# voxl_spi_init, failed to open /dev/spidev device: No such file or directory. Source: https://forum.modalai.com/topic/3255/voxl_spi_init-failed-to-open-dev-spidev-device-no-such-file-or-directory Category: FAQs (https://forum.modalai.com/category/4/faqs) Posted: 2024-03-24 04:43:40 UTC by 이광철 Replies: 29 · Views: 9320 ## 이광철 · 2024-03-24 04:43:40 UTC Hello. I have voxl2 mini. The system and kernel versions are as follows. system-image: 1.7.1-M0104-14.1a-perf-nightly-20231025 kernel: #1 SMP PREEMPT Thu Oct 26 04:23:26 UTC 2023 4.19.125 hw version: M0104 voxl-suite: 1.1.2 I want to use j10 External UART in spi mode. I called the voxl_spi_init function as below. SPI_BUS = 14; if (voxl_spi_init(SPI_BUS, SPI_MODE_0, 12000000) < 0) return FALSE; The result is ERROR in voxl_spi_init, failed to open /dev/spidev device: No such file or directory. The results of ls -al /dev/spi* are as follows: crw------- 1 root root 153, 0 Mar 2 2023 spidev0.0 crw------- 1 root root 153, 1 Mar 2 2023 spidev3.0 The result of voxl-gpio -r 67 are as follows: 1 where is spidev14.0? Or what am I doing wrong? Thanks. ## Reply by Alex Kushleyev (ModalAI staff) · 2024-03-25 15:31:14 UTC @이광철 , Make sure you are using correct spi device path. ``` voxl2:/$ ls /dev/spidev* /dev/spidev0.0 /dev/spidev11.0 /dev/spidev14.0 /dev/spidev3.0 ``` ## Reply by admin (ModalAI staff) · 2024-03-25 23:52:58 UTC Hi @이광철 , We defaulted this interface to SPI starting in SDK 1.1.2. https://docs.modalai.com/voxl2-mini-linux-user-guide/#system-image-17 https://docs.modalai.com/voxl2-voxl2-mini-system-image/#system-image-changelog ![ae312240-e5ce-4587-be4d-b8c5d045463d-image.png](https://forum.modalai.com/assets/uploads/files/1711410556622-ae312240-e5ce-4587-be4d-b8c5d045463d-image.png) It can be converted back to SPI with a kernel change and rebuild if you are able to try that. https://docs.modalai.com/voxl2-kernel-build-guide/ Enable: https://gitlab.com/voxl-public/system-image-build/meta-voxl2-bsp/-/blob/qrb5165-ubun1.0-14.1a/recipes-kernel/linux-msm/files/dts/m0104/m0104-modalai-qupv3.dtsi?ref_type=heads#L93 Disable: https://gitlab.com/voxl-public/system-image-build/meta-voxl2-bsp/-/blob/qrb5165-ubun1.0-14.1a/recipes-kernel/linux-msm/files/dts/m0104/m0104-modalai-qupv3.dtsi?ref_type=heads#L98 ## Reply by 이광철 · 2024-03-26 00:59:32 UTC (in reply to admin) @admin Do I need to change the kernel to use spi14 using the voxl_spi_init function? or Is this possible using voxl2_SDK_1.1.1? Thanks ## Reply by Alex Kushleyev (ModalAI staff) · 2024-03-26 01:29:35 UTC (in reply to 이광철) @이광철 yes, you have to to switch the kernel. you can try using the old kernel from sdk 1.1.1. You can test it before flashing permanently : https://docs.modalai.com/voxl2-kernel-build-guide/#test . I dont see any significant changes in 1.1.2 that may affect you, but you should test before overwriting your kernel ## Reply by 이광철 · 2024-03-27 02:20:06 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev Hi. I rebuilt the kernel referring to your advice. The modified contents are as follows. modify file: build_mount/lu.um.1.2.1/apps_proc/poky/meta-voxl2-bsp/recipes-kernel/linux-msm/files/dts/m0104/m0104-modalai-qupv3.dtsi /* M0104 - J10 - GPIO 40-44 */ &qupv3_se14_spi { status = "ok"; }; /* M0104 - J10 JST connector */ &qupv3_se14_2uart { status = "ok"; }; ./qrb5165-clean.sh ./qrb5165-build.sh -m M0104 After building the kernel, ttyMSM0 was created in /dev. However, spidev14.0 is still not found. ls /dev/spidev* spidev0.0 spidev3.0 I'm looking forward to your advice. Thanks. ## Reply by Alex Kushleyev (ModalAI staff) · 2024-03-27 02:22:31 UTC (in reply to 이광철) @이광철 , you need to disable uart: ``` /* M0104 - J10 JST connector */ &qupv3_se14_2uart { status = "disabled"; }; ``` ## Reply by 이광철 · 2024-03-27 03:24:17 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev First of all thank you for your advice. build_mount/lu.um.1.2.1/apps_proc/poky/meta-voxl2-bsp/recipes-kernel/linux-msm/files/dts/m0104/m0104-modalai-qupv3.dtsi /* M0104 - J10 - GPIO 40-44 */ &qupv3_se14_spi { status = "ok"; }; /* M0104 - J10 JST connector */ &qupv3_se14_2uart { status = "disabled"; }; Modified as above. After building the kernel, the contents of /dev are as follows. Why doesn't spidev14.0 exist? What am I doing wrong? voxl2-mini:/dev$ ls spidev* spidev0.0 spidev3.0 voxl2-mini:/dev$ ls tty* tty tty10 tty13 tty16 tty19 tty21 tty24 tty27 tty3 tty32 tty35 tty38 tty40 tty43 tty46 tty49 tty51 tty54 tty57 tty6 tty62 tty8 ttyprintk tty0 tty11 tty14 tty17 tty2 tty22 tty25 tty28 tty30 tty33 tty36 tty39 tty41 tty44 tty47 tty5 tty52 tty55 tty58 tty60 tty63 tty9 tty1 tty12 tty15 tty18 tty20 tty23 tty26 tty29 tty31 tty34 tty37 tty4 tty42 tty45 tty48 tty50 tty53 tty56 tty59 tty61 tty7 ttyMSM0 ## Reply by Alex Kushleyev (ModalAI staff) · 2024-03-27 03:32:07 UTC (in reply to 이광철) @이광철 , just to double check.. after building the kernel, did you install it to voxl2 mini? If all else fails, you can test (without overwriting) the kernel from SDK 1.1.1 like this : ``` voxl2-mini_SDK_1.1.1/system-image$ adb reboot bootloader voxl2-mini_SDK_1.1.1/system-image$ fastboot boot qti-ubuntu-robotics-image-m0104-boot.img Sending 'boot.img' (17552 KB) OKAY [ 0.509s] Booting OKAY [ 0.033s] Finished. Total time: 0.553s ``` then `adb` into the device and check spi port in `/dev/` ## Reply by 이광철 · 2024-03-27 03:56:13 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev just to double check.. after building the kernel, did you install it to voxl2 mini? Yes I built the kernel and installed it on voxl2-mini. The process is as follows. C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>adb reboot bootloader C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>fastboot flash boot_a qti-ubuntu-robotics-image-m0104-boot.img Sending 'boot_a' (20088 KB) OKAY [ 0.458s] Writing 'boot_a' OKAY [ 0.026s] Finished. Total time: 0.637s C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>fastboot flash boot_b qti-ubuntu-robotics-image-m0104-boot.img Sending 'boot_b' (20088 KB) OKAY [ 0.463s] Writing 'boot_b' OKAY [ 0.032s] Finished. Total time: 0.654s C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>fastboot reboot Rebooting OKAY [ 0.001s] Finished. Total time: 0.006s C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>adb wait-for-device C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>adb shell ▂▂▂▂▂▂▂▂▂▂▂▂▂ ▂▄▆▆██▛▀▀▀▀▀▀▀▀▜████▆▆▄▂ ███╗ ███╗ ██████╗ ██████╗ █████╗ ██╗ ▗▆████▀▔ ▔▔▀▀▀▀▚▄ ████╗ ████║██╔═══██╗██╔══██╗██╔══██╗██║ ▗▟████▀ ▗██▖ ▐█ ▝▀▆▄▄▄ ██╔████╔██║██║ ██║██║ ██║███████║██║ ▟████▀ ▗█▘▝█▖ ▐█ ▜█▀█▄ ██║╚██╔╝██║██║ ██║██║ ██║██╔══██║██║ █▌ ▐█▌ ▗█▘ ▝█▖ ▐█ ▐▄ ▄█ ██║ ╚═╝ ██║╚██████╔╝██████╔╝██║ ██║███████╗ ▀████ ▗█▘ ▝█▖ ▐█ ▂▄███▀ ╚═╝ ╚═╝ ╚═════╝ ╚═════╝ ╚═╝ ╚═╝╚══════╝ ▀▀██▄▄ ▂▆███▀ ▀▀██▄▄ ▀▀▆▄▄▄▄▆██▀▀▀▘ -------------------------------------------------------------------------------- system-image: 1.7.1-M0104-14.1a-perf-nightly-20231025 kernel: #1 SMP PREEMPT Wed Mar 27 02:44:30 UTC 2024 4.19.125 -------------------------------------------------------------------------------- hw version: M0104 -------------------------------------------------------------------------------- voxl-suite: 1.1.2 -------------------------------------------------------------------------------- no current network connection -------------------------------------------------------------------------------- ## Reply by 이광철 · 2024-03-27 04:20:16 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev I downloaded voxl2-mini_SDK_1.1.1.tar.gz from https://developer.modalai.com/asset/eula-download/141 It was tested as follows. C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>adb reboot bootloader C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>fastboot boot qti-ubuntu-robotics-image-m0104-boot.img Sending 'boot.img' (17548 KB) OKAY [ 0.382s] Booting OKAY [ 0.034s] Finished. Total time: 0.471s C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>adb shell ▂▂▂▂▂▂▂▂▂▂▂▂▂ ▂▄▆▆██▛▀▀▀▀▀▀▀▀▜████▆▆▄▂ ███╗ ███╗ ██████╗ ██████╗ █████╗ ██╗ ▗▆████▀▔ ▔▔▀▀▀▀▚▄ ████╗ ████║██╔═══██╗██╔══██╗██╔══██╗██║ ▗▟████▀ ▗██▖ ▐█ ▝▀▆▄▄▄ ██╔████╔██║██║ ██║██║ ██║███████║██║ ▟████▀ ▗█▘▝█▖ ▐█ ▜█▀█▄ ██║╚██╔╝██║██║ ██║██║ ██║██╔══██║██║ █▌ ▐█▌ ▗█▘ ▝█▖ ▐█ ▐▄ ▄█ ██║ ╚═╝ ██║╚██████╔╝██████╔╝██║ ██║███████╗ ▀████ ▗█▘ ▝█▖ ▐█ ▂▄███▀ ╚═╝ ╚═╝ ╚═════╝ ╚═════╝ ╚═╝ ╚═╝╚══════╝ ▀▀██▄▄ ▂▆███▀ ▀▀██▄▄ ▀▀▆▄▄▄▄▆██▀▀▀▘ -------------------------------------------------------------------------------- system-image: 1.7.1-M0104-14.1a-perf-nightly-20231025 kernel: #1 SMP PREEMPT Thu Oct 26 04:23:26 UTC 2023 4.19.125 -------------------------------------------------------------------------------- hw version: M0104 -------------------------------------------------------------------------------- voxl-suite: 1.1.2 -------------------------------------------------------------------------------- no current network connection -------------------------------------------------------------------------------- spidev14.0 still does not exist. There is something strange. Why voxl-suite: 1.1.2? voxl-suite: 1.1.1 Isn't that correct? ## Reply by Alex Kushleyev (ModalAI staff) · 2024-03-27 04:50:22 UTC (in reply to 이광철) @이광철 , if you update just the kernel (or boot using a temporary one), the rest of the file system is unaffected, so voxl suite will remain the same. You can look at the kernel build dates to see the difference (it is also printed when you start adb shell). I am not sure why spi is not showing up, will need to ask @admin ## Reply by Alex Kushleyev (ModalAI staff) · 2024-03-27 04:57:35 UTC (in reply to Alex Kushleyev) Maybe the change spi ->uart was actually made before sdk 1.1.1. We will need to double check that. ## Reply by Alex Kushleyev (ModalAI staff) · 2024-03-27 14:06:27 UTC (in reply to Alex Kushleyev) I confirmed that kernel from SDK 1.1.1 does not have the spi mapped. So i tried the kernel from SDK 1.0.0 and it does. In this case my board has SDK 1.1.1 installed, but i am booting into kernel from SDK 1.0.0. ``` voxl2/builds/voxl2-mini_SDK_1.0.0/system-image$ adb reboot bootloader voxl2/builds/voxl2-mini_SDK_1.0.0/system-image$ fastboot boot qti-ubuntu-robotics-image-m0104-boot.img Sending 'boot.img' (17552 KB) OKAY [ 0.508s] Booting OKAY [ 0.034s] Finished. Total time: 0.573s ... adb shell system-image: 1.7.1-M0104-14.1a-perf-nightly-20231025 kernel: #1 SMP PREEMPT Fri May 19 22:53:15 UTC 2023 4.19.125 -------------------------------------------------------------------------------- hw version: M0104 -------------------------------------------------------------------------------- voxl-suite: 1.1.1 -------------------------------------------------------------------------------- no current network connection -------------------------------------------------------------------------------- voxl2-mini:/$ ls /dev/spidev* /dev/spidev0.0 /dev/spidev11.0 /dev/spidev14.0 /dev/spidev3.0 ``` Now, i am not sure why your manual kernel build did not work. if you still cannot get it to work, let us know, we can build it with spi enabled and test it for you. ## Reply by 이광철 · 2024-03-28 01:12:12 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev I downloaded voxl2-mini_SDK_1.0.0.tar.gz from https://developer.modalai.com/asset/eula-download/127 It was tested as follows. C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>adb reboot bootloader C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>fastboot flash boot_a qti-ubuntu-robotics-image-m0104-boot.img Sending 'boot_a' (17552 KB) OKAY [ 0.399s] Writing 'boot_a' OKAY [ 0.023s] Finished. Total time: 0.565s C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>fastboot flash boot_b qti-ubuntu-robotics-image-m0104-boot.img Sending 'boot_b' (17552 KB) OKAY [ 0.397s] Writing 'boot_b' OKAY [ 0.019s] Finished. Total time: 0.561s C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>fastboot reboot Rebooting OKAY [ 0.000s] Finished. Total time: 0.005s C:\Users\User\Desktop\OpenSDP\platform-tools_r33.0.3-windows\platform-tools>adb shell -------------------------------------------------------------------------------- system-image: 1.7.1-M0104-14.1a-perf-nightly-20231025 kernel: #1 SMP PREEMPT Fri May 19 22:53:15 UTC 2023 4.19.125 -------------------------------------------------------------------------------- hw version: M0104 -------------------------------------------------------------------------------- voxl-suite: 1.1.2 -------------------------------------------------------------------------------- no current network connection -------------------------------------------------------------------------------- voxl2-mini:/dev$ ls spi* spidev0.0 spidev11.0 spidev14.0 spidev3.0 OK! The spidev14.0 file exists. I tested it as below: voxl2-mini:/dev$ qrb5165io-spi-test -d 0 failed to ping icm42688p IMU voxl2-mini:/dev$ qrb5165io-spi-test -d 11 failed to ping icm42688p IMU voxl2-mini:/dev$ qrb5165io-spi-test -d 3 [INFO] success! ICM42688 Detected voxl2-mini:/dev$ qrb5165io-spi-test -d 14 There is no response to the qrb5165io-spi-test -d 14 command. is this right? Is spidev14.0 not working? ## Reply by Alex Kushleyev (ModalAI staff) · 2024-03-28 02:23:25 UTC (in reply to 이광철) @이광철 , do you have anything connected to spidev14.0 ? You need a device connected to the spi port. If you look at the source code for this test app, it simply tries to ping a specific IMU device, which happens to be installed on board on SPI3 (ICM42688 IMU) : https://gitlab.com/voxl-public/voxl-sdk/core-libs/libqrb5165-io/-/blob/master/apps/examples/qrb5165io-spi-test.c So, you should connect your desired device to J10 and modify the example to communicate with your device. Also, based on this documentation, https://docs.modalai.com/voxl2-mini-connectors/#j10-pin-out-spi-mode-gpio_67--low-kernel-rebuild-required-to-use, you need to set the GPIO before using: ``` voxl-gpio -w 67 1 ``` I hope that helps ## Reply by Alex Kushleyev (ModalAI staff) · 2024-03-28 02:51:12 UTC (in reply to Alex Kushleyev) Another quick tip for testing SPI stuff. I found this useful: https://github.com/rm-hull/spidev-test/blob/master/spidev_test.c You can download this file to VOXL2, build it using ``` gcc -O2 spidev_test.c -o spidev_test ``` and then you can actually query the IMU on spi 3: ``` voxl2-mini:~$ ./spidev_test -D /dev/spidev3.0 -p "\x76\x00\xF5\x00" spi mode: 0x0 bits per word: 8 max speed: 500000 Hz (500 KHz) RX | 00 00 00 47 ... ``` and from [here](https://gitlab.com/voxl-public/voxl-sdk/core-libs/libqrb5165-io/-/blob/master/apps/examples/qrb5165io-spi-test.c?ref_type=heads#L54) we know that 0x47 is actually the value WHOAMI register of ICM42688 IMU :) The data i am sending to the device is 4 bytes used to query the imu, as done [here](https://gitlab.com/voxl-public/voxl-sdk/core-libs/libqrb5165-io/-/blob/master/apps/examples/qrb5165io-spi-test.c?ref_type=heads#L65) . the value `0xF5 = 0x75 | 0x80` which tells the IMU to send back the value of register `0x75` ## Reply by 이광철 · 2024-03-28 03:46:07 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev I will connect my spi device and let you know the results after testing. Thanks for your help. ## Reply by 이광철 · 2024-04-03 03:35:46 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev Hi. I tested it by connecting my spi device to j10. This spi device is working normally in voxl2. My program for testing also operates normally with this spi device in voxl2. However, when I test the spi device and test program on voxl mini, there is no response to the voxl_spi_write function. Also, the test below is the same as before. voxl2-mini:/dev$ qrb5165io-spi-test -d 14 There is no response to the qrb5165io-spi-test -d 14 command. I need your help and thanks in advance. ## Reply by 이광철 · 2024-04-03 04:44:45 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev I tested according to your advice. This is the result of testing on my mini. voxl2-mini:~$ cd /usr/bin voxl2-mini:/usr/bin$ spidev_test -D /dev/spidev3.0 -p "\x76\x00\xF5\x00" spi mode: 0x0 bits per word: 8 max speed: 500000 Hz (500 KHz) can't send spi message: Invalid argument Aborted ## Reply by 이광철 · 2024-04-03 04:51:07 UTC (in reply to 이광철) @이광철 Alex-Kushleyev sorry. voxl2-mini:~$ cd /usr/bin voxl2-mini:/usr/bin$ spidev_test -D /dev/spidev3.0 -p "\x76\x00\xF5\x00" spi mode: 0x0 bits per word: 8 max speed: 500000 Hz (500 KHz) can't send spi message: Invalid argument Aborted This test was my mistake. Below are the final test results. voxl2-mini:/usr/bin$ spidev_test -D /dev/spidev3.0 -p "\x76\x00\xF5\x00" spi mode: 0x0 bits per word: 8 max speed: 500000 Hz (500 KHz) RX | 00 00 00 47 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ | ...G ## Reply by Alex Kushleyev (ModalAI staff) · 2024-04-03 19:09:17 UTC (in reply to 이광철) @이광철 , Please note that `qrb5165io-spi-test -d 14` is a test app that just tries to detect a specific IMU on the SPI port. If the specific IMU is not connected, the test will not be successful. Are you able to read any data from your SPI sensor (using `spidev_test -D /dev/spidev14.0 ... `? Can you share what your sensor is? You should look in the documentation of your sensor and it will tell you how to communicate with it. SPI protocol for reading / writing is specific to the device. Also, don't forget about the gpio setting that needs to be made before using SPI 14 (`voxl-gpio -w 67 1`). this needs to be run after each reboot. Alex ## Reply by 이광철 · 2024-04-04 02:35:29 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev Please note that qrb5165io-spi-test -d 14 is a test app that just tries to detect a specific IMU on the SPI port. If the specific IMU is not connected, the test will not be successful. Yes I know. My spi device and test program works fine on volx2's J10. Please refer to j10 in the url below. https://docs.px4.io/main/en/flight_controller/modalai_voxl_2.html ## Reply by Alex Kushleyev (ModalAI staff) · 2024-04-04 03:09:38 UTC (in reply to 이광철) @이광철 , do you still have any issue? Does spidev_test work with spi 14? ## Reply by 이광철 · 2024-04-04 03:14:00 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev I tested it by connecting my spi device to j10. This spi device is working normally in voxl2. My program for testing also operates normally with this spi device in voxl2. voxl_spi_init(SPI_BUS, SPI_MODE_0, VOXL_SPI_MAX_SPEED) is OK but, there is no response to the voxl_spi_write function. ## Reply by Alex Kushleyev (ModalAI staff) · 2024-04-04 03:15:58 UTC (in reply to 이광철) @이광철 , can you confirm that you are setting gpio 67 on voxl2 mini before testing spi 14? ## Reply by 이광철 · 2024-04-04 03:21:22 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev Yes. After executing voxl-gpio -w 67 1, run my test. voxl-gpio -r 67 1 ## Reply by Alex Kushleyev (ModalAI staff) · 2024-04-04 05:08:40 UTC (in reply to 이광철) Hmm.. we will investigate. ## Reply by modaltb (ModalAI staff) · 2024-04-08 16:36:33 UTC Hi @이광철 Sorry for missing guidance, I do think an alias is also needed like this: https://gitlab.com/voxl-public/system-image-build/meta-voxl2-bsp/-/commit/e97a22de6b4e5582fc276a963b958d01a478d56b#999b45d40c8aafd81669d788073c2ea1315dac66_66_62 Also for this to work, I believe you will want to use the older devcfg.mbn file as well from SDK 1.0.0 as that has trustzone setup for SPI, and the new devcfg.mbn is setup for UART. If trustzone isn't configured correctly I do think the kernel halts on bootup. Flashing devcfg.mbn is like this, which is likely needed once alias is setup, to convert back to SPI from UART. fastboot flash devcfg_a devcfg.mbn fastboot flash devcfg_b devcfg.mbn ## Reply by 이광철 · 2024-04-09 01:20:03 UTC (in reply to modaltb) @modaltb Hi. I try a test on voxl-mini with your advice applied. voxl-mini sdk version is 1.0.0 My program and spi device operates is normal. Thanks for your advice.