Posts by a_px

Thanks. I obtained one of these which seems to do the job: https://uk.rs-online.com/web/p/car-chargers/2431658

I'm also using an OpenUPS2 device in the power line. This takes care of engine crank and eco engine cut-out events, but passes the voltage straight through otherwise. https://www.mini-box.com/OpenUPS2

Hi, thanks for the reply. The reason is I am intending to use this in a vehicle application and the vehicle voltage is likely to vary from 11 to 17 volts. With similar applications I have used vehicle laptop supplies to stabilize the voltage, but in general these have an output range of 15-21v. I will try to find a 12v device.

Thanks,

Alan

Hi, what is the input supply voltage range for the APU4D4? The spec says 12 volts, but does not specify a range. If I supply 15v will it fry the board?

Thanks,

Alan

Great, thanks!

Hi, is it possible to address the onboard piezo buzzer on a APU4D4 from within the OS? Alternatively, are there any GPIO pins that could be used to add an external piezo buzzer?

Thanks,

Alan

Hi mkopec

That's great, thanks. All working now.

Alan

I am attempting to enable 3 x mPCIe LTE modems using a APU4D4 board running Ubuntu 20.04.

I am aware the SIM slots relate to mPCI slots 2 and 3. I have fitted a SIM carrier to one of the LTE modems in slot 1 and this appears to work. The modem in slot 2 also works and I can query the devices via the USB serial ports that appear in /dev

However, although the activity LED lights up for the modem in slot 3, I do not see any USB serial ports appearing in /dev for this device and so cannot connect to it. Swapping the modems results in the same issue with no connectivity to the device in slot 3. If I remove the device in slot 3 and place it in an external USB carrier plugged into one of the external USB ports, I can then get all 3 devices to work.

Is there something I need to do with this slot position (3) in order to enable mPCI functionality as opposed to mSATA? The modem is powered and operating but I don't get any USB connectivity with it when it's in this slot.

1) The operating system is installed on the SD card, so I don’t need SATA/mSATA

2) The modems are Simcom SIM7600G-H (1e0e:9001)

3) The Qualcomm Option driver is installed for these modems

Thanks Alan