# Parsing Problem **URL:** \ **Category:** Connectivity\ **Tags:** photon\ **Created:** [January 21, 2020, 4:53pm UTC](https://community.particle.io/t/parsing-problem/54307 "2020-01-21T16:53:08Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![JTravers555](https://avatars.discourse-cdn.com/v4/letter/j/4af34b/32.png) [@JTravers555](https://community.particle.io/u/JTravers555)\ **Post date:** [January 21, 2020, 4:53pm UTC](https://community.particle.io/t/parsing-problem/54307/1 "2020-01-21T16:53:08Z")
Hello, My project involves having a Parallax Propeller control my well system for my house. That part I have sorted out and working well, and having learned a little about the Photon, I’ve got one connected to my Propeller, with the intent of having the Prop send a string to the Photon: \<255,324,155,200\> \0. The four ints are numbers from my well I’d like to port over to Adafruit IO and see on a dashboard trend. The Prop is a 3.3V device, and I have it sending a serial string to the Photon’s RX terminal, and a common ground between the two of course. It’s just a straight connection. Unfortunately, I’m having no luck getting the parsing accomplished, the below code is me trying to see if I can get the string parsed and into variables so I can see them on my iphone Particle App, or the console. Can anyone tell me what I’m doing wrong? Thanks! ```cpp // Example 5 - Receive with start- and end-markers combined with parsing const byte numChars = 32; char receivedChars[numChars]; char tempChars[numChars]; // temporary array for use when parsing // variables to hold the parsed data char messageFromPC[numChars] = {0}; int integerFromPC = 0; int Height, WellGallons, TankGallons, WaterUsed; boolean newData = false; //============ void setup() { Particle.variable("Height", &Height, INT); Particle.variable("WellGallons", &WellGallons, INT); Particle.variable("TankGallons", &TankGallons, INT); Particle.variable("WaterUsed", &WaterUsed, INT); Serial1.begin(9600, SERIAL_8N1); } //============ void loop() { recvWithStartEndMarkers(); if (newData == true) { strcpy(tempChars, receivedChars); // this temporary copy is necessary to protect the original data // because strtok() used in parseData() replaces the commas with \0 parseData(); newData = false; } } //============ void recvWithStartEndMarkers() { static boolean recvInProgress = false; static byte ndx = 0; char startMarker = '<'; char endMarker = '>'; char rc; while (Serial.available() > 0 && newData == false) { rc = Serial.read(); if (recvInProgress == true) { if (rc != endMarker) { receivedChars[ndx] = rc; ndx++; if (ndx >= numChars) { ndx = numChars - 1; } } else { receivedChars[ndx] = '\0'; // terminate the string recvInProgress = false; ndx = 0; newData = true; } } else if (rc == startMarker) { recvInProgress = true; } } } //============ void parseData() { // split the data into its parts char * strtokIndx; // this is used by strtok() as an index strtokIndx = strtok(NULL, ","); // this continues where the previous call left off Height = atoi(strtokIndx); // convert this part to an integer strtokIndx = strtok(NULL, ","); WellGallons = atoi(strtokIndx); // convert this part to an int strtokIndx = strtok(NULL, ","); TankGallons = atoi(strtokIndx); // convert this part to an int strtokIndx = strtok(NULL, ","); WaterUsed = atoi(strtokIndx); // convert this part to an int } ``` ---
**Author:** ![ScruffR](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/scruffr/32/6952_2.png) [@ScruffR](https://community.particle.io/u/ScruffR)\ **Post date:** [January 21, 2020, 6:21pm UTC](https://community.particle.io/t/parsing-problem/54307/2 "2020-01-21T18:21:33Z")
The first call to `strtok()` must have the source string as first parameter, only _ **after** _ that you can use `NULL` to _continue_ on the same string. But without actually knowing which string to work on it’s impossible to _continue_. You even state that fact in your comment `// this continues where the previous call left off`. No previous call left off anywhere AFAICT: BTW, you can use the `Stream` functions like [`readBytesUntil()`](https://docs.particle.io/reference/device-os/firmware/photon/#readbytesuntil-) to read your string with much less effort and [`sscanf()`](http://www.cplusplus.com/reference/cstdio/sscanf/) to parse the data more concisely. You are also using outdated syntax for `Particle.variable()` For quite some time now your variables would simply be registered like this ```cpp Particle.variable("Height", Height); Particle.variable("WellGallons", WellGallons); Particle.variable("TankGallons", TankGallons); Particle.variable("WaterUsed", WaterUsed); ``` ---
**Author:** ![JTravers555](https://avatars.discourse-cdn.com/v4/letter/j/4af34b/32.png) [@JTravers555](https://community.particle.io/u/JTravers555)\ **Post date:** [January 21, 2020, 10:54pm UTC](https://community.particle.io/t/parsing-problem/54307/3 "2020-01-21T22:54:20Z")
Hey thanks for your reply. I’ve ammended the Particle variable calls, and put in recievedChars in place of the NULL for the first Parsing call. I copied that code largely from an Arduino tutorial of course, and didn’t delete out the comment. I flashed it, but still no joy. Tomorrows a new day and I’ll try to figure out those better ways you mentioned. Thanks. ---
**Author:** ![JTravers555](https://avatars.discourse-cdn.com/v4/letter/j/4af34b/32.png) [@JTravers555](https://community.particle.io/u/JTravers555)\ **Post date:** [January 23, 2020, 11:29pm UTC](https://community.particle.io/t/parsing-problem/54307/4 "2020-01-23T23:29:08Z")
Got it! I had a couple ‘Serial’ calls in there, not ‘Serial1’, also I had to add in a couple Particle.process() calls to keep it from breathing green. It’s my first real project that made it to IoT stage, and it’s awesome! Thanks for your help!