Merge pull request tinyelixir#1 from tinyelixir/tft-changes

Change from inky to tft

README.md

@@ -4,10 +4,12 @@ A library to provide a Scenic framework driver implementation for SPI serial con
 
 This driver only runs on RPi devices as far as we know as it is based on the scenic rpi driver generating a framebuffer we can use.
 
+Many thanks to the work on the Inky Scenic Driver folks (https://github.com/pappersverk/scenic_driver_inky) who worked through the framebuffer capturing from rpi, and Frank Hunleth for his tireless work (https://github.com/fhunleth/rpi_fb_capture) (as always)
+
 ## Installation
 
 The package can be installed
-by adding `scenic_driver_inky` to your list of dependencies in `mix.exs`:
+by adding `scenic_driver_fb_tft` to your list of dependencies in `mix.exs`:
 
 ```elixir
 def deps do

lib/scenic_driver_fb_tft.ex

@@ -0,0 +1,59 @@
+defmodule ScenicDriverFBTFT do
+  use Scenic.ViewPort.Driver
+
+  alias Scenic.ViewPort.Driver
+  require Logger
+
+  @default_refresh_rate 200
+  @minimal_refresh_rate 100
+
+  @impl true
+  def init(viewport, size, config) do
+    vp_supervisor = vp_supervisor(viewport)
+    {:ok, _} = Driver.start_link({vp_supervisor, size, %{module: Scenic.Driver.Nerves.Rpi}})
+
+    interval =
+      cond do
+        is_integer(config[:interval]) and config[:interval] > 100 -> config[:interval]
+        is_integer(config[:interval]) -> @minimal_refresh_rate
+        true -> @default_refresh_rate
+      end
+
+    {width, height} = size
+    {:ok, cap} = RpiFbCapture.start_link(width: width, height: height, display: 0)
+
+    Process.send_after(self(), :capture, 4_000)
+
+    {:ok,
+     %{
+       viewport: viewport,
+       size: size,
+       cap: cap,
+       last_crc: -1,
+       interval: interval
+     }}
+  end
+
+  @impl true
+  def handle_info(:capture, state) do
+    {:ok, frame} = RpiFbCapture.capture(state.cap, :rgb565)
+
+    crc = :erlang.crc32(frame.data)
+
+    if crc != state.last_crc do
+      File.write("/dev/fb1", frame.data)
+    end
+
+    Process.send_after(self(), :capture, state.interval)
+    {:noreply, %{state | last_crc: crc}}
+  end
+
+  defp vp_supervisor(viewport) do
+    [supervisor_pid | _] =
+      viewport
+      |> Process.info()
+      |> get_in([:dictionary, :"$ancestors"])
+
+    supervisor_pid
+  end
+end

mix.exs

@@ -5,8 +5,8 @@ defmodule ScenicDriverInky.MixProject do
 
   def project do
     [
-      app: :scenic_driver_inky,
-      version: "1.0.0",
+      app: :scenic_driver_fb_tft,
+      version: "0.1.0",
       elixir: "~> 1.8",
       description: description(),
       package: package(),
@@ -28,22 +28,21 @@ defmodule ScenicDriverInky.MixProject do
       {:scenic, "~> 0.9"},
       {:scenic_driver_nerves_rpi, "~> 0.9", targets: @pi_targets},
       {:rpi_fb_capture, "~> 0.1", targets: @pi_targets},
-      {:inky, "~> 1.0.0"},
       {:ex_doc, ">= 0.0.0", only: :dev}
     ]
   end
 
   defp description do
-    "Pimoroni Inky driver for Scenic"
+    "Framebuffer TFT driver for Scenic"
   end
 
   defp package do
     %{
-      name: "scenic_driver_inky",
+      name: "scenic_driver_fb_tft",
       description:
-        "A library to provide a Scenic framework driver implementation for the Inky series of eInk displays from Pimoroni. Built on top of the pappersverk/inky library. All in Elixir.",
+        "A library to provide a Scenic framework driver implementation for generic TFT devices over SPI.",
       licenses: ["Apache-2.0"],
-      links: %{"GitHub" => "https://github.com/lawik/scenic_driver_inky"}
+      links: %{"GitHub" => "https://github.com/makerion/scenic_driver_fb_tft"}
     }
   end
 end