AP_Scripting: add SN-GCJA5 particle sensor example

libraries/AP_Scripting/examples/SN-GCJA5-particle-sensor.lua

@@ -0,0 +1,193 @@
+--[[
+    This script reads a SN-GCJA5 panasonic particle sensor on i2c
+    reading will be saved to data flash logs, CSV file and streamed as named value floats
+
+    Development of this script was sponsored by Cubepilot
+
+    the code is heavily based on the SparkFun arduino library
+    https://github.com/sparkfun/SparkFun_Particle_Sensor_SN-GCJA5_Arduino_Library
+]]--
+
+-- search for a index without a file, this stops us overwriting from a previous run
+local index = 0
+local file_name
+while true do
+  file_name = string.format('Particle %i.csv',index)
+  local file = io.open(file_name)
+  local first_line = file:read(1) -- try and read the first character
+  io.close(file)
+  if first_line == nil then
+    break
+  end
+  index = index + 1
+end
+
+-- open file and make header
+file = assert(io.open(file_name, 'w'), 'Could not make file :' .. file_name)
+file:write('Lattitude (°), Longitude (°), Absolute Altitude (m), PM 1.0, PM 2.5, PM 10, count 0.5, count 1, count 2.5, count 5, count 7.5, count 10\n')
+file:close()
+
+-- load the i2c driver, bus 0
+local sensor = i2c.get_device(0,0x33)
+sensor:set_retries(10)
+
+-- register names
+local SNGCJA5_PM1_0 = 0x00
+local SNGCJA5_PM2_5 = 0x04
+local SNGCJA5_PM10 = 0x08
+local SNGCJA5_PCOUNT_0_5 = 0x0C
+local SNGCJA5_PCOUNT_1_0 = 0x0E
+local SNGCJA5_PCOUNT_2_5 = 0x10
+local SNGCJA5_PCOUNT_5_0 = 0x14
+local SNGCJA5_PCOUNT_7_5 = 0x16
+local SNGCJA5_PCOUNT_10 = 0x18
+local SNGCJA5_STATE = 0x26
+
+-- Reads two consecutive bytes from a given location
+local function readRegister16(addr)
+  local lsb = sensor:read_registers(addr+0)
+  local msb = sensor:read_registers(addr+1)
+  if lsb and msb then
+    return msb << 8 | lsb
+  end
+end
+
+-- Reads four consecutive bytes from a given location
+local function readRegister32(addr)
+  local ll = sensor:read_registers(addr+0)
+  local lh = sensor:read_registers(addr+1)
+  local hl = sensor:read_registers(addr+2)
+  local hh = sensor:read_registers(addr+3)
+  if ll and lh and hl and hh then
+    return (hh << 24) | (hl << 16) | (lh << 8) | (ll << 0)
+  end
+end
+
+local function getPM(pmRegister)
+  local count = readRegister32(pmRegister)
+  if count then
+    return count / 1000.0
+  end
+end
+
+function update() -- this is the loop which periodically runs
+
+  -- read status
+  local state = sensor:read_registers(SNGCJA5_STATE)
+  if not state then
+    gcs:send_text(0, "Failed to read particle sensor state")
+    return update, 10000
+  end
+
+  local Sensors = (state >> 6) & 3
+  local PD =  (state >> 4) & 3
+  local LD =  (state >> 2) & 3
+  local Fan = (state >> 0) & 3
+
+  -- report sensor errors
+  if Sensors ~= 0 then
+    if Sensors == 1 then
+      gcs:send_text(0, "particle sensor: One sensor or fan abnormal")
+    elseif Sensors == 2 then
+      gcs:send_text(0, "particle sensor: Two sensors or fan abnormal")
+    else
+      gcs:send_text(0, "particle sensor: Both sensors and fan abnormal")
+    end
+    return update, 10000
+  end
+
+  -- report photo diode errors
+  if PD ~= 0 then
+    if statusPD == 1 then
+      gcs:send_text(0, "particle sensor: Photo diode: Normal w/ software correction")
+    elseif statusPD == 2 then
+      gcs:send_text(0, "particle sensor: Photo diode: Abnormal, loss of function")
+    else
+      gcs:send_text(0, "particle sensor: Photo diode: Abnormal, with software correction")
+    end
+    return update, 10000
+  end
+
+  -- report laser diode errors
+  if LD ~= 0 then
+    if LD == 1 then
+      gcs:send_text(0, "particle sensor: Laser diode: Normal w/ software correction")
+    elseif LD == 2 then
+      gcs:send_text(0, "particle sensor: Laser diode: Abnormal, loss of function")
+    else
+      gcs:send_text(0, "particle sensor: Laser diode: Abnormal, with software correction")
+    end
+    return update, 10000
+  end
+
+  -- report fan errors
+  if Fan ~= 0 then
+    if Fan == 1 then
+      gcs:send_text(0, "particle sensor: Fan: Normal w/ software correction")
+    elseif Fan == 2 then
+      gcs:send_text(0, "particle sensor: Fan: In calibration")
+    else
+      gcs:send_text(0, "particle sensor: Fan: Abnormal, out of control")
+    end
+    return update, 10000
+  end
+
+  -- read mass density
+  local PM1_0 = getPM(SNGCJA5_PM1_0)
+  local PM2_5 = getPM(SNGCJA5_PM2_5)
+  local PM10  = getPM(SNGCJA5_PM10)
+
+  if (not PM1_0) or (not PM2_5) or (not PM10) then
+    gcs:send_text(0, "Failed to read particle sensor mass density")
+    return update, 10000
+  end
+
+  -- read particle counts
+  local PC0_5 = readRegister16(SNGCJA5_PCOUNT_0_5)
+  local PC1_0 = readRegister16(SNGCJA5_PCOUNT_1_0)
+  local PC2_5 = readRegister16(SNGCJA5_PCOUNT_2_5)
+  local PC5_0 = readRegister16(SNGCJA5_PCOUNT_5_0)
+  local PC7_5 = readRegister16(SNGCJA5_PCOUNT_7_5)
+  local PC10  = readRegister16(SNGCJA5_PCOUNT_10)
+
+  if (not PC0_5) or (not PC1_0) or (not PC2_5) or (not PC5_0) or (not PC7_5) or (not PC10) then
+    gcs:send_text(0, "Failed to read particle sensor counts")
+    return update, 10000
+  end
+
+  local lat = 0
+  local lng = 0
+  local alt = 0
+
+  -- try and get true position, but don't fail for no GPS lock
+  local position = ahrs:get_position()
+  if position then
+    lat = position:lat()*10^-7
+    lng = position:lng()*10^-7
+    alt = position:alt()*0.01
+  end
+
+  -- write to csv
+  file = io.open(file_name, 'a')
+  file:write(string.format('%0.8f, %0.8f, %0.2f, %0.4f, %0.4f, %0.4f, %i, %i, %i, %i, %i, %i\n',lat,lng,alt,PM1_0,PM2_5,PM10,PC0_5,PC1_0,PC2_5,PC5_0,PC7_5,PC10))
+  file:close()
+
+  -- save to data flash
+  logger.write('PART','PM1,PM2.5,PM10,Cnt0.5,Cnt1,Cnt2.5,Cnt5,Cnt7.5,Cnt10','fffffffff',PM1_0,PM2_5,PM10,PC0_5,PC1_0,PC2_5,PC5_0,PC7_5,PC10)
+
+  -- send to GCS
+  gcs:send_named_float('PM 1.0',PM1_0)
+  gcs:send_named_float('PM 2.5',PM2_5)
+  gcs:send_named_float('PM 10',PM10)
+
+  gcs:send_named_float('count 0.5',PC0_5)
+  gcs:send_named_float('count 1,',PC1_0)
+  gcs:send_named_float('count 2.5,',PC2_5)
+  gcs:send_named_float('count 5,',PC5_0)
+  gcs:send_named_float('count 7.5,',PC7_5)
+  gcs:send_named_float('count 10,',PC10)
+
+  return update, 1000 -- reschedules the loop, 1hz
+end
+
+return update() -- run immediately before starting to reschedule