pico_sign_sipf_xmodem

README (日本語)

fig.1: horizontal scrolled image output on 480x1920 display at 20Hz where image can be updated via LTE

(picture on loading derived from http://panoroman.nao3.net/72/img_0485/)

what is this ?

• show horizontal scrolled signboard on LCD display, powered by Raspberry Pi Pico and PicoDVI (https://github.com/Wren6991/PicoDVI)
• PicoDVI feat/x8scale modified branch (https://github.com/homelith/PicoDVI/tree/feat/x8scale) enables expanding image 8 times large, saving memory capacity to 60x1280 image that fits limited memory capacity on Raspberry Pi Pico
• signboard image will be updated via LTE, powered by SAKURA internet Mono Platform (https://iot.sakura.ad.jp/platform/) and its client device SCM-LTEM1NRF

building hardware (breadboard-based)

• note

  • DVI output tend to be unstable since breadboard has much poor signal transmission characteristics. Pray for success.
  • HDMI-ish connector pin assignments are compatible with Pico DVI Sock (https://github.com/wren6991/pico-dvi-sock)

• components

  • Raspberry Pi Pico

  • SCM-LTEM1NRF SAKURA internet Mono Platform evaluation module

    • currently anyone belongs to corporate entity can request one via https://iot.sakura.ad.jp/request_platform_devkit/ (they do not ship besides japan)
    • or you can purchase any number of units via third-party store (https://na-s.stores.jp/items/639927bd940f3d50b7c5a011)
    • assume generic sipf-std-client_nrf9160 firmware to be installed (https://github.com/sakura-internet/sipf-std-client_nrf9160)
    • tested with firmware on release v0.4.1 (https://github.com/sakura-internet/sipf-std-client_nrf9160/releases/tag/v0.4.1)

  • Hannstar HSD088IPW1 + HDMI-HSD088-V05 480x1280 vertical elongated display

    • currently available on shigezone (https://www.shigezone.com/product/slimlcd/)
    • placing jumper on HDMI-ish connector 5V supply pin on HDMI-HSD088-V05 helps supplying power via HDMI cable
    • warning : this is out of HDMI standard (+5V line current is limited up to 50mA), use thicker and shorter cable or the cable may catch fire. TRY AT YOUR OWN RISK
    • generic 640x480 display can be alternative. To use them, modify PicoDVI parameters on sw/app/main.c

  • HD03VLP20D HDMI signal breakout board

    • currently available on aitendo (https://www.aitendo.com/product/19221)
    • you can use Pico-DVI-Sock based extension (https://www.switch-science.com/products/7431) as an alternative and may get much higher signal integrity

  • 5V DC power sources with 2 amps or more

  • some dumper resisters (e.g. from 10 to 100 ohms) for DVI signals

  • some tactile switches

  • some jump wires

• see docs/breadboard-sch.pdf for wiring

fig.2: experimental setup on breadboard

build software

• prepare environment

  • some linux based distros (tested under native ubuntu 20.04 LTS and WSL2 ubuntu 20.04 LTS)
  • sudo apt install git gcc make cmake gcc-arm-none-eabi libnewlib-arm-none-eabi build-essential golang

• compile uf2 binary

  • you'll get sw/build/app/pico_sign_board.uf2 after compilation

$ git clone --recursive git@github.com:homelith/pico_sign_sipf_xmodem.git
$ cd pico_sign_sipf_xmodem/sw
$ make

• convert source image
  • prepare width 60px x height 1280px image as ${FILENAME}.png
  • confirm generated binary has exactly 153600 bytes of size

$ cd pico_sign_sipf_xmodem/sw/tools/png2array
$ make
$ ./png2array -m rgb565 -f bin ${FILENAME}.png > ${FILENAME}.bin

run on device

• download uf2 on Raspberry Pi Pico

  • power on Pico with BOOTSEL button pressed to make Pico run on USB mass storage device mode
  • place pico_sign_board.uf2 file on Pico-emulated USB storage root directory
  • you will see "Pico Bitbang DVI" sample images scrolled horizontally

• update signboard image

  • assume SCM-LTEM1NRF module associated with a Mono Platform project and websocket service adapter on your SAKURA Cloud account.
  • From project tab, upload ${FILENAME}.bin to associated project (fig.3)
  • From service adapter tab, issue "send message to device" command (fig.4)
    • parameters : tags;{any 8bit hex value}, type;variable length string, value;${FILENAME}.bin
  • Pico polls any new messages on every 3 minites by default or you can trigger it immediately by pressing tactile switch to drive Pico GP6 pin to GND.
  • Once Pico found new messages with ${FILENAME}.bin, xmodem downloader will be initiated and the image will be updated consequently.

• update signboard scroll speed

  • default scroll speed 16 pixel/frame can be update via Mono Platform message struct
  • assume SCM-LTEM1NRF module associated with a Mono Platform project and websocket service adapter on your SAKURA Cloud account.
  • From service adapter tab, issue "send message to device" command.
    • parameters : tags;{any 8bit hex value}, type; int16 value, value; from -32768 to 32767
  • Pico polls any new messages on every 3 minites by default or you can trigger it immediately by pressing tactile switch to drive Pico GP6 pin to GND.
  • Once Pico found new messages with int16 value, scroll speed will be updated to {int16 value} pixel / frame.

fig.3: upload sign_board.bin on SAKURA Mono Platform project tab

fig.4: sending message on SAKURA Mono Platform service adapter tab, notifying device filename to be downloaded