EM9190: Suggested Adapter?

I am at a loss. Trying to use the EM9190 module as a home gateway. I am trying to install the module on a BananaPi-R64. The mainboard has a secondary MPCIE 2.0 port available in addition to the primary MPCIE slot which I am using for my wifi AP card (MT7915), as well as a USB 3.0 port available.

Prior to this tinkering mainboard, I always used an MC7455 on a PCIE-to-USB bridge on a branded router flashed with OpenWRT, and assumed I take the same approach. Bought an M.2 to USB 3.0 adapter, and the device refuses to boot in both Linux and Windows. Went to the vendor for assistance, and was directed to purchase a dev kit or come here for pointers. Looking for any way possible to avoid buying a $750+ dev kit to configure the $400 module I just purchased. I honestly just need to get this module to switch over to USB mode…

I’m searching for either a USB 3.0 adapter which will provide the additional functionality of the additional pins required to initiate the switch to USB mode, or any suggestions on a M.2 to Mini PCIE adapter that offers a SIM slot.

Any help or a point in the right direction would be highly appreciated. Please.

Hi @JoeBurman19871,

It is unlikely to function properly with a converter off the internet as some of the pins will almost certainly be configured incorrectly which will cause the unit to not power up or not be detected correctly.
So you cannot use an adaptor with the unit, you either need to use a specifically designed board or dev kit which is designed for EM9190.
(You can refer in this ticket: https://forum.sierrawireless.com/t/em9190-not-being-detected-in-windows-10/21405.)
I think you should contact your distributor and purchase a devkit for your EM9190.

Thanks,

Thank you for the reply. Would this device work with an M.2 to Mini PCIe adapter? I do have an available on-board Mini PCIe slot.

Hi @JoeBurman19871,

I am not sure this device can work with an M.2 to Mini PCIe adapter. I still think you should use a specifically designed board for EM9190 that is provided by the contributor to avoid unworthy issues.

Thanks,

An M.2 to Mini PCIe did get the board to power up, and even show up in the system log! However, I have yet to get enough time to tinker with it further.

However, I can confirm that this adapter (https://www.amazon.com/gp/product/B08P1CTC6N/) works to power up the EM9190 on a BPI-R64 board.

Hi @JoeBurman19871 ,

we are using the module on an PCIe slot with an M.2 adaptor. You’ll need to ensure proper cooling of the module, we had issues with that when using 5G.

Best regards
Carsten

Yes, heat dissipation was a big concern before starting. My MC7455 liked to get quite toasty and I figured the increased power consumption and data rates of the EM91 series would be problematic for heat buildup.

I put my entire project in a small project box with a Noctua 120mm fan pulling air through the enclosure. Sounds like a damn turbine and is probably overkill, but I’d rather be safe than sorry.

I got an EM9191 working using this PCIe adapter: https://amazon.com/dp/B08PD2D4RZ

I made some modifications as shown in this picture. The resistors have the same value, and function as a voltage divider to provide a suitable voltage for Pin 20 (PCIE_DIS). I should probably have used a resistor between Pin 2 (VCC) and Pin 22 (VBUS_SENSE, enables USB), but I just ran a wire.

Please ignore the large loop. I was going to use a shorter wire, but I saw no benefit in shortening it once it was soldered and working. I just taped it down and called it good.

I’ve used this adapter with an EM7565 for years with no issues: https://ltefix.com/shop/pcie-m-2/m-2-ngff/usb3-to-ngff-m-2-key-b-3050-5g-adapter-enclosure-with-sim-card-slot/

I’ve used that one as well, but the EM9191/EM9190 require specific signals to disable PCIe and enable USB. It works fine with an EM7565, but needs modifications to work with the EM9190.

Hi @cgrascher

Regarding the PCIe-to-M2 adapter which worked with the EM9191:

Was it working in PCIe mode?

If it was working in PCIe mode, do you know whether the computer motherboard supported PCIe Gen 3 speed?

There is the following statement in the EM919x Product Technical Spec at the beginning of section 3.4: “Note: Host support for PCIe 3.0 signals is required when PCIe is selected as host interface.” (It seems strange to me that PCIe mode may not work in PCIe mode with a computer motherboard which supports only PCIe Gen 2.).

Or was it working in USB2 mode with rework added to the adapter to pull up the voltage on Pin 20 (PCIE_DIS)?

Thank you.

Hi @Vaughn.Sheline ,

it is working in PCI mode, and our platform has PCIe Gen 3 (but no USB).

We are using this adapter: Delock Products 63384 Converter Mini PCIe > M.2 Key B slot + Micro SIM slot

Regards
Carsten

I finally found an adapter that you can buy off-the-shelf that will allow this to work via USB! This is the ONLY one I’ve found. If you look at the block diagram of it, found on the documentation on their website, it says that they connected a pull-up resistor to pin #20 (PCIE_DIS) which sets the pin to high (1.8V), enables the USB interface, and disables the PCIe interface.

http://www.hwtools.net/Adapter/UN32A.html#Web-shop

I recommend this adapter , Dual-Q M2-USB3 Dev kit MH2U V2 design for Sierra wireless EM919x Telit FN980 Thales MV31 – 4G discount . this one design for EM919x and EM7690 , has switch to made modem switch to USB mode,