I used the guides "Connect Raspberry Pi to ThingWorx" and "Setup a Raspberry Pi as an IoT Device".
After setting up the EMS and connecting to TW i wanted to collect data with the Raspi UART pins / or UDP(same problem) so i could use the data for my property values.
For this i used the lua package manager luarocks to install the modules 'periphery' and 'socket':
sudo apt-get update
sudo apt-get install luarocks --package manager for Lua modules
sudo luarocks install luasocket (Web-Socket for UDP/TCPIP)
sudo luarocks install lua-periphery (Raspi GPIO access)
The data transfer script i created works fine on its own but when i want to implement it in my PiTemplate i get an error.
At first the script of the PiThing:
The serial connection starts at --Sensor Values; UART and ends with serial:close
require "shapes.swupdate"
module ("templates.200903_Paeslack_SimKI_TT", thingworx.template.extend)
properties.cpu_temperature={baseType="NUMBER", pushType="ALWAYS", value=0}
properties.cpu_freq={baseType="NUMBER", pushType="ALWAYS", value=0}
properties.cpu_volt={baseType="NUMBER", pushType="ALWAYS", value=0}
properties.Data1={baseType="NUMBER", pushType="ALWAYS", value=0}
properties.Data2={baseType="NUMBER", pushType="ALWAYS", value=0}
serviceDefinitions.GetSystemProperties(
output { baseType="BOOLEAN", description="" },
description { "updates properties" }
)
services.GetSystemProperties = function(me, headers, query, data)
log.trace("[200903_Paeslack_SimKI_TT]","########### in GetSystemProperties#############")
queryHardware()
-- if properties are successfully updated, return HTTP 200 code with a true service return value
return 200, true
end
function queryHardware()
-- use the vcgencmd shell command to get raspberry pi system values and assign to variables
-- measure_temp returns value in Celsius
-- measure_clock arm returns value in Hertz
-- measure_volts returns balue in Volts
local tempCmd = io.popen("vcgencmd measure_temp")
local freqCmd = io.popen("vcgencmd measure_clock arm")
local voltCmd = io.popen("vcgencmd measure_volts core")
--Sensor Values; UART
local periphery = require('periphery')
local Serial = periphery.Serial
-- Open /dev/ttyUSB0 with baudrate 115200, and defaults of 8N1, no flow control
local serial = Serial("/dev/serial0", 115200)
while true do
local buf = serial:read(26, 500)
--print(string.format("read %d bytes: _%s_", #buf, buf))
local Speedgoat_Input_String = tostring(buf)
print(buf)
end
serial:close()
-- set property temperature
local s = tempCmd:read("*a")
s = string.match(s,"temp=(%d+\.%d+)");
log.debug("[200903_Paeslack_SimKI_TT]",string.format("temp %.1f",s))
properties.cpu_temperature.value = s
-- set property frequency
s = freqCmd:read("*a")
log.debug("[200903_Paeslack_SimKI_TT]",string.format("raw freq %s",s))
s = string.match(s,"frequency%(45%)=(%d+)");
s = s/1000000
log.debug("[200903_Paeslack_SimKI_TT]",string.format("scaled freq %d",s))
properties.cpu_freq.value = s
-- set property volts
s = voltCmd:read("*a")
log.debug("[200903_Paeslack_SimKI_TT]",string.format("raw volts %s", s))
s = string.match(s,"volt=(%d+\.%d+)");
log.debug("[200903_Paeslack_SimKI_TT]",string.format("scaled volts %.1f", s))
properties.cpu_volt.value = s
end
tasks.refreshProperties = function(me)
log.trace("[200903_Paeslack_SimKI_TT]","~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In tasks.refreshProperties~~~~~~~~~~~~~ ")
queryHardware()
end
I skipped the data preprocessing because it changes nothing on the problem.
The task is quite simple. I want to read 26 bytes with 500 ms break, like seen in the script.
As i said it works well when i execute it on its own but when i want to use the UART-connection script in the Template this Error appears and i don't get any values printed:
[ERROR] 2020-11-26 13:53:58,331 luaScriptProxy::execute: [1979708496] Error executing script PiThing, Error = Error: error loading module 'periphery' from file '/usr/local/lib/lua/5.1/periphery.so':
/usr/local/lib/lua/5.1/periphery.so: undefined symbol: lua_gettop
[ERROR] 2020-11-26 13:53:58,331 luaScriptProxy::app_unlock: [1979708496] Attempt to unlock app_mutex while not holding it.L= 0x2f59b8
I assume that the library and syntax was not updated correctly.
Is it a problem for the PiTemplate / luaScriptResource that i installed the lua packages globally and not locally?
Does anybody has experience with such problems?
I appreciate any help and if anybody knows how to patch the lua path for the packages it would be great.
THX
