Allwinner V3X

# Picture above! [QQ picture 20220312200954.jpg] # 1. Introduction The chip used in this development board is Quanzhi's V3X, with built-in 128MB RAM and some other peripheral functions. I will not introduce the details. Please go to the pit network. Go search it, the information in it is more detailed. Attached is the link to the pit network: [pit network](https://whycan.com/) # 2. Before using the original intention, I open sourced an Allwinner V3S development board, and I have drawn two versions, one is a development board The form has been open sourced, and there is another method that uses a core board plus a baseboard. The core board has a MINI PCIE interface. This is mainly for the convenience of drawing the baseboard and DIY (not open source yet, but will be opened in the future). Why should I use the V3X chip? Mainly because I had a problem when running a QT application I made with V3s. Specifically, when I use V3S to run a QT application, every time I open an application, I run a comparison It freezes, which means it takes a long time to respond, and the usage effect is very poor, but sliding on the main interface is still very smooth, and the video playback effect is still good at 480x272 resolution. First of all, I suspect there are two possibilities. One is that the QT application written is not very good, causing lag in use, and the other is that the processor performance is not enough. It may be that the memory of V3S is too small and cannot bear it. When V3S was open sourced before, Brother Hao sent me a big red envelope and informed me that there was a V3X event. I didn’t apply because there was no demand before because the RAM of V3X is twice that of V3S. I just wanted to try out the running effect of V3X. It was better, so I went to Brother Hao to apply for two tablets of V3X. I am very grateful to Brother Hao. # 3. Drawing board I usually don’t have much time at work, so I took two days last weekend to briefly draw it. The main reference was my previous V3S schematic diagram and the open source schematic diagram of Brother Hao. [Brother Halo’s open source schematic diagram](chrome-extension://ibllepbpahcoppkjjllbabhnigcbffpi/https://whycan.com/files/members/3907/Schematic_V3x_2021-12-06.pdf) [My open source Quanzhi V3S](https:/ /www.oshwhub.com/lengyuefeng/v3scopy_copy) The power supply part uses EA3036, because Allwinner V3S also used this chip before, so it is relatively familiar. This time the main difference is the voltage. This chip only needs to modify the resistor, which can be calculated according to this formula. **Vout=0.6x(1+Ra/Rb)** When painting, I added a power amplifier and used 8002B. This is relatively cheap, only a few cents. The previous solution has been verified and it is more convenient to use. I saw that Brother Hao's schematic diagram used emmc. I originally wanted to add one, but after trying it, the BGA of the 4-layer board couldn't be fanned out at all, so I simply didn't want it. The RGB screen uses the punctual atomic interface. There is not much to say about this screen. The schematic diagram is quite messy and has not been sorted out, so just take a look at it. The PCB layout is also relatively random, and I don't pay attention to some situations, but it works anyway. I originally planned to put up four layers of boards, but later I found that it could be laid out even if it was squeezed, so I just settled for two layers. Post a 3D preview here! [image.png] # 4. Welding debugging ## 1. After the blank board was painted on the weekend, it was sent to be printed on Monday. The board is black. I think it looks better. No. Not to mention, the speed of Jialichuang is good. I successfully got the board when I got off work on Friday. It cost five yuan and the workmanship was very good. ![image.png] ## 2. Welding steps ### 1. Welding chip power supply Now I will introduce to you my general welding steps. After getting the blank board first, I will solder the power supply part first, and then measure whether the three voltages are normal. Now I like to blow directly with an air gun, which is faster. When applying solder paste and placing components, I drew them piece by piece when laying out, so it should be easier to distinguish. ![QQ picture 20220312201021.jpg] This is what it looks like after blowing. ![QQ picture 20220312201024.jpg] Everyone found that this switch was not soldered. It’s not that I didn’t want to solder it, but that I couldn’t find it in my inventory (really, I checked to see if there was anything missing before). There is no choice but to use tin to short-circuit these two pins. After checking that there is no short circuit, power on and test. **Three-way voltage:**![QQ picture 20220312200959.jpg] ![QQ picture 20220312201006.jpg] ![QQ picture 20220312201017.jpg] I don’t know whether it’s because the welder has improved or because of luck. Anyway, it was successful once and it went straight after powering on. The voltage output is normal. ### 2. After the peripheral power supply test of the welding chip is OK, we can weld the peripheral circuit of the chip. ![QQ picture 20220312201013.jpg] ![QQ picture 20220312201009.jpg] Solder the front and back. Then solder the main chip on. ![QQ picture 20220312201002.jpg] At this time, the SD card does not need to be soldered. You can solder the USB first, and then test whether the chip communicates. Everyone found that my USB is very ugly. This is because it is plugged in straight and the package I drew is SMD, so I had to bend it, but it is not unusable. ### 3. Power on USB test and open ubuntu. After plugging in the USB, the USB device will pop up in the window. If it does not pop up, please check the circuit. I identified it directly here. Then execute the sudo sunxi-fel -l command! [image.png] This status indicates that the chip has been correctly identified. At this time, there is generally no problem. You can directly load uboot and run the test in RAM. ### 4. Soldering other peripherals At this point, you can solder all the peripherals at once, and then slowly test them. You can also solder which ones you want, it’s up to you. ![QQ picture 20220312200936.jpg] ### 5. Makeover After we have soldered all the components, we can wipe the board with board washing water, so that it will look good. I have not washed it here because I bought it. The components haven't arrived yet (USB patch and switch), I'll wash them all at once after replacing them. Take your seat first and fill it in later. # 5. Software debugging ## 1.uboot First, you need to find a uboot to compile and run. After searching on Kengwang, I really found something. Kengwang is really a good thing. ![image.png] Compile according to this step and there will be no problem. After successful compilation, there will be a bin file in the current directory. ![image.png] Then execute this to run sudo sunxi-fel uboot u-boot-sunxi-with-spl.bin in RAM. Execute this to run sudo dd in SD if=u-boot-sunxi-with-spl.bin of=/dev /sdb bs=1024 seek=8 For details, please refer to [V3S uboot compilation](https://blog.csdn.net/lengyuefeng212/article/details/118861717). I forgot to take a screenshot of the startup log. There is Ethernet configuration later. ## 2. Why should uboot compile Ethernet to compile Ethernet? Because I have always used the method of mounting the file system to debug programs, and I find it more convenient to use. Reference link: [Compiling Ethernet](https://blog.csdn.net/lengyuefeng212/article/details/120000952) After configuring it in uboot, compiling, something went wrong! [image.png] But I’m still stuck. Found a solution online. Reference link: [Ethernet compilation problem](https://whycan.com/t_7269.html) ![image.png] After I configure it according to it, I can compile it. Whether the device tree configuration is correct, whether the compilation is completed, and whether the network is available, there is actually a place where you can look, which is the information printed by uboot at the beginning. When the following message appears, it means that our online registration is successful. ![image.png] After successful compilation, we need to test whether the network is available. First set the IP address, making sure it is on the same network segment as your ubuntu. setenv ipaddr 192.168.31.105 and then ping your computer. If it looks like this, it means the network is normal. ![image.png] ## 3. Set the mounted file system. There is only one uboot startup file in our SD card, which does not have a kernel and file system. I downloaded it through the Internet. I won’t talk about setting up the tftp service and nfs environment here. I only set environment variables here. It should be noted that the waiting time before starting the kernel of uboot compiled by default is 0. It needs to be modified here to facilitate testing. setenv bootdelay 5 setenv ipaddr 192.168.31.50 setenv serverip 192.168.31.103 setenv bootcmd 'setenv bootm_boot_mode sec;setenv ipaddr 192.168.31.50;setenv serverip 192.168.31.103;tftp 41000000 zI mage;tftp 41800000 sun8i-v3s-lichepi-zero-dock.dtb; bootz 0x41000000 - 0x41800000' setenv bootargs root=/dev/nfs rw nfsroot=192.168.31.103:/home/luatao/luatao/nfs/rootfs ip=192.168.31.50:192.168.31.103:192.168.31.1 :255.255.255.0::eth0 :off init=/linuxrc console=ttyS0,115200 The above should be configured according to your actual situation. Finally, execute saveenv to save the variables. There was a problem while saving. Unknown command 'saveenv' - try 'help' means this command does not exist. The solution is to enter the uboot configuration file! [image.png], remove 1, and check 2. You must remove 1 here, otherwise the error Saving Environment to nowhere... not possible! [image.png] will be reported, and then compile, and then Just re-burn uboot and start it. ![image.png] ## 4. Start the kernel log ![image.png] . . . ![image.png] Then you can have fun playing. # 6. Peripheral debugging # 7. Unsolved problems first appeared. During today's test, after mounting the file system, there was only sound on the screen and no driver when playing the video. The Linux kernel and rootfs use v3s. Check that there is no /dev/fb0 in the device. There was no problem using v3s before. Could it be the impression caused by uboot? It has not been solved yet, I will continue to look for the cause tomorrow. The picture displayed on the screen above is the burned image of Xiaozhi. If it can be displayed, it means that there is no problem with my screen hardware. [Xiaozhi link](https://whycan.com/t_7248.html) # 8. Application QT program. Fill in the # later. 9. To be continued Other additional functions, such as 3D shell, etc.