OY!

[L67GS]

Pulled the trigger and ordered an XU4 -w- eMMC 5.1 Blue Dot, shifter, VU7A Plus, Rii i8+ Keyboard / trackball combo just last night!

I've been programming microcontrollers for a couple years with LdMicro and have a background in electronics spanning decades so the cute little SBCs that are little more than a Microcontroller on a breakout board fail to excite me.
I suppose by definition I'm a "Maker", electronics both for fun and work are things I do start to finish, "Fixing" doesn't turn me on at all and I only fix out of necessity.
I played with Nextion enhanced for a while and it's a really cool little HMI, in conjunction with a microcontroller or two they're fairly dangerous but still not incredibly powerful since it's still a HMI by definition
Last year I took my second run at C++, it's incredibly boring since the learning process isn't exactly real world interactive so I've been learning slowly. I feel good about the XU4, reading the specs gets my blood pressure up and I'm foaming at the mouth already in anticipation of making those IO ports do something so hopefully it's the right teaching aid for me and I can finally make that leap to C, C++ developer I've been wanting to take.
When I ordered the Blue dot was a no brainer as a 20 year Linux user, but I have concerns now about the touchscreen since there's a few threads about issues in Linux and I didn't see any threads praising the use of the VU7A in Linux. I got the Shifter board to put the IO pins into the realm of what I consider "useful" but I'm still intrigued with the manufacturers decision to make them 1.8V native... Looking forward to learning what people do with a <2V IO, and much more here.

[mad_ady]

VU7+ works great under linux, but I guess most people who use vu7 use android.

Regarding xu4 pins - yes, they are a pain to work with (small pith, low voltage), but xu4 has the best software support. Samsung made the soc low voltage because it was meant for phones...

Regarding C++ - you need to find a project that motivates you to use the language, that's all...

[L67GS]

Thank You, I feel a lot better about the VU7+ now!
The explanation for the IO voltage makes a lot of sense, and to add to it: it's safe to assume they didn't "shift" them up onboard because of space constraints. I suppose board layout was a factor in their decision not to stay with the "C" form factor when they made the XU4? At least it makes sense to me anyway.

[mad_ady]

Size was important for xu4 because it's a 10 layer board. Also the extra cost to shift it up may not have been beneficial since most users don't use the pins...

[L67GS]

Oh yeah, I noticed that, it looks like a good deal of users are building them into media servers and game consoles.
Ultimately I'd like to turn this into a carputer. Originally I was going to run a 7" Nextion but the XU4 should do everything a HMI does as well as everything audio and GPS.
I'm in the middle of a set of custom LED gauges right now, the headlight switch is a Nextion 3.5", and my odometer is a red on black LCD. I've been hung on the speedometer for a while so I should get back on it.
Are you a maker? What kind of projects?

[mad_ady]

I'm not that skilled with making hardware stuff. I'm mostly playing with software/network...

[L67GS]

A little bummed out, I thought it would be here by the weekend but it's not.
Can somebody recommend a thread that outlines GPIO control with C++ or Linux command line so I can write some preemptive code and have fun?

[rooted]

C/C++
https://wiki.odroid.com/odroid-xu4/appl ... o/wiringpi

Command line
https://wiki.odroid.com/odroid-xu4/appl ... ent_30pins

[L67GS]

Thanks odroid!
It almost looks like it might be easier to issue std::system commands and sysfs than wiringpi. I'm anxious to see.

[mad_ady]

The difference will be switching performance. sysfs is orders of magnitude slower than wiringpi. But if you want to toggle the pins 10s of times per second, sysfs should be ok.

[L67GS]

I already started writing a little test program, if it turns out useful I'll post it.
Has anyone else posted a little doodle program to just swith GPIOs on/off, send data, or pwm for proof of concepts? Or just those sample codes...

[L67GS]

I think I understand the C++ io control. Correct me if I'm wrong.
pinmode (pin#, direction)

The man page is a bit vague, but if I understand the usage the following code should work:

//Odroid XU4 GPIO syntax test

Code: Select all

#include <iostream>
#include <wiringPi.h>
int main (){
   wiringPiSetup();
     // Define pin 1 as output, 2 as input
    pinmode(1, OUTPUT);
    pinmode(2, INPUT);
       // Pull pin 1 high 
        digitalwrite(1, HIGH);
             // query pin2 state
                if (digitalread(2, LOW){
                    std::cout << "Pin 2 is low\n";
                     }
}

[mad_ady]

That looks ok/reasonable...

[L67GS]

Oh cool! Thank You...

I think what I'm going to do is work on GPIO when it arrives, then start a thread in the Ubuntu subforum specifically for matters of C++ XU4 GPIO since I didn't see such a thread when I was looking.
I'd like to cover I/O, UART, and PWM so it's documented and then hopefully as other people chime in it will include SPI and I2C.
I'm not particularly interested in SPI and I2C but I'm very interested in UART since I've already been through it with LdMicro and Nextion.
BTW, I'm aware PWM isn't an option on XU4 so I'll be using UART to send a value to a PIC16F and doing PWM out of that. I'll zip up the HEX file and pinout when it's appropriate and share it in case anyone else wants it.
Right now I have a nifty output expander that takes 4 GPIO pins from the control device and uses them as binary lines, the PIC16F886 I programmed it for provides 15 output pins in exchange for the 4 IO pins on the control device. It's one way though, no input to the master device. Of course data transmission is more efficient but it was a neat little project and at the time I wanted to use Nextion as my HMI and because of the stop bits it threw LdMicro for a loop.

[L67GS]

It came yesterday, I spent the evening doing updates and installations. I ordered a Bluetooth adapter with it and it wasn't recognized by the XU4 or either one of my computers. I tried to run a couple of C++ programs I've written on it and the compiler kept failing because it couldn't get past std so I reinstalled gcc, no good still.
Then I uninstalled some items that I knew I'd never use like email and Onboard started acting erratic.
I figured at least I could have the experience of reloading so I snapped the eMMC into the adapter and it doesn't work on either of my computers.
Not off to the best start, I will say my fan is so quiet I can barely hear it running, here I thought pwm motor whine was going to be the biggest problem but ameridroid sent me 2 DOA items, lol.

[mad_ady]

You should open a new thread for your issues.
For the BT device - do you see it in dmesg when you plug it in? Does it show up in lsusb? Have you tried the usb2 port as well?

For the EMMC - what adapter are you using ? the one to microsd? Are you using a microsd-to-sd adapter with it? Those might be flaky...

[L67GS]

I didn't get too involved diagnosing the Bluetooth adapter, it's not recognized by any computer. Ironically after I ordered it my old Bluetooth adapter resurfaced so I'm still in business there.
The eMMC adapter is that little chunk of circuit board that goes into an sd reader, I still have one SD reader to try tonight.
I clipped some safety pins to my meter leads and lit the plug out, continuity from each pin to the pad on the board so hopefully it's just picky about the reader.
I'm unsure how I feel about not having Onboard, my wireless keyboard/pointer should be here by tomorrow but not being able to compile is a problem.

[Ameridroid]

eMMCs are pretty picky about the reader. Make sure you are using a high-quality microSD reader/writer. Avoid using microSD to full-size SD adapters as they are often the cause of problems. All the eMMCs are tested by the manufacturer before shipping.

Regarding the BT adapter, if you have one that works and the one you bought does not, it is probably faulty and we can send you a new one. If that is the case, send us a message via https://ameridroid.com/pages/contact and we'll take care of it.

[L67GS]

Thank you Ameridroid, I tried my last remaining SD adapter and it works! Oddly enough the one that works is a mimi to full size adapter stuck in the onboard card reader on my Laptop.
The BT adapter is still non functional, but I do indeed have another that works. I did send a message from your website this morning so I'll look for instructions on sending this one back for exchange if I don't get a call.
i'll be ordering a bigger eMMC soon and likely an N2 at some point.

[L67GS]

Ameridroid if you see this I just sent out that Bluetooth dongle for RMA replacement, I sent a message on your website but it would be cool if you could hold my order for the 128 GB module I ordered last night and toss the Bluetooth adapter in the same package once my RMA arrives. It's going to be awhile before I outgrow my 8GB.

[Ameridroid]

L657GS - Caught it right as it was leaving. Didn't want to hold up your order so just slipped it in with the 128GB eMMC.

Have a great weekend!

-Bo

[L67GS]

Thank You, I"m not in a terrible hurry for the eMMC but now that I found my old adapter the luxury of shooting cpp files between myXU4 and big PC sounds nice.

[L67GS]

Wow, I didn't think there was a dire need for that BT dongle but tonight blasting .cpp files back and forth between computers instead of trying to get my fingers at the sd card is awesome! Thank you.

[mad_ady]

You know, you can use regular networking for file transfer...

[L67GS]

Lol, I do a lot of stuff in my electronics lab at work after hours. Where I am there's no internet so there's no router or anything.
For sending large files I'd come up with a plan B but small stuff like a .cpp file is across Bluetooth instantly in a few clicks.
I'm thinking about trying remote desktop over Bluetooth next just to see if it works.

[mad_ady]

BT bandwidth is very small, so vnc will suffer.

[L67GS]

I ordered my next Odroid product already, a CO with sound board, 3000 mah battery, usb microphone, power supply, 128 gb eMMC, connector pack, heatsink, HDMI / vga adapter, and a little audio amp.

Can't wait to see how it compares to the XU4.

[mad_ady]

Can't wait to see how it compares to the XU4.

Spoiler alert: poorly

[L67GS]

Lol, I know I have an embedded project I thinkit will be a good fit for. In the end it should end up headless and running command line with no IDE even installed.
I am excited to get that battery fully charged and see how long it'll run on it.

[L67GS]

The C0 is sooo freaking awesome with the HIFI shield, I really wasn't expecting the shield to line up so perfectly and it really blew me away to see the notch for the GPIO plug.
I still haven't powered it up yet (have to solder the headers on it at work tomorrow) I'm curious how the HIFI shield is going to sit with the dual USB, the clearance is just right for the heatsink I got from Ameridroid and would be enough clearance for the single USB but I want the dual. Hopefully I have a female header in my lab the right pitch so I can just pop some bus wire jumpers between the C0 and shield. No standoffs come with the HIFI shield (my XU4 shifter came with them, and an extra) so I'll scavenge something or use screws and nuts with plastic tubing spacers.
In all I'm excited to do some testing tomorrow, and looking forward to having two Odroid SBCs to learn with.

Edit: A couple quick questions, eMMC cards are all "physically" the same, right? So there's no reason I can't put an Android image for C0 on my spare card for my XU4 and try Android on the C0?
Also, the HIFI shield doesn't work in Android, but it's available in HDMI if I break it out with a vga/audio cable, right?

[mad_ady]

Emmcs are not identical. Note that the old "Black" emmc will not boot on XU4. The orange emmcs need updated kernels to be recognized on some boards. But otherwise yes - you can use a XU4 emmc on C0 provided that you flash the correct image to it.
The hifi shield doesn't have Android drivers, but you can use a HDMI splitter to extract audio from HDMI (but you don't need the Hifi Shield for this).

[L67GS]

I was mistaken, the Hi-Fi Shield did indeed come with standoffs. They were stuffed in the end of the little box and I didn't notice them until I gave it a good Shake. I'm curious why the resolution is set so high on this thing, I can barely read it and there's only one option to select so I'm going to have to figure that out before I can really do anything with it.

[L67GS]

Looking back on this thread from WAY BACK ...... two months ago, I just ordered a second C0, a C1+, and some misc stuff. Intrigue with the XU4 just 2 months ago has rather quickly brought me to the point of owning 4 Odroid SBCs and a sizeable pile of accessories in such a short time. I absolutely expect to acquire at least a third C0 before product discontinuation just so I have it unless Hardkernel announces a replacement with a similar whoop ass to efficiency ratio. If only I'd noticed the 128 eMMC cards were circling the drain in time, only got 2 of them, but thankful to have them.

[mad_ady]

Obvious signs of an untreated addiction. Welcome to the club!