Fu-. 0 Posted January 18 Question about GPIO2C6 and GPIO2C7 pins. It is possible to set them to GPIO using wiringPi, but the voltage at HIGH output is lower than other GPIO pins. It is only about 1.95V. Upon further investigation, I found that a clock-like waveform is output during HIGH output. GPIO2C6 is exclusive with SPI5_CLK and GPIO2C7 is exclusive with SPI5_CSN, but it appears that the SPI5 clock continues to be output when each pin is set as a GPIO. Any suggestions? Share this post Link to post Share on other sites
tooz 54 Posted January 20 hello @Fu-., setting spi is not supported in wiringpi what are you setting for gpio2c6 and gpio2c7 and what's your configuration? Share this post Link to post Share on other sites
Fu-. 0 Posted January 20 (edited) hello @tooz I'm setting both pins as GPIO. I don't want these pin as using SPI, just only GPIO. Edited January 20 by Fu-. Share this post Link to post Share on other sites
tooz 54 Posted January 21 hello @Fu-., have you tried using sysfs instead? Share this post Link to post Share on other sites
Fu-. 0 Posted January 21 hello @tooz I tried setting via sysfs gpio, it seemed to be the same behavor. Share this post Link to post Share on other sites
tooz 54 Posted January 21 hello @Fu-., from what you decribed it's possible that it might be a hardware issue, but i'm not 100% sure. have you also modified the settings of /boot/config.txt ? Share this post Link to post Share on other sites
Fu-. 0 Posted January 21 hello @tooz Yes, I've changed /boot/config.txt Before: #intf:spi5=off After: intf:spi5=off gpioall says GPIO2C6 and C7 are GPIO, also I can control the signals HIGH,and LOW. When signal is HIGH, the voltage is lower than other GPIO pins. It is only about 1.95V. Moreover, I 've confirmed that the waveform was going up and down like an SPI clock even though it was holding HIGH. I wonder why signal is oscllating? and why the voltage is too low? Share this post Link to post Share on other sites
tooz 54 Posted January 22 heloo @Fu-., looks they're in spi mode. to further investigate the issue: 1. which version of the os are you using? 2. is tinker board 2s connected to other peripherals/ components? Share this post Link to post Share on other sites
Fu-. 0 Posted January 23 hello @tooz 1.Tinker_Board_2-Debian-Bullseye-v3.0.20-20240527 2.No. A notice point: I checked I/O status with io command. io -4 0xff77e008 ff77e008: 00000000 both pins are GPIO. io -4 0xff760334 ff760334: 0000e233 clk_spi5_src_en is set, seems to disable SPI clock Share this post Link to post Share on other sites
