Power & Source of Big Ideas

This should work if you supply 5V to the board. All of my T3 designs work this way. No need for any buttons to press, just power on and they boot.
Use an SD card to flash the eMMC. Info on the wiki.
You need to build a custom OS image to include the phone and you need a suitable RIL for this to match with your modem. A USB modem is ideal as this has the multiple serial ports you need for SMS and AT commands etc. SIMCOM makes modems that work with the boards here and they have a RIL for them tha...
Wrong answer.
The OP asked how to add the phone app the Android build. By default, this is not added. You need to rebuild with the RIL etc.
I've not done any check of the OS build or the schematic but these sound like INPUTS.
From a quick look at this, there is no charging or way to have both external and battery at the same time without some kind of protection circuit. You'll need to do some additional external circuits to charge these too.
You can use eflasher to put the image onto an SD card and then this will write the image to the EMMC. This same method works for the T4 that I have.

http://wiki.friendlyarm.com/wiki/index. ... nd_SD_card
As I recall, eflasher is what you run on the Linux PC that you use to do the platform development and download to the NEO4. Fastboot is what you run on the NEO4 to put it into the correct mode for eflasher to work. Pretty sure I used this on the T4.
What baud rate did you use? It should be 1,500,000 which PUTTY can do. Some USB - Serial cannot support that speed but I have found that the CH340 does. The FA one uses this.
You need a TTL to USB serial adapter and PUTTY as the debug is a fast output of 1,500,000 bps.
Can you link me to the WiKi for your board as I cannot find the board you talk about.
What does the debug output show?
I downloaded the kernel and Android source this weekend to try and build an image with Realtek WiFi support for the Fire3 as that has no built in WiFi. In the wifi_bt.ml file I changed the build to Realtek but the Android source fails as it can't find the wlan.ko file. I searched the kernel source t...
Looking at the R2S schematic, the VDD_5V on the GPIO will allow you to power the board but put a fuse inline as there is no protection using that method.
Does the schematic show these pins as an INPUT or OUTPUT?
When you open the device in code, do you get a filehandle or -1?
Check the schematic to find out which GPIO pin it is connected to.
Do you have the correct permissions set in the .rc file?
Have you tried just connecting to HDMI without the LCD connected and see if you get anything?
What does the debug output show? That is the best way to know what has happened.
The baud rate is very high at 1,500,000 bps. Putty works.
eldridgek1975 wrote:
I have the SIMCOM SIM7600E-PCIE module working with the T4 under Android.

Which Android version? I have it working with 5 and 7 on a T3 but have the drivers for 8 but not yet tested it on the T4.
Hey there. Just moved overseas to Perth, Australia and in quarantine so I was not logged in on the laptop.

Thanks for checking up though, it is much appreciated.

I get out of quarantine on the 25th Feb and once I get to the new home, I'll be back on the main PC where all my code is.
The best solution for RF testing is with a spectrum analyser and come RF probes. They are cheap now compared to a few years ago.
Which OS are you using it with?

If Windows, what does device manager show?

If Linux, what does dmesg show?
That has an 8 bit SSD1963 so you'd need a driver and enough GPIO to use it. From what I can see, the Neo Air is a headless design only. There is no interface for video that would be plug-in. You might be able to get a small form factor SPI interfaced LCD to work but you'll need to find drivers etc. ...
Good day. If you follow the instructions from the integration manual, it is fairly simple to add to the OS build. You'll need a little experience of the OS build to know what files to change. Use the debug UART to monitor the radio debug (logcat -b radio) from the command line. This will indicate if...
The best way to do this is to build your own Android OS and set the SELINUX command line in the build.

You also need to set the tty ports in the init.rc to be accessible from the user space. Setting them to 0666 works for me. I also do this with the I2C and SPI etc.
Double click the file and then top right, choose download.
Be aware that changes to the I2C bus assignments might upset the system although most drivers do a probe to try and locate which bus they are present on.
Have you measured the voltage from the 5V supply?

That IC you refer to if labeled U110 is a regulator, MP2143DJ, and on pin 5 there should be 3.3V and pin 2 is the 5V input. This regulator is enabled by the PMIC.
It should be possible to swap them in software at the kernel level as they are allocated based on register settings. I don't even think you have access to the FriendlyCore Xenial source to do this. If the OS uses a device tree, you can swap them very easily by simply making changes to the tree. This...
Both I2C0 and I2C1 are available on the GPIO header so you should be able to make the software work but changing pins.

You have a serial cable to connect to the debug port? That is your best diagnostic tool for headless systems as you can see what is happening during the boot cycle, long before even HDMI output is enabled. Connect to the: Serial Debug Port: 2.54mm pitch 4-pin-header, 3V level, 1500000bps You'll need...
I did a design to use the T3 (same applied to T4) in a mobile application and used an ATTINY414 to handle the ignition detection and shutdown. The ATTiny was powered by the same 5V that powers the T3. Scenario 1. Ignition ON : The ATTiny reads the ignition status and if it detects that the input is ...
Hello again. The T4 GPIO Is easy to use from Android but you do need to ensure that you have user access to it and to do this, you need to add some settings to the .rc file to set the ownership and chmod for access. To do the power up and down via another GPIO Pin is not so easy but the power button...
The RIL is easy if you follow the instructions from SIMCOM. I think Android 8 is the current highest support. https://techship.com/downloads/simcom-3g-and-lte-4g-modules-android-ril-drivers-and-guide/ You'll need to register to download it. Good luck. Let me know how you get on with it. It needs to ...
Any GPIO pin should work. You just have to find the driver for whatever OS you plan to use.
The Ethernet pair is available via one of the GPIO headers but you will need an external magnetic and RJ45 connector to use it.
There is no Ethernet hardware on the NEO PI Air. The reference in the Wiki is likely from a copy and paste.

Wifi only.
I use a SIM7600E-PCIE module to provide a GSM connection and it also comes with a GPS as part of the module. Simcom offer various Android RIL for their modules and a GPS drive that hooks into the OS and instructions on how to build this into the OS. I've used this with 5.1 and 8.1 as they have not r...
To debug you connect to the header DBG UART on the edge of the board. With this you can see the debug output and also be able to type into this various linux commands as if you were using the terminal. Note that the baud rate is 1,500,000 bps so you will need the use Putty to read this. Any 3.3V TTL...
Connect a debug cable to the T4 and see what is showing up in the output. If you don't have one, get one, they are cheap and it will help to diagnose what is wrong. The other option is to create a bootable SD image and hold down the BOOT button so that is boots from the SD card. If this doesn't work...
What else is in that directory?

This is T4 Android 8.1 from Gitlab?

This is the same directory and math is also a directory within this. Does this match up with your directory structure?

https://gitlab.com/friendlyelec/rk3399- ... gle/common
Under my 8.1 source, math is a directory.

What is in the text file?
What is here?

opendir failed: external/guava/guava-gwt/test/com/google/common/math: Not a directory
Yeah, remove the code you added and rename that old file and then do a clean and then rebuild. That will get you back to a working system. By the way, why do you need this SU version? I have found that the T4 build already has SU so you can do root via the debug UART or through ADB SHELL commands. I...
The LED wasn't blinking before the problem started, and I have since changed the OS, SD card, and power, so the common denominator is the firmware, I believe. Is there something in the firmware that might have triggered this? Looking at the schematic, the LED is driven by a GPIO pin. If this is ON ...
The debug serial port is your best place to see what's happening during the bootup.
The M4 I think is the same baud rate as the T4 which is 1,500,000 so use something like Putty to connect to the debug port.

I got caught out with this same thing too.