Recent posts

#1

New Product Ideas / Re: could you provide a random...

Last post by LubOlimex - October 17, 2025, 10:27:13 AM

MOD-MP3-X-LITE can not work in stand-alone mode. It lacks a main microcontroller.

MOD-MP3-X can work in stand-alone mode since it has STM32F103 on-board. The firmware of STM32F103 can be modified via ARM JTAG tool. The random function can be added if you modify the firmware, and specifically mp3PlayerTask.c and if you add a command to switch between random mode and regular mode, you'd also have to add it in uartUserInterface.c and uartUserInterface.h.

#2

NXP / Re: RTC for iMX8MP-SOM-EVB-IND

Last post by LubOlimex - October 17, 2025, 09:59:44 AM

I can see we that we use PCA9450 which one of the recommended by NXP power management chips. It has own quartz, so as long as the PCA9450 is powered it should keep the RTC alive. Also all connection are proper even the lowest power mode is properly connected (SNVS mode). PCA9450 has seven different operating modes (controlled by the input voltage on the VSYS pin and an external control signal (I2C that I inspected is connected between the main chip, the PMU, and the EEPROM).

The PCA9450 doesn't operate on battery tho. It requires 5V DC and from those it makes LDO1 and LDO2. And then if you seek lower power mode, configure the PMU for SNVS mode via the I2C. Refer to these documents:

https://www.nxp.com/docs/en/application-note/AN14246.pdf
https://www.nxp.com/docs/en/data-sheet/PCA9450.pdf

Notice that you can also check what the official NXP forums say since the board uses iMX8 and NXP PMU PCA9450C which is a recommended combo and NXP staff can also provide some insight.

#3

NXP / Re: RTC for iMX8MP-SOM-EVB-IND

Last post by LubOlimex - October 17, 2025, 09:06:16 AM

I have to check about built in RTC of iMX8, but using external module like MOD-RTC2 is not very hard as long the I2C communication is properly working. MOD-RTC2 uses a battery to keep the time and I2C for communication and when board get powered on you update system clock from the I2C, there is a demo for A20 board take a look:

https://github.com/OLIMEX/OLINUXINO/tree/master/SOFTWARE/A20/A20-OLinuXino-Micro%20with%20MOD-RTC2

#4

NXP / Re: Case for iMX8MP-SOM-EVB-IN...

Last post by ilario - October 16, 2025, 01:56:26 PM

It would be good to add it to https://github.com/hominoids/SBC_Model_Framework so cases could be generated for printing

Thanks for sharing that project, seems very convenient!
I started drafting the shape using the parameters from the Olimex's documentation, but surely I got plenty of dimensions wrong as I still don't have the actual hardware in my hands.
Feel free to correct the data I am preparing here:
https://github.com/hominoids/SBC_Model_Framework/compare/main...ilario:SBC_Model_Framework:Olimex-iMX8MP-SOM

#5

ESP32 / Re: ESP32-H2-DevKit-Lipo - Bat...

Last post by LubOlimex - October 16, 2025, 10:47:28 AM

Notice that when you have both USB and a battery attached, the battery measurement will not be correct, it will be influenced by the battery charger. The battery measurement is only correct when there is only battery powering the board. Hence it is helpful to utilize the External Power Sense and only measure the battery when there is no external power applied.

#6

ESP32 / Re: ESP32-H2-DevKit-Lipo - Bat...

Last post by lmerckx - October 15, 2025, 09:02:59 PM

Thanks for the answer.
I will try a longer charge and check values.

Thanks.

#7

New Product Ideas / could you provide a random pla...

Last post by APS - October 15, 2025, 12:16:44 AM

I use it as a standalone mp3 player, works great.  I would like to have a random play function.  I use it like listening to a great FM radio station that always plays the music you like and has no commercials.
alan

#8

ESP32 / Re: ESP32-H2-DevKit-Lipo - Bat...

Last post by LubOlimex - October 14, 2025, 04:31:50 PM

Seems fine to me. It just takes a lot of time to fully charge and discharge. The board is set to charge with only 100mA. Let it charge for a couple of hours and compare the value again. The JA-803450P should go up to 4.2V when fully charged. Alternatively let your software run only on battery and check the progress without connecting the USB to it.

#9

New Products release / OpenFest 2025 is this weekend ...

Last post by olimex - October 14, 2025, 12:10:37 PM

Join us this Saturday at OpenFest 2025 in Sofia for the traditional soldering workshop https://olimex.wordpress.com/2025/10/14/openfest-2025-is-this-weekend-in-sofia-come-and-join-us-in-saturday-at-the-traditional-soldering-workhop/ #openfest #soldering #workshop #oshw #foss

#10

NXP / RTC for iMX8MP-SOM-EVB-IND

Last post by ilario - October 13, 2025, 11:37:25 AM

On A64-OLinuXino there was an exposed contact for adding an external battery powering the Real Time Clock present on the board, as explained here, and it was very useful.

Is there something like this for the iMX8MP-SOM-EVB-IND?

Maybe using a UEXT module like the MOD-RTC2? But then, how should one use it? Should one write a Systemd unit probing the RTC and updating the system time? Is there something like that ready to use?