Hi, guys! Thank you for watching this.
I’m having difficulties with my BBB on CAN communication like for months…
I’d be really pleased if you could give me just a little help!
I’m working on CAN protocol between BBB and another CAN device.
The another device is confirmed to be working alright with CAN.
I’m using my BBB with Cloud9 platform on windows laptop,
and on the another device, it’s using CAN0.
I have set the ‘config-pin’ on BBB like below using CAN1, and I tried ‘cansend’ utility.
The bitratre value on the another device is also set to be equal.
config-pin p9.24 can
config-pin p9.26 can
ip link set can1 up type can bitrate
cansend can1 300#AC.AB.AD.AE.75.49.AD.D1
Yet it still seems like there is no CAN packets being sent or received.
(That receiving code is written in additional info. )
Plus, I tried to catch some signal with oscilloscope machine, but I couldn’t get a thing at all.
Then, I modified some lines of uEnv.txt like below, located inside the boot folder of BBB.
###Additional custom capes
uboot_overlay_addr4=/lib/firmware/BB-CAN0-00A0.dtbo
uboot_overlay_addr5=/lib/firmware/BB-CAN1-00A0.dtbo
#uboot_overlay_addr6=/lib/firmware/<file6>.dtbo
#uboot_overlay_addr7=/lib/firmware/<file7>.dtbo
###
But CAN still does not work, and config-pin command after this uEnv.txt setting shows error like below
debian@beaglebone:/lib/firmware$ config-pin -q p9.24
ERROR: open() for /sys/devices/platform/ocp/ocp:P9_24_pinmux/state failed, No such file or directory
I truly suspect there might be something wrong with the driver or pinmux setting,
because the code did work well in other situations.
The same messages for the other overlayed pins. Actually any config-pin commands don’t work on these pins. (And of course the CAN bus is still not working)
I’m currently using the latest AM3358 Debian 10.3 (2020-04-06) SD IoT image, and packages seems to be all updated well. The image is flashed and no SD card is in.
I really appreciate you read this. Thank you!
Additional Info:
CAN receive part code
#include <linux/can.h>
#include <linux/can/raw.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <fcntl.h>
int InitCanInterface(const char *ifname){
int sock = socket(PF_CAN, SOCK_RAW, CAN_RAW);
fcntl(sock, F_SETFL, O_NONBLOCK);
if (sock == -1){
printf("Fail to create CAN socket for %s - %m \n", ifname);
return -1;
}
printf("Success to create CAN socket for %s\n", ifname);
struct ifreq ifr;
strncpy(ifr.ifr_name, ifname, IFNAMSIZ - 1);
int ret = ioctl(sock, SIOCGIFINDEX, &ifr);
if (ret == -1){
perror("Fail to get CAN interface index");
return -1;
}
printf("Success to get CAN interface index: %d\n", ifr.ifr_ifindex);
struct sockaddr_can addr;
addr.can_family = AF_CAN;
addr.can_ifindex = ifr.ifr_ifindex;
ret = bind(sock, (struct sockaddr*)&addr, sizeof(addr));
if (ret == -1){
perror("Fail to bind CAN socket -");
return -1;
}
printf("Success to bind CAN socket\n");
return sock;}
int TransmitCanFrame(const int sock, const uint32_t id, const uint8_t *data, const size_t data_len){
struct can_frame frame;
frame.can_id = id & 0x1ffffff;
frame.can_id |= (1<<31);
memcpy(frame.data, data, data_len);
frame.can_dlc = data_len;
int tx_bytes = write(sock, &frame, sizeof(frame));
if (tx_bytes == -1){
perror("Fail to transmit CAN frame -");
return -1;
}
printf("Success to transmit CAN frame - %d bytes is transmitted\n", tx_bytes);
return 0;
}
#define CAN_FRAME_MAX_LEN 8
int ReceiveCanFrame(const int sock){
struct can_frame frame;
int rx_bytes = read(sock, &frame, sizeof(frame));
if (rx_bytes < 0){
//perror("Fail to receive CAN frame -");
return -1;
}
else if (rx_bytes < (int)sizeof(struct can_frame)){
printf("Incomplete CAN frame is received - rx_bytes: %d/n", rx_bytes);
return -1;
}
else if (frame.can_dlc > CAN_FRAME_MAX_LEN){
printf("Invalid dlc: %u\n", frame.can_dlc);
return -1;
}
if (((frame.can_id >> 29) & 1) ==1) {
printf("Error frame is received\n");
}
else if (((frame.can_id >> 30) & 1) ==1) {
printf("RTR frame is received\n");
}
else {
if (((frame.can_id >> 31) & 1) == 0){
printf("11bit long std CAN frame is received\n");
printf("%#x\n",frame.can_id);
}
else {
printf("29bit long ext CAN frame is received\n");
printf("%#x\n",frame.can_id & 0x0001fffffff );
}
}
for (int ii=0; ii<8; ii++) {
printf("0x%X ", frame.data[ii]);
}
printf("\n");
printf("\n");
return 0;
}
int main(){
int sock = InitCanInterface("can0");
if (sock < 0 ){
return -1;
}
// uint8_t can_data[CAN_FRAME_MAX_LEN] = {};
while(1) {
//printf("hello\n");
//printf("%d",ReceiveCanFrame(sock));
//if(ReceiveCanFrame(sock) == 0)
//printf("No response\n");
ReceiveCanFrame(sock);
sleep(1);
}
return 0;
}
uname -a outputs
debian@beaglebone:/lib/firmware$ uname -a
Linux beaglebone 4.19.94-ti-r64 #1buster SMP PREEMPT Fri May 21 23:57:28 UTC 2021 armv7l GNU/Linux
debian@beaglebone:/lib/firmware$ sudo /opt/scripts/tools/version.sh
git:/opt/scripts/:[e8ae28ccc34a177e9435a0d24cdf8421e081c19a]
eeprom:[A335BNLT00C00620BBBK11BC]
model:[TI_AM335x_BeagleBone_Black]
dogtag:[BeagleBoard.org Debian Buster IoT Image 2020-04-06]
bootloader:[eMMC-(default)]:[/dev/mmcblk1]:[U-Boot SPL 2019.04-00002-g07d5700e21 (Mar 06 2020 - 11:24:55 -0600)]:[location: dd MBR]
bootloader:[eMMC-(default)]:[/dev/mmcblk1]:[U-Boot 2019.04-00002-g07d5700e21]:[location: dd MBR]
UBOOT: Booted Device-Tree:[am335x-boneblack-uboot-univ.dts]
UBOOT: Loaded Overlay:[AM335X-PRU-RPROC-4-19-TI-00A0]
UBOOT: Loaded Overlay:[BB-ADC-00A0]
UBOOT: Loaded Overlay:[BB-BONE-eMMC1-01-00A0]
UBOOT: Loaded Overlay:[BB-CAN0-00A0]
UBOOT: Loaded Overlay:[BB-CAN1-00A0]
UBOOT: Loaded Overlay:[BB-HDMI-TDA998x-00A0]
kernel:[4.19.94-ti-r64]
nodejs:[v10.24.0]
/boot/uEnv.txt Settings:
uboot_overlay_options:[enable_uboot_overlays=1]
uboot_overlay_options:[uboot_overlay_addr4=/lib/firmware/BB-CAN0-00A0.dtbo]
uboot_overlay_options:[uboot_overlay_addr5=/lib/firmware/BB-CAN1-00A0.dtbo]
uboot_overlay_options:[uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-19-TI-00A0.dtbo]
uboot_overlay_options:[enable_uboot_cape_universal=1]
pkg check: to individually upgrade run: [sudo apt install --only-upgrade <pkg>]
pkg:[bb-cape-overlays]:[4.14.20210416.0-0~buster+20210416]
pkg:[bb-customizations]:[1.20210708.0-0~buster+20210708]
pkg:[bb-usb-gadgets]:[1.20200504.0-0~buster+20200504]
pkg:[bb-wl18xx-firmware]:[1.20210520.0-0~buster+20210520]
pkg:[kmod]:[26-1]
pkg:[librobotcontrol]:[1.0.5-git20200715.0-0~buster+20200716]
pkg:[firmware-ti-connectivity]:[20190717-2rcnee1~buster+20200305]
groups:[debian : debian adm kmem dialout cdrom floppy audio dip video plugdev users systemd-journal bluetooth netdev i2c gpio pwm eqep remoteproc admin spi iio docker tisdk weston-launch xenomai cloud9ide]
cmdline:[console=ttyO0,115200n8 bone_capemgr.uboot_capemgr_enabled=1 root=/dev/mmcblk1p1 ro rootfstype=ext4 rootwait coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100 quiet]
dmesg | grep remote
[ 65.289088] remoteproc remoteproc0: wkup_m3 is available
[ 65.320630] remoteproc remoteproc0: powering up wkup_m3
[ 65.320664] remoteproc remoteproc0: Booting fw image am335x-pm-firmware.elf, size 217148
[ 65.320951] remoteproc remoteproc0: remote processor wkup_m3 is now up
[ 68.227786] remoteproc remoteproc1: 4a334000.pru is available
[ 68.241566] remoteproc remoteproc2: 4a338000.pru is available
dmesg | grep pru
[ 68.227786] remoteproc remoteproc1: 4a334000.pru is available
[ 68.227985] pru-rproc 4a334000.pru: PRU rproc node pru@4a334000 probed successfully
[ 68.241566] remoteproc remoteproc2: 4a338000.pru is available
[ 68.241750] pru-rproc 4a338000.pru: PRU rproc node pru@4a338000 probed successfully
dmesg | grep pinctrl-single
[ 0.943044] pinctrl-single 44e10800.pinmux: 142 pins, size 568
dmesg | grep gpio-of-helper
[ 0.956633] gpio-of-helper ocp:cape-universal: ready
lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
END
dmesg for CAN
debian@beaglebone:/lib/firmware$ dmesg | grep can
[ 1.205500] c_can_platform 481cc000.can: c_can_platform device registered (regs=3377e4b7, irq=42)
[ 1.206878] c_can_platform 481d0000.can: c_can_platform device registered (regs=292aef38, irq=43)
[ 1.422353] can: controller area network core (rev 20170425 abi 9)
[ 992.007971] c_can_platform 481d0000.can can1: setting BTR=2701 BRPE=0000
[ 992.016624] IPv6: ADDRCONF(NETDEV_UP): can1: link is not ready
[ 992.017512] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready
The full uEnv.txt
debian@beaglebone:/lib/firmware$ cat /boot/uEnv.txt
#Docs: http://elinux.org/Beagleboard:U-boot_partitioning_layout_2.0
uname_r=4.19.94-ti-r64
#uuid=
#dtb=
###U-Boot Overlays###
###Documentation: http://elinux.org/Beagleboard:BeagleBoneBlack_Debian#U-Boot_Overlays
###Master Enable
enable_uboot_overlays=1
###
###Overide capes with eeprom
#uboot_overlay_addr0=/lib/firmware/<file0>.dtbo
#uboot_overlay_addr1=/lib/firmware/<file1>.dtbo
#uboot_overlay_addr2=/lib/firmware/<file2>.dtbo
#uboot_overlay_addr3=/lib/firmware/<file3>.dtbo
###
###Additional custom capes
uboot_overlay_addr4=/lib/firmware/BB-CAN0-00A0.dtbo
uboot_overlay_addr5=/lib/firmware/BB-CAN1-00A0.dtbo
#uboot_overlay_addr6=/lib/firmware/<file6>.dtbo
#uboot_overlay_addr7=/lib/firmware/<file7>.dtbo
###
###Custom Cape
#dtb_overlay=/lib/firmware/<file8>.dtbo
###
###Disable auto loading of virtual capes (emmc/video/wireless/adc)
#disable_uboot_overlay_emmc=1
#disable_uboot_overlay_video=1
#disable_uboot_overlay_audio=1
#disable_uboot_overlay_wireless=1
#disable_uboot_overlay_adc=1
###
###PRUSS OPTIONS
###pru_rproc (4.14.x-ti kernel)
#uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-14-TI-00A0.dtbo
###pru_rproc (4.19.x-ti kernel)
uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-19-TI-00A0.dtbo
###pru_uio (4.14.x-ti, 4.19.x-ti & mainline/bone kernel)
#uboot_overlay_pru=/lib/firmware/AM335X-PRU-UIO-00A0.dtbo
###
###Cape Universal Enable
enable_uboot_cape_universal=1
###
###Debug: disable uboot autoload of Cape
#disable_uboot_overlay_addr0=1
#disable_uboot_overlay_addr1=1
#disable_uboot_overlay_addr2=1
#disable_uboot_overlay_addr3=1
###
###U-Boot fdt tweaks... (60000 = 384KB)
#uboot_fdt_buffer=0x60000
###U-Boot Overlays###
cmdline=coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100 quiet
#In the event of edid real failures, uncomment this next line:
#cmdline=coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100 quiet video=HDMI-A-1:1024x768@60e
##enable Generic eMMC Flasher:
##make sure, these tools are installed: dosfstools rsync
#cmdline=init=/opt/scripts/tools/eMMC/init-eMMC-flasher-v3.sh