Lua scripts for norns and crow for Flash Crash performance on 2022/01/01 https://vimeo.com/662344765

flashcrash_20220101.lua

-- crow script loaded from norns, must be in crow/ subfolder
public{camera_preset = 0}
public{camera_animation = 0}
public{clock_phase = 0}

ii.self.call2 = function(f, v) 
  print("fc/crow: call2")
  if f == 1 then 
    public.camera_preset = v
  elseif f == 2 then
    public.clock_phase = v
  elseif f == 3 then
    public.camera_animation = v
  end
end

flashcrash_20220101_anagram.lua

-- flash crash 20220101
-- performance by anagram
-- author: @dewb

camera = {name="camera", port = nil, device = nil}
servo = {name="servo", port = nil, device = nil}

camera_metro = nil
camera_metro_refresh_fps = 5

speed_p = 0
speed_t = 0
speed_z = 0
max_speed = 24
camera_moving = false

function camera_metro_callback()
  local speed_p_norm = math.floor(speed_p + 0.5)
  local speed_t_norm = math.floor(speed_t + 0.5)
  local speed_z_norm = 0

  if (speed_p_norm ~= 0 or speed_t_norm ~= 0) then
    local dir_p = ((speed_p_norm == 0) and '\x03') or ((speed_p_norm > 0) and '\x01') or '\x02'
    local dir_t = ((speed_t_norm == 0) and '\x03') or ((speed_t_norm > 0) and '\x02') or '\x01'
    send_command('\x81\x01\x06\x01' .. string.char(math.abs(speed_p_norm)) .. string.char(math.abs(speed_t_norm)) .. dir_p .. dir_t .. '\xFF')
    camera_moving = true
  elseif camera_moving then
    camera_stop()
  end
end

function clamp_speed(speed)
  return math.max(-max_speed, math.min(max_speed, speed))
end



function send_command(str)
  if camera.port then
    camera.port:write(str)
    camera.port:flush()
    --while serial_port:read(1) ~= '\xFF' do
    --end
    --serial_port:read(3) -- ack response
    --serial_port:read(3) -- completion response
  end
end

function send_inquiry(str, response_length)
  send_command(str)
  return camera.port:read(response_length)
end

function camera_home()
  send_command('\x81\x01\x06\x04\xFF')
end

-- save current position to preset 1-6
function camera_save_preset(preset_num)
  if preset_num > 0 and preset_num < 9 then
    send_command('\x81\x01\x04\x3F\x01' .. string.char(preset_num - 1).. '\xFF')
  end
end

-- recall presets 1-6
function camera_recall_preset(preset_num)
  if preset_num > 0 and preset_num < 9 then
    send_command('\x81\x01\x04\x3F\x02' .. string.char(preset_num - 1) .. '\xFF')
  end
end
function camera_stop()
  speed_p = 0
  speed_t = 0
  speed_z = 0
  camera_moving = false
  send_command('\x81\x01\x06\x01\x15\x15\x03\x03\xFF')
end

function enc(n, delta)
  if n == 2 then
    --speed_p = clamp_speed(speed_p + delta * 0.4)
  elseif n == 3 then
    --speed_t = clamp_speed(speed_t + delta * 0.4)
  end
end

function key(n, z)
  if z == 1 and n == 2 then
    camera_recall_preset(2)
  end
end

function receive_serial_devices(thing, device_list, args)
  if thing.port then thing.port:close() end
    
  for d in device_list:gmatch("([^\n]*)\n?") do

    thing.port = io.open(d, "r+")
    if (thing.port) then
      thing.device = d
      print("Connected to " .. thing.name .. " at " .. thing.device)
      norns.system_cmd("stty -F " .. thing.device .. " 9600 cs8 -cstopb -parenb")
      break
    end
    
  end
end

function init()
  local camera_args = "9600 cs8 -cstopb -parenb"
  norns.system_cmd("bash -c 'ls /dev/ttyUSB*'", function(list) receive_serial_devices(camera, list, camera_args) end)
  local servo_args = "cs8 9600 ignbrk -brkint -icrnl -imaxbel -opost -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke noflsh -ixon -crtscts"
  norns.system_cmd("bash -c 'ls /dev/ttyACM1'", function(list) receive_serial_devices(servo, list, servo_args) end)

  camera_metro = metro.init(camera_metro_callback, 1/camera_metro_refresh_fps)
  camera_metro:start()
  
  start_crow()
end

function cleanup()
  if camera_metro then camera_metro:stop() end
  if serial_port then serial_port:close() end
end


function start_crow()
  function norns.crow.public.change(n, v) public_update(n, v) end
  function norns.crow.public.discovered()
    print'fc discovered crow public'
  end
  norns.crow.loadscript("flashcrash_20220101.lua")
end

function public_update(name, value)
  print("Crow public change detected")
  if name ~= nil then print(name) end
  if value ~= nil then print(value) end
  if name == "camera_preset" then
    camera_recall_preset(value)
  elseif name == "clock_phase" and value >= 1 and value <= 4 then
    local cmds = {"60", "80", "90", "105"}
    servo_command(cmds[value])
  elseif name == "camera_animation" and value >= 1 and value <= 4 then
    camera_animate(value)
  end
end

function servo_command(intstr)
  if servo.port ~= nil then
    servo.port:write(intstr .. "\n")
    servo.port:flush()
  end
end

function camera_animate(value)
  if value < 1 or value > 4 then
    return
  end
  
  local dir_p = '\x03'
  local dir_t = '\x03'
  local sp = 0
  local st = 0
  local s = 6
  if value == 1 then
    dir_t = '\x01'
    st = s
  elseif value == 2 then
    dir_p = '\x01' 
    sp = s
  elseif value == 3 then
    dir_t = '\x02'
    st = s
  elseif value == 4 then
    dir_p = '\x02'
    sp = s
  end
  
  clock.run(function()
    send_command('\x81\x01\x06\x01' .. string.char(sp) .. string.char(st) .. dir_p .. dir_t .. '\xFF')
    clock.sleep(0.2)
    send_command('\x81\x01\x06\x01' .. string.char(sp/2) .. string.char(st/2) .. dir_p .. dir_t .. '\xFF')
    clock.sleep(0.2)
    camera_stop()
    clock.sleep(0.2)
    camera_recall_preset(norns.crow.public.lookup("camera_preset").val)
    norns.crow.public.update("camera_animation", 0)
  end)
end