Jetson no transmit data is slave mode

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

Hello.
I am trying to set up communication between stm32 and jetson. Jetson is in slave mode.
I set up jetson to receive data from stm32 and I receive data in jetson.
But I can’t send data from jetson.
How can I do it?
I modified spidev_test.c
in this case I get data

static void transfer(int fd, uint8_t const *tx, uint8_t const *rx, size_t len)
{
	int ret;
	int out_fd;
	struct spi_ioc_transfer tr = {
                .tx_buf = 0,//(unsigned long)tx,
		.rx_buf = (unsigned long)rx,
                .len = 30,
                .delay_usecs = 1000,
                .speed_hz = 328125,
		.bits_per_word = bits,
	};
	if (mode & SPI_TX_QUAD)
		tr.tx_nbits = 4;
	else if (mode & SPI_TX_DUAL)
		tr.tx_nbits = 2;
	if (mode & SPI_RX_QUAD)
		tr.rx_nbits = 4;
	else if (mode & SPI_RX_DUAL)
		tr.rx_nbits = 2;
	if (!(mode & SPI_LOOP)) {
		if (mode & (SPI_TX_QUAD | SPI_TX_DUAL))
			tr.rx_buf = 0;
		else if (mode & (SPI_RX_QUAD | SPI_RX_DUAL))
			tr.tx_buf = 0;
	}
        for (int i = 10; i > 0;){
            usleep(1);
            ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
            if (ret < 0)
                continue;
            i--;
            printf("ret = %d ", ret);
            hex_dump(rx, len, ret, "RX");
        }
}

but if I uncommited line

 .tx_buf = (unsigned long)tx,

program is waiting

2

Moving this topic to the Jetson Nano category.

4

Have reference to below topic. Also confirm if modify device tree to enable Nano SPI as slave mode.

5

Hi, ShaneCCC.
Yes, I modified device tree.
I send packet (30 bytes) from STM32 in master mode and receive this packet (30 bytes) in nano.
But when I try send some data (30 bytes) from nano to STM32 - I can’t

6

I configured spidev1 as slave and spidev0 as master.

I connected
24<->18 (CS0)
13<->23 (SCK)
22<->21 (Din)
19<->37 (Dout)

 sudo ./spidev_test -D /dev/spidev0.0 -s 100000 -p4 -n1 -g30 -zzz
using device: /dev/spidev0.0
setting spi mode for read,write
setting spi bpw
setting max speed for rd/wr
spi mode: 0
bits per word: 8 bytes per word: 1
max speed: 100000 Hz (100 KHz)
no. runs: 1
Using seed:0x631ed54a
loop count = 0 
Using rand() buffer 
Using crc check 
transfer packet bytes [30]
0000: FE EE CA AB 68 83 DF 7B 00 00 12 00 75 84 4A 18 
0010: 69 38 9E C1 F7 88 CF E2 C7 2F 0A 2D 23 8B 
transfer: Return actual transfer length: 30
receive packet bytes [30]
0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
0010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
transfer: received packet size:30 len:0 stat:-6
transfer: received packet size:29 len:0 stat:-6
transfer: received packet size:28 len:0 stat:-6
transfer: received packet size:27 len:0 stat:-6
transfer: received packet size:26 len:0 stat:-6
transfer: received packet size:25 len:0 stat:-6
transfer: received packet size:24 len:0 stat:-6
transfer: received packet size:23 len:0 stat:-6
transfer: received packet size:22 len:0 stat:-6
transfer: received packet size:21 len:0 stat:-6
transfer: received packet size:20 len:0 stat:-6
transfer: received packet size:19 len:0 stat:-6
transfer: received packet size:18 len:0 stat:-6
transfer: received packet size:17 len:0 stat:-6
transfer: received packet size:16 len:0 stat:-6
transfer: received packet size:15 len:0 stat:-6
transfer: received packet size:14 len:0 stat:-6
transfer: received packet size:13 len:0 stat:-6
transfer: received packet size:12 len:0 stat:-6
/dev/spidev0.0: TEST FAILED !!!!! (status:-1)
====== Transfer stats ====
Transmit:
       total: 30B (0KiB 0MiB)
       total: 1P 
       ioerr: 0B (0KiB 0MiB)
       ioerr: 0P
 Rate:
  wire total: -1B/s (0KB/s)
       total: -1B/s (0KB/s)
  wire total: -1P/s
       total: -1P/s
Receive:
       total: 30B (0KiB 0MiB)
       total: 0P 
        good: 0B (0KiB 0MiB)
        good: 0P
       ioerr: 0P
     dataerr: 0P
 Rate:
        good: -1B/s (0KB/s)
        good: -1P/s
 packet drop: -1/10000

  Total time: 0.003766s


sudo ./spidev_test -D /dev/spidev1.0 -s 100000 -p4 -n1 -g30 -zzz -r
Disabling transmit
using device: /dev/spidev1.0
setting spi mode for read,write
setting spi bpw
setting max speed for rd/wr
spi mode: 0
bits per word: 8 bytes per word: 1
max speed: 100000 Hz (100 KHz)
no. runs: 1
Using seed:0x631ed547
loop count = 0 
transfer: Return actual transfer length: 30
receive packet bytes [30]
0000: FE EE CA AB 68 83 DF 7B 00 00 12 00 75 84 4A 18 
0010: 69 38 9E C1 F7 88 CF E2 C7 2F 0A 2D 23 8B 
transfer: received packet size:30 len:18 stat:0
/dev/spidev1.0: TEST PASSED 
====== Transfer stats ====
Receive:
       total: 30B (0KiB 0MiB)
       total: 1P 
        good: 30B (0KiB 0MiB)
        good: 1P
       ioerr: 0P
     dataerr: 0P
 Rate:
        good: 11B/s (0KB/s)
        good: 0P/s
 packet drop: -1/10000

  Total time: 2.722988s

How can I check the transmission from slave to master?

8

Why configure as master mode to transfer data from Nano?

9

I wanted to show the output. In the future, the master mode on the nano will not be used.