; /* array_pos CDC_Receive_FS*/
extern uint32_t pl_a;/* array_pos */
/* USB_POINTERS_ARRAY_SIZE - array_pos */
/* MAX_FRAMELEN - */
/* USB_BUFSIZE - */
static int8_t CDC_Receive_FS(uint8_t* Buf, uint32_t *Len)
{
int8_t memok = 1;
/* , */
if( pl_a !=0 && p_a !=0){
int32_t mem_lag = array_pos[(p_a - 1) % USB_POINTERS_ARRAY_SIZE] - array_pos[(pl_a - 1) % USB_POINTERS_ARRAY_SIZE];
if(mem_lag > USB_BUFSIZE - MAX_FRAMELEN)
memok = 0;
}
/* ,
(array_pos) */
if(*Len < USB_BUFSIZE && *Len != 0 && memok){
uint16_t offset = pos_int % USB_BUFSIZE;
uint16_t new_pos = offset + *Len;
uint8_t split = 0;
if (new_pos > USB_BUFSIZE){
split = 1;
}
if(split){
int len1 = USB_BUFSIZE - offset;
int len2 = *Len - len1;
memcpy(usb_buf + offset, Buf, len1);
memcpy(usb_buf, Buf + len1, len2);
}
else
memcpy(usb_buf + offset, Buf, *Len);
pos_int += *Len;
array_pos[p_a % USB_POINTERS_ARRAY_SIZE] = pos_int;
p_a++;
}
USBD_CDC_SetRxBuffer(&hUsbDeviceFS, &Buf[0]);
USBD_CDC_ReceivePacket(&hUsbDeviceFS);
return (USBD_OK);
}
(main.c) ENC28J60:
if(pl_a < p_a){
uint32_t prev = 0;
if(pl_a > 0)
prev = array_pos[(pl_a - 1) % USB_POINTERS_ARRAY_SIZE];
/* ( ), CDC_Receive_FS */
int32_t n = array_pos[pl_a % USB_POINTERS_ARRAY_SIZE] - prev;//usb frame size
/* */
uint8_t *from = usb_buf + prev % USB_BUFSIZE;
/* */
uint8_t right_n = 1;
if (n < 0 || n > MAX_FRAMELEN){
right_n = 0;
}
/* . 6 ( 4 2 ) */
if((packet_len == 0) && packet_start && (n > 5) && right_n){
/* . */
uint32_t sign = read32(from,usb_buf);
/* 4 */
uint8_t *next = next_usb_ptr(from,usb_buf,4);
/* */
packet_size = read16(next,usb_buf);// 2 bytes after sign is packet length
/* */
if (packet_size > MAX_FRAMELEN || sign != PACKET_START_SIGN){
packet_size = 0;
}
else{
/* */
next = next_usb_ptr(from,usb_buf,6);
copy_buf(packet_buf, next, usb_buf, n - 6);
packet_len = n - 6;
packet_next_ptr = packet_buf + packet_len;
packet_start = 0;
}
}
/* */
else if(packet_len < packet_size && right_n){
/* */
copy_buf(packet_next_ptr, from, usb_buf, n);
packet_len += n;
packet_next_ptr = packet_buf + packet_len;
}
/* */
else if (packet_len > packet_size){
packet_len = 0;
packet_start = 1;
}
/* enc28j60 */
if(packet_len == packet_size && packet_size > 0){
enc28j60_packetSend(packet_buf, packet_size);
packet_len = 0;
packet_start = 1;
}
pl_a++;
}
ENC28J60 USB :
len = enc28j60_packetReceive(net_buf,sizeof(net_buf));
if (len > 0) {
*((uint16_t*)(sign_buf + 4)) = len;
while(CDC_Transmit_FS(sign_buf, sizeof(sign_buf)) == USBD_BUSY_CDC_TRANSMIT);
while(CDC_Transmit_FS(net_buf, len) == USBD_BUSY_CDC_TRANSMIT);
HAL_GPIO_TogglePin(GPIOC, GPIO_PIN_13);
}
CDC_Transmit_FS
, while. CDC_Transmit_FS
USBD_BUSY_CDC_TRANSMIT
USBD_BUSY
. :
if (hcdc->TxState != 0){
return USBD_BUSY_CDC_TRANSMIT;
}
ENC28J60 enc28j60_ini
, (promiscuous mode):
enc28j60_writeRegByte(ERXFCON,0);
Raspberry
eth0 ip . ping
sudo ifconfig eth0 up 10.0.0.2/24 ping 10.0.0.2
tcpdump:
sudo tcpdump -i eth0
STM32 , ENC28J60 raspberry. STM32 , arp / icmp ( ping). , /dev/ttyACM0:
ls /dev/ttyACM*
tap_handler:
gcc tap_handler.c -o tap_handler ./tap_handler
tap_handler - raspberry, tap0, , STM32, raspberry , .
.
raspberry ssh wi-fi , , default gateway. , raspberry :
sudo route del default gateway 192.168.1.1 sudo route add default gateway 10.0.0.2
DNS ( /etc/resolv.conf nameserver, , 8.8.8.8).
Raspberry
eth0 wlan0 NAT:
echo 1 | sudo tee -a /proc/sys/net/ipv4/ip_forward
sudo iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE
. , ( 0.5 /).
Sie müssen sich nicht um die Himbeere kümmern, sondern müssen das Netzwerkkabel vom Router direkt mit dem ENC28J60 verbinden (Sie müssen das WLAN auf Ihrem Computer ausschalten und die richtige Tap0-Adresse einstellen). Aber es ist einfacher mit Himbeeren zu testen, Sie können alles sehen, was in tcpdump passiert.
Warum das alles
Die Verwendung eines solchen Bundles im Leben ist wahrscheinlich nicht sehr praktisch (insbesondere wenn preiswerte USB-Ethernet-Adapter im Angebot sind), aber es war sehr interessant, es herzustellen. Vielen Dank für Ihre Aufmerksamkeit. Code- Link (Projekt in Atollic TrueStudio).