Pine A64+ single-board computer

This comes in a few different models, A64 and A64+ they are all 64-bit with 4 cores but RAM and IO varies.

Early notes

I have pledged on the highest specced version of this, A64+ which is runs at 1.2 GHz with 2 GB RAM.

Some links while I am waiting:
Homepage
Forum
Wiki with some info

The wiki has links and pictures, including pin-outs of the various connectors: PI-2, Euler, Exp, and Wifi/BT

Looks like there are the following IOs: from the picture at the home page, and just starting at the top left corner and going around:

For the connector named PI-2-Bus, the naming and form-factor suggests that this is going to be a set of gpio lines very similar to the 40 pins IO on Raspberry Pi devices. In fact, the pinout is as close to this as appeared to be possible -- ground and power pins are all in the same locations, as are the i2c, SPI, and UART functions.

There are several features here that are very similar to what we know from the Raspberry Pi: The power input is the same kind of micro-USB-B; there is a SD-card for the OS from which the device boots. Then there are USB connectors for keyboard and mouse, HDMI for a screen; wired Ethernet, GPIO signals (very likely that these are 3.3V).

It will be interesting to see how good this device works.

If this works as well as the Raspberry Pi does it will be a good alternative for those occasions when more computing power really is required.

The processor is Cortex A53, which turns out is the same as the one the Raspberry Pi 3 has. However, the Pine64+ has twice the RAM and what appears to be a wider Ethernet bandwidth, as it isn't limited by the USB2 channel of the Raspberry Pi. Also, it seems to be that a real 64-bit linux is being made available for the Pine64+ now, so it will be interesting to see how well it performs for the streamng SDR system that I am looking at. Since there is some kind of sound input on-board this might not require any separate sound card either.

2016-03-17: awaiting the two boards to arrive. Downloaded a Linux image (Arch Linux, 20160304, based on user longsleep's work.) This was in a RAR format file, and I found the unrar utility for Debian Non-free, to be able to pull the .img file from within. Now this is ready to go onto an SD card, process the same as for the Raspberry Pi devices.

2016-04-19: Boards have arrived. Pulled down Debian Jessie from the link in the forums. (Great thanks to longsleep and lenny.raposo)

The System shows that sizeof(char *) = 8 and sizeof(size_t) = 8 so we have 64-bit architecture. sizeof(time_t) = 8 also, so there is no year-2038 problem to be expected here! No software support for i2c or spi apparently (yet). There is also limited modules available for serial-port and other usb-connected devices. As of now, the PL2303 in the Adafruit cable does not yet have the driver available. However the ftdi_sio has a driver, and plugging in an FT232RL-based device does work well -- we get the /dev/ttyUSB0 device for this. More on UART0 below.

There is an RTC onboard and the hwclock utility does work. NTP client is also up, so I get the correct time from various chimers right away.

Userland GPIO support also exists however, as we have the /sys/class/gpio directory.

GPIOs

J47 Pi-2 Connector

J48 Euler "e" Connector

The unit can be powered via the micro-usb connector, or with 5V applied to pins 2 and 4 on J48, 0V on any or all of the pins 6, 9, 14, 20, 25, 34.

J51 Exp Connector

The (E) means the gpio-line appears to support edge-triggered interrupts.

J49 Wifi+BT Port (14-pin) 2mm pitch

J50 Wifi+BT Port (16-pin) 2mm pitch

Serial ports

There are 6 serial ports defined, of which at least 5 can operate with terminals or in any other way that serial ports can be used. Three of the ports have the RTS/CTS handshaking line pair also. UART0 TX and RX appear on both J48 and J51. The serial ports defined are available at the following pins:

The signal levels on these are 3.3V so the connections to a standard DE9 plug shown will have to be made via level translators in an ST3232 or similar that converts from RS-232 Mark and Space to 3.3V-system H and L.

Note that UART1 (/dev/ttyS1) is used for the Bluetooth subsystem so it will not be directly available if the wireless card is being used.

There is a getty going on ttyS0 (UART0) and in order to start these on other serial ports, use something like what is shown here for ttyS2 here:

systemctl enable serial-getty@ttyS2.service
systemctl start serial-getty@ttyS2.service

Similarly, in order to remove the getty the equivalent commands are:

systemctl stop serial-getty@ttyS2.service
systemctl disable serial-getty@ttyS2.service

I2C

To enable i2c, use:

apt-get install i2c-tools libi2c-dev

i2cdetect -y 1 generates messages in the system log for all the unconnected addresses,

sunxi_i2c_do_xfer()902 - [i2c1] incomplete xfer (status: 0x20, dev addr 0x77)

and it produces a different message

twi_start()370 - [i2c1] START can't sendout!

when there is nothing connected to the TWI1 pins (J47-3 and J47-5).

i2cdetect -y 0 generates similar messages:

twi_start()370 - [i2c0] START can't sendout!

whether or not anything is connected to pins J47-27 and J47-28 or not.

The TWI1 / i2c-1 buss on J47-3 and J47-5 does not appear to have pull-up resistors, unlike the Raspberry Pi. I have also not got the TWI0 / i2c-0 buss on J47-27 and J47-28 to do anything yet.

There is the GUI, and I can now see things on a VGA screen connected via an HDMI-VGA adapter. This version of the OS has i2c enabled and available and plugging a card with an "ASE4" chip onto the Rpi2 connector (it has connections to the 6 first pins, that are power, ground, and i2c) showed this appeared at address 0x0f with i2cdetect -y 1.

Programs for communicating with devices here worked right away, using the i2c_smbus_ series of functions declared in #include<linux/i2c-dev.h>

GPIO-numbering

( found info here in the forum.pine64.org )

There are several banks of gpios, identified with letters, so A=0, B=1, C=2 etc. Multiply this letter-code by 32 and add the number following as per:

/* Convert the hardware spec strings such as PC7 into equivalent GPIOnnn names. 
	Returns the calculated gpio number. */ 

int convertgpioname(char *gname,    /* String with PC15 or similar string in it */
	char *gpiofile,                 /* Name of the GPIOnnn file */
	size_t gpiofilemax)             /* Available length of this */
{
	int gpiono;
	char gpiofile[40];

	gpiono = (gname[1] - 'A') * 32 + strtol(gname+2, NULL, 10); 
	snprintf(gpiofile, gpiofilemax, "gpio%u", gpiono);
	return(gpiono);
}

Thus, for example, Pi-2 connector pin 11, named PC7, has C=2, times 32 is 64, then add the 7, for a total of 71, so this is identified as GPIO71.

Write 71 to /sys/class/gpio/export. The system makes the /sys/class/gpio/gpio71/ directory for us with the usual contents.

We now have /sys/class/gpio/gpio71/direction to be set to "in" or "out" -- even if it starts out saying "in" it doesn't read inputs until written. Then "value" will contain 0 for L and 1 for H or vice versa according to the setting of "active_low"

We notice that there is no "edge" for gpio71 -- it doesn't support interrupts. Another higher-numbered one, PH9, or GPIO233, does support them, so we have to do some discovery on this.

The GPIOS that have this "edge" are the ones in the PB, PH and PL series: PB0 thru PB9, 32-41, PH2-226, PH3-227, PH5 thru PH9, 229-233, PL8 thru PL11, 360-363, PL2 thru PL6, 354-358 (not tested)

Also, pin Pi-2/26, PH7, was being used for something in earlier kernels -- trying to export GPIO231 (231 = 7 + 7*32) returns "device busy".

This pin is free on the more recent Debian Mate system (3.10.101), and it also has the "edge" file, as noted above and in the pinout-table.

UART0

This is how to connect the Adafruit USB-Serial cable to pins 29, 30, and 34 on the J48 Euler connector or pins 7, 8, 6/9 on the J51 expansion connector: (TX, RX seen from the point of view of the Pine A64)

But there is a getty running on the UART0 at 115200, so I can log-in there if desired. Since the HDMI doesn't work this might be useful. I'm pretty sure that the details around i2c busses and such will be worked out in time. Apparently this has only been available for a couple weeks, and that in itself is actually quite impressive.

Interesting info about temperatures and such can be found in places like: /sys/devices/virtual/thermal/thermal_zone0/temp or even /sys/devices/platform/axp81x_board/axp-regulator.41/regulator/regulator.2/microvolts. There is a shell-script in /usr/local/sbin for reading things, sudo /usr/local/sbin/pine64_health.sh. The sudo part is needed for the processor-info.

Installation notes:

sudo password is the same as for login (password). Once having been able to log-in as pine64user, or debian, next is to update and get things going.

This is also useful in order to upgrade the system to the latest and greatest later on.

sudo
apt-get install -f
pine64_update_uboot.sh
pine64_update_kernel.sh
resize_rootfs.sh
reboot

Then after reboot, get some various necessary items in (such as the vim editor!):

apt-get update
apt-get upgrade
apt-get install vim

One or more of general Documentation, manual pages, and kernel-dev is also nice to have

apt-get install manpages manpages-dev linux-manual-3.16
apt-get install glibc-doc glibc-doc-reference 

For sound, a bug-fix said to get rid of the pulseaudio and put regular alsa in there instead. But there is no pulseaudio to be removed, so I just tried the rest of the recipe:

apt-get install alsa-base alsa-tools alsa-tools-gui alsa-utils alsa-oss alsamixergui libalsaplayer0
apt-get install libasound2-dev

May set EDITOR=vi and use visudo to edit and add

pine64user ALL=(ALL) NOPASSWD: ALL

Info on compiling kernel

apt-get install bc curl gcc git libncurses5-dev make u-boot-tools
git clone --depth 1 --single-branch -b pine64-hacks-1.2 https://github.com/longsleep/linux-pine64

2016-06-13

Revisiting: Downloaded first the Debian LXDE system on an 8 GB card that was no go. Boot, but showed problems with reading the card, so not all cards work equally well. Card writes and reads oke on another machine, could be timing problems with that. I might try this on another card, replacing the use of the first card loaded with the older kernel, described above.

Debian Mate however, on another, 32GB, card, worked.

After running resize_rootfs.sh it uses about 3 GB of the total 30 GB available.

(*E): GPIO231 is also now found to be available, and this is edge-triggered.

It turns out, the MAC address is set in the distro and not in the hardware. Running more than one of the same on a network thus won't work unless the MAC address is changed. This is defined in the file /boot/uEnv.txt where there is a line something like

ethaddr=36:c9:e3:f1:b8:05

I edited this to have last octet 07 instead for the second unit -- now both will co-operate on the network. Similarly, the hostname can be changed by editing it in /etc/hosts and in /etc/hostname

In order to upgrade the system to the latest and greatest later on, similar commands as were used initially are done, after having put the following into /etc/apt/sources.list:

deb http://ftp.us.debian.org/debian jessie main contrib non-free
deb-src http://ftp.us.debian.org/debian jessie main contrib non-free
deb http://security.debian.org/ jessie/updates main contrib non-free
deb-src http://security.debian.org/ jessie/updates main contrib non-free
deb http://ftp.us.debian.org/debian jessie-updates main contrib non-free
deb-src http://ftp.us.debian.org/debian jessie-updates main contrib non-free
deb http://httpredir.debian.org/debian jessie-backports main contrib non-free

pine64_update_uboot.sh
pine64_update_kernel.sh
reboot
apt-get update
apt-get upgrade
apt-get dist-upgrade

2016-08-01

I got the OpenWebRx SDR system to work fine on one of the PineA64+ that I have here. I have now put out an order for 5 more of these, as they seem very promising, also with the latest improvements to the kernels that have appeared on the forum.

2016-08-22

Operating temperature: -20 to +70 C

Voltages and currents on IO-lines:

Vi max = 3.6V

Vio 
3.3V - PB PC PF PH  
2.5V - PD PE
1.8V - PG PL

Voh = Vio-0.2V to Vio
Vol = 0V to 0.2V

Input Threshholds
Vih 0.7*VIO to VIO+0.3 V 
Vil 0.3*VIO to -0.3 V 

Ioz = Iih = Iil = 10 microA max

Pull-up and pull-down resistances, 100 K

Io max = 40 mA (absolute max rating)

Ioh = and Iol = are not specified, there is the Io max of 40 mA, but what is the current drawn (to GND or Vio) before the output voltage moves out of the Voh or Vol spec?

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