STM32MP1-OLinuXino development update, we managed to build Ubuntu 18.04.LTS with Linux Kernel 5.3. Now we need your feedback on GPIOs

kit

One of the benefits to work with European SOC vendor and distributors – just few days after we show interest in the new STM32MP1 series of SOCs DHL come with one big carton where we got STM32MP151AAC and STM32MP157AAA3 samples plus the most comprehensive ST kit with all features of the high end STM32MP157AAA3. The credits go to EBV as we got these totally free of charge. The kit came with comprehensive documentation for both board, software support etc. In regard of customer friendliness Chinese SOC vendors has long way to go.

We needed one day to build our own Linux image as we didn’t like (no offense) the Yocto ST uses, so here is Ubuntu 18.04.LTS with Kernel 5.30 boot:

screen

Overall we have very positive vibes that STM32MP1 is good candidate for new industrial grade OLinuXino-LIME2!

The specs of the STM32MP1-OLinuXino-LIME2 we work now are:

  • STM32MP151AAC or STM32MP157AAA3 they are pin to pin compatible so one board will be used for both
  • 1GB DDR3L industrial grade memory -45+90C
  • Gigabit Ethernet with PoE plug-in option (*)
  • AXP209 PMU with LiPo charger and step-up so everything works even with no external power supply
  • two USB 2.0 high speed hosts
  • USB-OTG 2.0
  • HDMI+CEC
  • LIME2 board shape and same connector positions
  • replacing with CAN the SATA connector
  • micro SD-card
  • SPI/NAND/eMMC Flash on socket and different options(**)

(*) we love what Raspberry Pi did with their PoE hat, board which is working as normal, and have PoE functionality if PoE hat is attached. We intend to add such PoE feature to our other Allwinner boards too, but will take time to re-design them all.

(**) this is new experimental feature instead to keep many different LIME2 board versions which only differs the amount of flash on them. The Flash will be on plug in module, something which Odroid does for years and we do wonder why we didn’t do earlier, as now keeping so many versions of LIME, LIME2 and MICRO is killing our production manager and logistics :). If these Flash modules work as expected we will re-design our LIME, LIME2 and MICRO to use them also .

STM32MP1 series has some very unique features missing in Allwinner SOCs like:

  • 6× I2C up to 1 Mbit/s
  • 4× UART + 4× USART up to 12.5 Mbit/s, ISO7816, LIN, IrDA, SPI slave
  • 6× SPI 50 Mbit/s, 3 FD I2S audio class accuracy
  • 4× SAI stereo audio: I2S, PDM, SPDIF Tx
  • SPDIF Rx with 4 inputs
  • 8-14-bit camera interface up to 140 Mbyte/s
  • 2× ADCs with 16-bit max. resolution 3.6-4.5Msps
  • 2× 12-bit D/A converters 1 MHz

We will try to arrange GPIOs with similar functions so A20-LIME2 current customers to may exchange with STM32MP1-LIME2 if they want or to have second SOC choice, but we are open to listen to your tips and suggestions how to arrange the ADC/DAC signals and extra I2C, UARTS, SPIs on the GPIO1-GPIO4 connectors optimally.

STM32MP1 series has only one operating temperature range -45+125C.

Many people may think that on 650Mhz the Cortex-A7 cores are running slow, but this is because this SOC has to work reliable from -45 to +125C. All SOCs which run on extended temperature range run on lower speed clocks compared with same parts which run on commercial 0-70C. If you want to run your STM32MP1 board at home in non demanding apps, we are pretty sure you will be able to overclock it at much higher values and it will work, but when we talk industrial devices and reliable 24/7 operation the clocks are always announced with most conservative values.

The Open Source Hardware Linux board A20-OLinuXino-LIME2 is now supported by freedom respected Parabola GNU Linux-Libre distribution

Parabola_Gnu_Linux-libre_icon.svg

Parabola GNU Linux-libre is derived from Arch (the GNU/Linux distribution) and provides packages from it that meet the Free System Distribution Guidelines (FSDG) and replacements for the packages that don’t meet this requirement.

The goal is to provide a fully freedom-respecting GNU+Linux distribution.

We are very happy to announce that now A20-OLinuXino-LIME2 is one of the supported boards.

STM32MP1 nice candidate for new industrial grade OLinuXino-LIME

Screenshot from 2019-09-03 15-00-34

ST Microelectronic released new interesting device it’s Cortex-A7 and Cortex-M4 in one package. This solves two problems – the connectivity and ample amount of DDR3 memory to run Linux on Cortex-A7 core and the additional co-processor with Cortex-M4 for Real Time tasks. On top of this it’s -40+125C operating temperature and with 10 years supply longevity warranty from ST.

The prices starts around USD 5, which is in same range as Allwinner/Rockchip.

Their top model STM32MP157C has 3D openGL ES2.0 and CAN. There will be finally properly documented Secure boot (we hope 🙂  ):

Screenshot from 2019-09-03 15-06-23

From recent Twitter post I see than Bootlin already works on Linux support for STM32MP1.

Overall STM32MP1 looks like very promising SOC for Industrial grade Linux computer.

Magic shield plates helps naked A20-OLinuXino-LIME2 board to pass CE EMC requirements.

Ax0-OLinuXino-LIME-1

A20-OLinuXino-LIME and A20-OLinuXino-LIME2 are choice for many industrial applications, when the board is inside metal box like BOX-LIME:

BOX-LIME-BLACK-1

it has no problems with shielding the radio emissions, but when just board is used as component, our customers has to shield it by their own in their designs. We had number of request to do official CE EMC certifications for A20-OLinuXino-LIME2 as this would make their life easier, and we decided to do this after we already get some experience with the certification of USB-ISO and ESP32-POE-ISO.

Initially the naked board failed on EMC measurements as seen here from the test results.

LIME2-naked

The major problem is the Gigabit Ethernet PHY. You can see spikes at 125 Mhz, 325Mhz etc. Disabling the PHY removes all noise and everything is in safe levels. So we knew who is ther trouble maker.

The major noise emitter are the Transmit and Receive clock lines. We put 33 ohm resistors in series R119 and R123 in A20-OLinuXino-LIME2 schematic , but obviously this was not enough. To further fade the line harmonics we replaced the resistors with 0402 Ferite Beads with 600 ohm impedance at 100 Mhz. This lowered the emissions, but still not well enough to be at safe levels.

So we had to make small Faraday cage on top:

LIME2-SHIELD-top

and bottom of the board:

LIME2-SHIELD-bot

this effectively removed all noises and the A20-OLinuXino-LIME2 pass CE requirements:

LIME2-1

LIME2-2

LIME2-3

LIME2-4

We are preparing now to implement the Ferite Beads on PHY Tx and Rx lines in all our other boards production assembly, and will offer the shield plates as kit they are good for A20-OLinuXino-LIME and A20-OLinuXino-LIME2 and we will prepare same for A20-OLinuXino-MICRO and A64-OLinuXino.

 

New Debian 10 Buster images released for A20 and A64 boards and SOMs

buster

We have released Universal A20 and A64 images with Debian 10 Buster.

There are few known issues which we work on:

  • Certain types of eMMC memories might start in HS-200 mode instead of SDHS mode. This causes eMMC installation and boot problems.
  • HDMI always takes precendence over LCD. This is even if you have enabled a
    display manually (interrupted u-boot and executed “olinuxino monitor set XXX”).
  • Boards with 5.x eMMC chips are unable to boot directly from eMMC;
    this is caused by poor eMMC 5.x support in eGON BROM;
    this issue is not related to the Linux image
  • The board currently cannot store rootfs on usb driver. The init script
    starts before the usb subsystem initialization.
  • If the board has eMMC and SPI, it’s not possible to boot from SPI and rootfs
    on SATA. This is due to the fact that u-boot searches first the eMMC storage
    for boot scripts.
  • LCD-OLinuXino-15.6FHD is not fully supported.
  • The GT2005 camera module in A20-SOM-EVB and A20-SOM204-EVB is not working.

New release is preparing and will be updated by the end of the month.

 

 

New from our forum – experimental NixOS image for TERES DIY OSHW Laptop

nixos.png

Recent post from our forum explains how to build experimental NixOS image for TERES-I  – Do It Yourself, Environmental friendly, modular Open Source Hardware ARM Laptop.

Lime2-SD add on board for second SD card on A20-OLinuXino-LIME2

Lime2-SDa.jpg

Lime2-SD is small add on board which snaps on GPIO-1 connector and add second SD card to A20-OLinuxino-LIME2. It doesn’t interference with other parts on the board and do not increase the height.

Lime2-SD

Why we do this? Because this is an easy way to increase storage for Pioneer-FreedomBox-HSK . What we are preparing to offer soon is upgraded version of the Home Server Kit with 256GB storage made with 2 “disks” x 128GB micro SD cards. For these who already have Pioneer-FreedomBox-HSK they still can upgrade by ordering Lime2-SD .

Note that support in FreedomBox for Lime2-SD is not add, but you can try Lime2-SD with the current Armbian image for LIME2. To enable the Lime2-SD support you also have to add this dts overlay .

 

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