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#91
NXP / Re: 1-Wire and 1.8 V on GPIO o...
Last post by ilario - August 29, 2025, 01:07:56 PMFantastic idea, thanks!!!
I will use the I2C and the SPI of the UEXT, but I am not planning to use the UART. So I can use the 2 UART pins from the UEXT
In the i.MX 8M Plus datasheet, I can see that the "ECSPI1_MOSI" AC20 and the "ECSPI1_SCLK" AF20 (exposed at the UEXT, after level shifting, as UEXT_TDX pin #3 and UEXT_RXD pin #4) have a pull down: "Input with PD".
For 1-wire seems that I have to use a pull up, do you think it is safe if I add a stronger pull up after the UEXT?
From the datasheet, seeeems that the pull-down resistor has a strength of 20-40 kOhm, so maybe I could add a pull-up of something like 2.2 kOhm? Does it sound like a good idea?
What still sounds like complicated is to use one of those pins with a DeviceTree overlay. I should free them from the UART3 before, right?
Should it be enough to set the UART3 to
Thanks!
I will use the I2C and the SPI of the UEXT, but I am not planning to use the UART. So I can use the 2 UART pins from the UEXT
In the i.MX 8M Plus datasheet, I can see that the "ECSPI1_MOSI" AC20 and the "ECSPI1_SCLK" AF20 (exposed at the UEXT, after level shifting, as UEXT_TDX pin #3 and UEXT_RXD pin #4) have a pull down: "Input with PD".
For 1-wire seems that I have to use a pull up, do you think it is safe if I add a stronger pull up after the UEXT?
From the datasheet, seeeems that the pull-down resistor has a strength of 20-40 kOhm, so maybe I could add a pull-up of something like 2.2 kOhm? Does it sound like a good idea?
What still sounds like complicated is to use one of those pins with a DeviceTree overlay. I should free them from the UART3 before, right?
Should it be enough to set the UART3 to
Code Select
status = "disabled";in the Device Tree?Thanks!
#92
RK3188 / [RK3328-SOM-EVB] Using UART1
Last post by cybernox - August 29, 2025, 12:19:11 PMI'm working with the RK3328 SOM (RK3328-SOM-EVB) and official bookworm downloaded from https://images.olimex.com/release/RK3328-SOM/RK3328-SOM-bookworm-minimal-20241127-120000.img.7z
I'm trying to enable UART1 but it's not working.
Here's what I have tried so far:
Enabled UART1 using armbian-config → rebooted, but the UART did not appear.
Created a custom Device Tree overlay targeting /serial@ff120000 and set the pinmux for GPIO3_A4/6 to function 5 → rebooted, but the UART still does not appear.
I created a dts inspired by the pinout in the datasheet
Then compiled
added mine in the file /boot/armbianEnv.txt
instead of the standard one that was
but nothing...
various diagnostic commands returns always the same result
output:
executed:
Output: disabled
Instead
give me the result okay (I suppose that this is the serial console uart, tested and working)
The command
return always
Output shows only ff130000.serial: ttyS2 (console/debug).
Despite these attempts, /dev/ttyS* does not show UART1, and the status of serial@ff120000 remains disabled.
Could you please confirm:
Which node corresponds to UART1 on the Olimex RK3328 SOM?
The correct pinmux/function settings for GPIO3_A4 (TX) and GPIO3_A6 (RX) for UART1.
Any known issues or additional steps needed to enable UART1 under Armbian?
Thank you very much for your help!
I'm trying to enable UART1 but it's not working.
Here's what I have tried so far:
Enabled UART1 using armbian-config → rebooted, but the UART did not appear.
Created a custom Device Tree overlay targeting /serial@ff120000 and set the pinmux for GPIO3_A4/6 to function 5 → rebooted, but the UART still does not appear.
I created a dts inspired by the pinout in the datasheet
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/dts-v1/;
/plugin/;
/ {
compatible = "rockchip,rk3328";
fragment@0 {
target-path = "/serial@ff120000";
__overlay__ {
status = "okay";
};
};
fragment@1 {
target = <&pinctrl>;
__overlay__ {
uart1_pins: uart1_pins {
rockchip,pins = <
3 4 5 /* TX -> GPIO3_A4, mode 5 */
3 6 5 /* RX -> GPIO3_A6, mode 5 */
>;
function = "uart";
};
};
};
};
Then compiled
Code Select
dtc -@ -I dts -O dtb -o /boot/dtb/rockchip/rk3328-uart1-olimex.dtbo rk3328-uart1-olimex.dts
added mine in the file /boot/armbianEnv.txt
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fdt_overlays=rockchip-rk3328-uart1-olimex
instead of the standard one that was
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fdt_overlays=rockchip-rk3328-uart1
but nothing...
various diagnostic commands returns always the same result
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ls /sys/firmware/devicetree/base | grep serial@
output:
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serial@ff110000
serial@ff120000
serial@ff130000
executed:
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cat /sys/firmware/devicetree/base/serial@ff120000/status
Output: disabled
Instead
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cat /sys/firmware/devicetree/base/serial@ff130000/status
give me the result okay (I suppose that this is the serial console uart, tested and working)
The command
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dmesg | grep ttyS
return always
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[ 0.000000] Kernel command line: root=UUID=3440d0ff-bb26-49a0-92cb-65352124c942 rootwait rootfstype=ext4 splash=verbose console=ttyS2,1500000 consoleblank=0 loglevel=1 ubootpart=ec32f700-01 usb-storage.quirks=0x2537:0x1066:u,0x2537:0x1068:u cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory
[ 0.865993] printk: console [ttyS2] disabled
[ 0.866687] ff130000.serial: ttyS2 at MMIO 0xff130000 (irq = 21, base_baud = 1500000) is a 16550A
[ 0.866814] printk: console [ttyS2] enabled
[ 6.976456] systemd[1]: Expecting device dev-ttyS2.device - /dev/ttyS2...
[ 9.592381] systemd[1]: Found device dev-ttyS2.device - /dev/ttyS2.
Output shows only ff130000.serial: ttyS2 (console/debug).
Despite these attempts, /dev/ttyS* does not show UART1, and the status of serial@ff120000 remains disabled.
Could you please confirm:
Which node corresponds to UART1 on the Olimex RK3328 SOM?
The correct pinmux/function settings for GPIO3_A4 (TX) and GPIO3_A6 (RX) for UART1.
Any known issues or additional steps needed to enable UART1 under Armbian?
Thank you very much for your help!
#93
NXP / Re: 1-Wire and 1.8 V on GPIO o...
Last post by LubOlimex - August 29, 2025, 10:25:04 AMThe pins at the UEXT of iMX8MPLUS-SOM-EVB are at 3.3V. We used translators for SPI and UART and transistors for I2C. Find the UEXT and look to the left to find the translators. If you decide to use GPIO1 pins (which are 1.8V levels) you can use the same translator SN74LVC2T45DCUR(VSSOP-8) to set them to 3.3V, use our usage as template on how we attached them to the signals of the UEXT.
These 8 pins can be used as GPIOs, according to the datasheet of the main chip they can be configured for GPIO usage. The pin #1 and pin #2 of UEXT are the power pins.
Notice that some of the pins at UEXT are inputs other outputs, there are pull ups, etc. This can be inspected in the EVB schematic again.
These 8 pins can be used as GPIOs, according to the datasheet of the main chip they can be configured for GPIO usage. The pin #1 and pin #2 of UEXT are the power pins.
Notice that some of the pins at UEXT are inputs other outputs, there are pull ups, etc. This can be inspected in the EVB schematic again.
#94
MSP430 / Re: MSP430-JTAG-TINY-V2 Window...
Last post by bcsmmc - August 28, 2025, 05:30:19 PMYou have to boot into the Troubleshooting screen, which means you need the bitlocker key and use option 7 to disable driver enforcement. Not sure about monthly updates, but you have to reinstall after a feature update.
1. Press the Windows key to launch the Start menu, click on the Power icon, press and hold the Shift key, and then click on Restart to enter the recovery mode in Windows 11.
2. Once the OS enters the recovery environment, click on Troubleshoot.
3. Next, click Advanced options.
4. Select Startup settings from the six options listed here.
5. Now, click on the Restart button.
6. If you are asked to enter the BitLocker recovery key, find out what to do. With the feature enabled, Windows may ask you to provide the key to ensure that no one else is accessing the data.
7. Finally, press the F7 or 7 key to boot Windows with the Driver Signature Enforcement feature disabled.
Once the system restarts, Driver Signature Enforcement will be disabled in Windows 11. You can now install the desired unsigned driver on your PC. To enable Driver Signature Enforcement in Windows 11, restart the computer.
1. Press the Windows key to launch the Start menu, click on the Power icon, press and hold the Shift key, and then click on Restart to enter the recovery mode in Windows 11.
2. Once the OS enters the recovery environment, click on Troubleshoot.
3. Next, click Advanced options.
4. Select Startup settings from the six options listed here.
5. Now, click on the Restart button.
6. If you are asked to enter the BitLocker recovery key, find out what to do. With the feature enabled, Windows may ask you to provide the key to ensure that no one else is accessing the data.
7. Finally, press the F7 or 7 key to boot Windows with the Driver Signature Enforcement feature disabled.
Once the system restarts, Driver Signature Enforcement will be disabled in Windows 11. You can now install the desired unsigned driver on your PC. To enable Driver Signature Enforcement in Windows 11, restart the computer.
#95
NXP / 1-Wire and 1.8 V on GPIO of iM...
Last post by ilario - August 28, 2025, 04:35:36 PMI am planning to use a iMX8MP-SOM-4GB-IND + iMX8MP-SOM-EVB-IND for replacing the A64-OLinuXino and having a modern Debian version.
With the A64-OLinuXino, I was using the GPIO for reading a few DS18B20 thermometers via 1-wire. I described what I am doing here: https://www.olimex.com/forum/index.php?topic=9266.0
The question is whether it is possible to do the same with the iMX8MP board as "Almost all signals have got voltage level of 1.8V!".
According to the DS18B20 datasheet, 1.8 V is not enough.
Do you have idea if using 1-wire will be possible?
Is there any GPIO pin I can use that already has 3.3 V or 5 V?
If all GPIOs are at 1.8 V, can you recommend me a level shifter from 1.8 V to 3.3 or 5 V?
With the A64-OLinuXino, I was using the GPIO for reading a few DS18B20 thermometers via 1-wire. I described what I am doing here: https://www.olimex.com/forum/index.php?topic=9266.0
The question is whether it is possible to do the same with the iMX8MP board as "Almost all signals have got voltage level of 1.8V!".
According to the DS18B20 datasheet, 1.8 V is not enough.
Do you have idea if using 1-wire will be possible?
Is there any GPIO pin I can use that already has 3.3 V or 5 V?
If all GPIOs are at 1.8 V, can you recommend me a level shifter from 1.8 V to 3.3 or 5 V?
#96
A64 / Re: 1-wire connection to DS18B...
Last post by ilario - August 28, 2025, 04:31:45 PMI added some guide at this page: https://linux-sunxi.org/1-Wire#Device_Tree
#97
New Products release / Re: PICO2-XXL with RP2350 and ...
Last post by LubOlimex - August 27, 2025, 09:22:21 AMEach board passed SD card test empirically here, we used CircuitPython. It is probably a software issue.
I see your defines are for 1-bit MMC but I am not sure if that demo supports 1-bit MMC data mode. In hardware revision A of RP2350-PICO2-XXL the SD card was configured in 1-bit MMC data mode by default. If you can't find properly working Arduino demo for 1-bit MMC mode, maybe consider configuring the board for SPI mode instead (since SPI mode is better supported by the software). You can populate resistor R24 to enable SPI mode, refer to the revision A schematic here:
https://github.com/OLIMEX/RP2350-PICO2-XXL/blob/main/HARDWARE/RP2350-PICO2-XXL-Rev.A/RP2350-PICO2-XXL_Rev_A.pdf
One thing to consider is that HDMI's HSTX also uses GPIO12 so there would be a conflict using HDMI and SD card at the same time.
Notice that in newest hardware revision B of RP2350-PICO2-XXL this was changed and the SD card is by default configured for SPI mode. Also GPIO12 was changed to GPIO24 to avoid the conflict with HDMI. Boards purchased from us are guaranteed to be hardware revision B.
I see your defines are for 1-bit MMC but I am not sure if that demo supports 1-bit MMC data mode. In hardware revision A of RP2350-PICO2-XXL the SD card was configured in 1-bit MMC data mode by default. If you can't find properly working Arduino demo for 1-bit MMC mode, maybe consider configuring the board for SPI mode instead (since SPI mode is better supported by the software). You can populate resistor R24 to enable SPI mode, refer to the revision A schematic here:
https://github.com/OLIMEX/RP2350-PICO2-XXL/blob/main/HARDWARE/RP2350-PICO2-XXL-Rev.A/RP2350-PICO2-XXL_Rev_A.pdf
One thing to consider is that HDMI's HSTX also uses GPIO12 so there would be a conflict using HDMI and SD card at the same time.
Notice that in newest hardware revision B of RP2350-PICO2-XXL this was changed and the SD card is by default configured for SPI mode. Also GPIO12 was changed to GPIO24 to avoid the conflict with HDMI. Boards purchased from us are guaranteed to be hardware revision B.
#98
New Products release / Re: PICO2-XXL with RP2350 and ...
Last post by geerten - August 26, 2025, 07:05:30 PMI have a couple of XXL's (Rev. A) and today I started to have a look at the SD-card slot.
In Arduino IDE, I found some examples (e.g. cardinfo.ino) for SD from the Earle Philhower libraries, but I couldn't get it working.
Closest I get is by setting:
const int RP_CLK_GPIO = 10; // Set to CLK GPIO
const int RP_CMD_GPIO = 11; // Set to CMD GPIO
const int RP_DAT0_GPIO = 12; // Set to DAT0 GPIO
With no card inserted this results in:
Initializing SD card...
initialization failed. Things to check:
* is a card inserted?
* is your wiring correct?
* did you change the chipSelect pin to match your shield or module?
And with a card it says:
Initializing SD card...
crc: EEE1F0111EEFF
chk: EEEEEEFFEFFFEEFF
initialization failed. Things to check:
* is a card inserted?
* is your wiring correct?
* did you change the chipSelect pin to match your shield or module?
Does anyone know how to fix this? Or maybe another example that will get me started?
In Arduino IDE, I found some examples (e.g. cardinfo.ino) for SD from the Earle Philhower libraries, but I couldn't get it working.
Closest I get is by setting:
const int RP_CLK_GPIO = 10; // Set to CLK GPIO
const int RP_CMD_GPIO = 11; // Set to CMD GPIO
const int RP_DAT0_GPIO = 12; // Set to DAT0 GPIO
With no card inserted this results in:
Initializing SD card...
initialization failed. Things to check:
* is a card inserted?
* is your wiring correct?
* did you change the chipSelect pin to match your shield or module?
And with a card it says:
Initializing SD card...
crc: EEE1F0111EEFF
chk: EEEEEEFFEFFFEEFF
initialization failed. Things to check:
* is a card inserted?
* is your wiring correct?
* did you change the chipSelect pin to match your shield or module?
Does anyone know how to fix this? Or maybe another example that will get me started?
#99
New Products release / ESP32-C5-EVB
Last post by olimex - August 26, 2025, 12:06:10 PMNew Open Source Hardware 2.4Ghz/5Ghz WiFi6, Bluetooth 5LE, Zigbee, Thread Development board with ESP32-C5 8MB Flash, 4MB RAM development board with Relays, Optoisolated inputs, LiPo battery UPS is available for pre-order for only EUR 16.95/ea. https://olimex.wordpress.com/2025/08/26/meet-the-esp32-c5-evb-open-source-hardware-dual-band-2-4ghz-and-5ghz-wi-fi6-development-board-with-built-in-relays-opto-isolated-inputs-and-lipo-ups-support/ #esp32c5 #iot #zigbee #thread #matter #esp32 #espressif
#100
PCB TECH / Re: BB-RELAY3-12V and BB-RELAY...
Last post by ilario - August 25, 2025, 04:55:43 PMVery clear, thanks!