bad json payload

[costascontis]

i have found a weird bug(?) …using the original blakadder’s nspanel.be .When i change the thermostat’s setting for example from 19 to 20 i get at mqtt

{"NSPanel":{"ATCMode":0,"ATCExpect0":20}}

and everything is working ok parsing and transforming reading the number setpoint in openhab
but when i set to 21 and only then i get

{"NSPanel":{"ATCMode":0,"ATCExpect0":21}B}}

This is only happening with “21” value…

[mbbrenner]

I found the same... I found a little solution. Please comment....

def every_100ms()
   if self.ser.available() > 0
   var msg = self.ser.read()   # read bytes from serial as bytes
   import string
     if size(msg) > 0
       print("NSP: Received Raw =", msg)
       if msg[0..1] == self.header
         mode = "NSPanel"
         var lst = self.split_55(msg)
         for i:0..size(lst)-1
           msg = lst[i]
             if self.atc['mirror'] == true
               if msg[2] == 0x84 self.ser.write(msg)   # resend messages with type 0x84 for thermostat page
               end
             end
           var j = size(msg) - 1
           while msg[j] != 0x7D
             msg = msg[0..-1]
             j -= 1
           end        
           msg = msg[5..j]
             if size(msg) > 2
               if msg == bytes('7B226572726F72223A307D') # don't publish {"error":0}
               else 
               var jm = string.format("{\"NSPanel\":%s}",msg.asstring())
--->                if ((string.find(jm,"}B}")) != -1)
--->                    var substring =  string.split(jm, "}B}", 1) 
--->                    jm = substring[0]+substring[1]+"}"
--->                end
               
               tasmota.publish_result(jm, "RESULT")
               end
             end
         end
       elif msg == bytes('000000FFFFFF88FFFFFF')
         log("NSP: Screen Initialized")   # print the message as string
         self.screeninit()
       else
         var jm = string.format("{\"NSPanel\":{\"Nextion\":\"%s\"}}",str(msg[0..-4]))
         tasmota.publish_result(jm, "RESULT")        end       
     end
   end
 end

[yvesdm3000]

I have a similar issue with a bad json payload, but on scene buttons. I have 3 scene buttons, but when I press on the last button, the last '}' is doubled.
Press on the second button gives me:
{"id":"2"}
Press on the third button gives me:
{"id":"3"}}

[yvesdm3000]

See #27

[mulder82]

I had a similar issue and wrote my own version of the split_55 function, which checks the payload length in the data sent by the panel:

55 AA [type] [!!payload length!!] [00] [JSON payload] [crc] [crc].

In this version, no additional payload validation tests are needed and any value received from the display is processed correctly.

def split_55(b)
    var ret = []
    var maxpos = size(b)-1
    var pos = 0

    while pos <= maxpos - 7 # minimum message size 7 bytes
      if b[pos] == 0x55 && b[pos+1] == 0xAA #if valid message header
        pos+=3 #go to payload length
        var plength=b.get(pos,1) #get payload length
        pos+=2 #go to payload begining
        var payload = b[(pos..pos+plength-1)] #copy payload content
        ret.push(payload) #add to result
        pos+=plength+3 #go to next message => plength + 2 for crc +1 for x00 messages separator 
      else 
        return ret #if no valid message return
      end
    end

    return ret
  end