Learning Verilog with the CYC1000

Finally getting comfortable writing some basic verilog code to walk the LEDs on the CYC1000 FPGA board.

I started with using Quartus WIN10 VM (using VirtualBox) and moved to Linux with Quartus 18.1 Build 625.  Had to over come a couple of basic issues with Quartus on Linux:

1. Renamed /quartus/linux64/libstdc++.so to ./quartus/linux64/libstdc++.so.old for some reason, the library paths are not right when loading, will look at the more in the future.
2. Some of megafunctions lock up, so, resize the dialog before moving to the next option or entering any values.

 I have not tried in simulation, but compiling, loading to SPI Flash or to the FPGA works fine.

The first example was a simple walking LED and has a loopback for the RS232 for the FTDI chip.

The CYC1000 is connected to the Channel A and B of the FTDI FT2232H.  Channel A, is for JTAG and Channel B is RS232/HighSpeed Serial/Or SPI.

To get /dev/ttyUSB0 working, need to change the 51-arrow-programmer.rules to remove deleting the serial interface.

# Interface number zero is a JTAG.
# SUBSYSTEM=="usb",\
# ATTRS{idVendor}=="0403",\
# ATTRS{idProduct}=="6010",\
# ATTR{interface}=="Arrow USB Blaster",\
# ATTR{bInterfaceNumber}=="00"
# RUN="/bin/sh -c 'echo $kernel > /sys/bus/usb/drivers/ftdi_sio/unbind'"

The end project is to use the protocol over the serial interface over USB to control:

• SPI Master
• Controlling a LED strip
• 6 channel PWM decoder
• 4 channels of OneShot 150/42
• 4 channels DSHOT
•  I2C A/D converter 

The RS232 loopback is working at 3Mbps using minicom.  The next project will be getting a Serial RX/TX/FIFO working.

New FPGA boards

I'm constantly looking for new SBC and FPGA boards.  Here are a couple links:

• Alchitry: Digital Design Simplified Xilinx Artix 7 XC7A35T-1C  and iCE40 
• Cora Z7-10 Z7-07S Zynq boards 
• MKR Vidor 4000 board
• CYC1000 with Cyclone 10 FPGA, 8 MByte SDRAM
• MAX1000
• If local to US Arrow also stocks this board. 
• SBC
• Renegade Elite
• RK3399 Rock chip processor.  Quad-core A53 and Dual-core A72.

Xilinx and MiniZed board

Finally have a simple demo running on the PL (programmable logic) blinking the Red and Green LED.

Getting up to speed using Zync-7000 and Vivado (GUI) tool takes some time to get up to speed on.  Several weeks ago I took the the SpeedWay class, that was a great way to get an overall overview and help get a start on the MiniZed board.

Here is the led.c verilog (yes simple)

module led
#(
    parameter WIDTH = 24
   )
   (
    input wire Clk,
    input wire Reset,
    output  LED_G,
    output LED_R
    );
   
 integer counter = 0;
 reg LED_G_reg=0;
 reg LED_R_reg=0;
 
 assign LED_G = LED_G_reg;
 assign LED_R = LED_R_reg;

 always @(posedge Clk) begin
    /* if (Reset ==1 ) begin
        counter <= 0;
        LED_R_reg <=0;
        LED_G_reg <=0;
     end
     else */begin
 
            counter <= counter+1;
            LED_R_reg <= counter[23];
            LED_G_reg <= ~counter[23];
        end             
  end

endmodule


Some tips

• Linux with Wayland causes Vivado crash.  To work around this use X, hope they will fix it.
• Using a constraint file you must declare the output on the net list.  If not the block will not be generated.
• The Zynq PS clocks are used to drive the PL, so, must have a simple ARM program or init script to start the clocks.
• The MiniZed board is nice to use, low cost and has a lot of features to start learning FPGA or ARM (Linux or RTOS(FreeRTOS))

I can do a simple hello tutorial if requested.

Next steps:

1. Create a SWO trace/Serial Wire Viewer (SWV) demo on STM32 use using debug messages. Validate it is working using a logic anaylzer 
2. Create FPGA code to decode the Manchester bit stream and send it via DMA to the ARM-9 Cortex on the 

FreeRTOS trace HW/SW with nw.js application

While working on CleanFlight Linux with a I/O micro-controller for extra peripherals, there is no straight forward way to get performance, trace, and general information about the state of the firmware on the micro-controller.


Goal:

• Provide an open source solution to get metrics on the firmware using traceSWO port.

Implementation:

• Use FreeRTOS trace messages and send them out one of the channels of SWO port
• Also allow setting ETM tracing
• Create a GUI (nw.js) and command line tools to parse and show trace data from FreeRTOS
• GUI will show live line/bar charts of Task performance and I/O
• python tools to parse/mine data allows custom reports.

I have several GD32F103C8 red boards, use these to decode the SWO and send trace information to nw.js application.

Thoughts? suggestions? 

Cleanflight port to Linux (LinuxFlight) status

Created a new CLI (command Line Interface) module based on C++ and uses msgProtocol for subscribing/publishing messages.  This allows components (bash shell) or transports (UDP/TCP (Configurator)) to use the CLI at the same time.  So, now one instance of CLI can process messages from anywhere. For example: Linux has bash shell so, it would be nice not to startup Configurator to get basic info.  Use the bash shell

Here it is:
LinuxFlight>help
status - show status
help
tasks - show task stats
version - show v
LinuxFlight>status

System Uptime: 274 secondsVoltage: 0 * 0.1V (0S battery - NOT PRESENT)CPU Clock=500MHz, GYRO=MPU9250, ACC=MPU9250, MAG=AK8963
Stack size: 790724, Stack address: 0xc10b0CPU:0%, cycle time: 23226, GYRO rate: 43, RX rate: 282, System rate: 10Arming disable flags: TH
LinuxFlight>tasks

LinuxFlight>tasksTask list             rate/hz  max/us  avg/us maxload avgload     total/ms
00 - (         SYSTEM)     10       3       1    0.5%    0.5%         0
01 - (            PID)    444   22177     523  985.1%   23.7%      1270
   - (           GYRO)    889
02 - (          ACCEL)    997   21337     723 2127.7%   72.5%      1822
03 - (       ATTITUDE)     99     327      14    3.7%    0.6%         5
04 - (             RX)    143     166      36    2.8%    1.0%         9
05 - (         SERIAL)    101      87       4    1.3%    0.5%         1
08 - (BATTERY_CURRENT)    149      41       2    1.1%    0.5%         0
09 - ( BATTERY_ALERTS)      4       7       2    0.5%    0.5%         0
10 - (            GPS)     99     129       6    1.7%    0.5%         2
11 - (        COMPASS)     39   22825     756   89.5%    3.4%       158
14 - (      TELEMETRY)    255      39       2    1.4%    0.5%         0
15 - (       LEDSTRIP)    101    2522      74   25.9%    1.2%        30
RX Check Function                   0       0                         0
Total (excluding SERIAL)                      3239.9%
LinuxFlight>


Next is to get the battery voltage reporting and figure out the issue with the loading.

Might have to try the RT kernel but, first load LinuxFlight on to its own processor.  Also, might have to remove CPUFREQ it is known to impact realtime performance.

CleanFlight on Linux using micro-controller for PWM/LCD

Finally have micro-controller sending PWM from a HK-T6A to Linux version of CleanFlight. 

Created a new protocol (protocolMsg), allowing to route messages between software components over UDP or within the app via message bus.

For example, CleanFlight has a PWM parallel RX IO software block and PWM RX driver block.  The PWM RX driver block was replaced with a PWM client protocolMsg handler, the micro-controller is a PWM server protocolMsg handler.  The messages are routed via UDP over USB.  

The goal is to update CleanFlight  CLI and msp to handle message processing from multiple transports, i.e. serial, UDP, TCP. 


CleanFlight Configurator is proper showing receiver status. USB/UDP is running at 28Kb/s for RPM messages.

To Do list:

• validate new Linux serial driver
• a simple libevent shim (same as UDP/TCP shim)
• used for GPS
•  validate new lcdStrip Shim
• allows routing LCD strip messages (LED RGB) to be routed to micro-controller.
• write dshot  shim
• allow sending sdhot motor messages to micro-controller

OrangePI Zero overlay and uboot/armbian

The Armbian has good documentation about how to use device overlays for their uboot scripts.  I wanted to dive a little deeper and understand some of the basics and still use buildroot.

Boot process of uboot, there is a file on the FAT partition boot.src, this is a binary file generated by mkimage.  The source file is in board/orangepi/orangepi-zero boot.sh:
setenv fdt_high ffffffff
setenv load_addr "0x44000000"
echo "Boot script loaded from ${devtype}"

setenv bootargs console=ttyS0,115200 earlyprintk root=/dev/mmcblk0p2 rootwait

fatload mmc 0 $kernel_addr_r zImage
fatload mmc 0 $fdt_addr_r sun8i-h2-plus-orangepi-zero.dtb
fdt addr ${fdt_addr_r}
fdt resize 65536
setenv processorName sun8i-h3-
setenv overlays i2c0  spi-spidev
for overlay_file in ${overlays}; do
    echo " looking for  ${processorName}${overlay_file}.dtbo"
    if fatload mmc 0 ${load_addr} ${processorName}${overlay_file}.dtbo; then
        echo "Applying user provided DT overlay ${overlay_file}.dtbo"
        fdt apply ${load_addr} || setenv overlay_error "true"
    fi
done


bootz $kernel_addr_r - $fdt_addr_r

So, what happens is the device tree overlays are merged in uboot with the dtb file loaded for the board using fdt command line tools.  This allows to change the board dtb without always recompiling it.

Post any questions you have.   So, spi and i2c are now using device tree overlays.

Here is the overlay for SPI:
/dts-v1/;
/plugin/;

/ {
    compatible = "allwinner,sun8i-h3";

    fragment@0 {
        target-path = "/aliases";
        __overlay__ {
            spi0 = "/soc/spi@01c68000";
            spi1 = "/soc/spi@01c69000";
        };
    };

    fragment@1 {
        target = <&spi0>;
        __overlay__ {

            #address-cells = <1>;
            #size-cells = <0>;
            status = "disabled";

            spidev@1 {
                compatible = "linux,spidev";
                reg = <0>;
                spi-max-frequency = <1000000>;
            };
        };
    };

    fragment@2 {
        target = <&spi1>;
        __overlay__ {

            #address-cells = <1>;
            #size-cells = <0>;
            status = "okay";

            spidev@2 {
                compatible = "linux,spidev";
                reg = <0>;
                spi-max-frequency = <25000000>;
            };
        };
    };
};


so, this completes the task of using overlays.  Next DHCP and zeroconfig.

Also, have a modification to EEM USB handler, to improve performance.  Also, thinking of adding a way to use several packets at once based on the size of the packet.