Posts made by user5456

I need to write one byte to my SPI peripheral and then read 3 bytes back while keeping CS asserted. My code is given below. Though my peripheral is responding, i'm reading zeroes in my code.

        unsigned char writeBuff[1] = { 0x1F };
        unsigned char readBuff[3]{ 42, 42, 42 };

        spi_ioc_transfer xfer[2]{};

        xfer[0].len = sizeof(writeBuff);
        xfer[0].tx_buf = (unsigned long)(writeBuff);

        xfer[1].len = sizeof(readBuff);
        xfer[1].rx_buf = (unsigned long)(readBuff);

        int status = ioctl(spiFd, SPI_IOC_MESSAGE(2), &xfer);
        if (status < 0) {
                printf("ERR: Failed to read %d\n", errno);
                exit(1);
        }

        for (auto i : readBuff) {
                std::cout << +i << " ";
        }
        std::cout << "\n";
        return 0;

How does SPI flash driver affect watchdog?

Wonder how onion does uboot development. Do they directly access the NOR flash ?

I've got JTAG to work with the board, but i can only control the CPU but not the internal flash. I tried compiling a uboot image that can be run from RAM, but did not have much luck with that. Has anyone used JTAG with onion before?

@crispyoz said in Are MAC addresses unique?:

I would suggest that while you could use the MAC address as a serial number, it is not a good idea

Why not? whats wrong with it?

I was planning to use the MAC address as a serial number. Are they unique? say across 2000 onions.

I would like to replace the uboot with my own custom one. Before i start working on it, i want to know how to recover if in case i accidentally brick it. Is the internal flash accessible over the SPI pins?

When powered directly, without the dev board, power consumption is as expected 141mA@3V3 when idling with WiFi off.

Like i mentioned, I'm using a 2SP module on the development board with power being measured at the input USB cable.

According to the datasheet "Idle and WiFi turned off" should have a current consumption of 130mA at 3V3 (429mW), but when measured on the USB 5v on the eval board I'm getting 165mA(825mW). Could someone tell me why the power is almost double?