# Help with DHT22 and values

**URL:** <https://discourse.nodered.org/t/help-with-dht22-and-values/28359>\
**Category:** General\
**Created:** [15 June 2020 12:42 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359 "2020-06-15T12:42:18Z")\
**Posts on this page:** 17\
**Page:** 1

<div class="post-metadata">

**Author:** ![colint](https://avatars.discourse-cdn.com/v4/letter/c/8dc957/32.png) [@colint](https://discourse.nodered.org/u/colint)\
**Post date:** [15 June 2020 12:42 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/1 "2020-06-15T12:42:18Z")

</div>

Hello All,

I have a problem.Duhhh 🙂

I want to read-out a DHT22, that works and i am getting the string with tempurature and humidity.  
I can filter the values in 2 seperate payloads.  
But..  
How can i adjust the decimals.

example:  
DHT22 -\> 27.30 celcius  
-\> 53.00 humidity

change it in:  
DHT22 -\> 27.3c  
-\> 53

Thanks for you help,  
Colin

 ![Schermafbeelding 2020-06-15 om 14.35.44](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/a/0/a036b8b16d57baecd068ed6064c1e2ebfdf18213.png)

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [15 June 2020 13:03 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/2 "2020-06-15T13:03:48Z")

</div>

If you want to do that in order to display it in the dashboard then the dashboard nodes have the ability to set the number of decimal places by configuring the Value Format field. This is explained in the Gauge node info tab, I don't know about the others. So to specify one decimal place use `{{value | number:1}}`

If that is not why you want to do it can you explain the reason. It is usually best to keep all the precision you have till you want to display it.

---

<div class="post-metadata">

**Author:** ![colint](https://avatars.discourse-cdn.com/v4/letter/c/8dc957/32.png) [@colint](https://discourse.nodered.org/u/colint)\
**Post date:** [15 June 2020 13:24 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/3 "2020-06-15T13:24:24Z")

</div>

It is diplayed in the clock.

my flow

```auto
[{"id":"6bc50f94.1dba4","type":"tab","label":"Flow 1","disabled":false,"info":""},{"id":"4c49dd26.cee034","type":"ui_template","z":"6bc50f94.1dba4","group":"72cdc2ca.9d9cec","name":"Time and Temp","order":1,"width":15,"height":5,"format":"<script>\n var daylist = [\"zondag\", \"maandag\", \"dinsdag\", \"woensdag\", \"donderdag\", \"vrijdag\", \"zaterdag\"];\n (function(scope){ \n scope.$watch('msg', function(msg) {\n if (typeof(msg.payload) != \"undefined\") $(\"#DSEGTemp\").text(msg.payload);\n if (typeof(msg.colour) != \"undefined\") \n { \n if (msg.colour==\"orange\"){ $(\".Clock-Wrapper\").css('background-color', '#fb7c00'); $(\".lcdClock\").css('color', '#222'); } \n if (msg.colour==\"green\") { $(\".Clock-Wrapper\").css('background-color', '#66ac66'); $(\".lcdClock\").css('color', '#222'); } \n if (msg.colour==\"blue\") { $(\".Clock-Wrapper\").css('background-color', '#8888ff'); $(\".lcdClock\").css('color', '#222'); }\n if (msg.colour==\"yellow\"){ $(\".Clock-Wrapper\").css('background-color', '#bbbb44'); $(\".lcdClock\").css('color', '#222'); } \n if (msg.colour==\"white\") { $(\".Clock-Wrapper\").css('background-color', '#aaaaaa'); $(\".lcdClock\").css('color', '#222'); } \n if (msg.colour==\"pink\") { $(\".Clock-Wrapper\").css('background-color', '#ff8888'); $(\".lcdClock\").css('color', '#222'); } \n if (msg.colour==\"red\") { $(\".Clock-Wrapper\").css('background-color', '#aa2222'); $(\".lcdClock\").css('color', '#ccaa22'); } \n }\n });\n })(scope);\n\n function genTimerStrings(tm, num){\n \n \tvar i;\n \tvar ret = tm.toString(10);\n \tvar left = ret.length;\n \n \tif( left < num){\n \t\tfor(i=0; i<( num - left ); i++ ){\n \t\t\tret = String(0) + ret;\n \t\t}\n \t}\n \treturn ret;\n }\n\n function updateTimer(){\n \tvar ret;\n \tvar date = new Date();\n \tvar tm_year, tm_mon, tm_date, tm_hour, tm_min, tm_sec, tm_msec,tm_day;\n \tvar colon;\n \ttm_year = date.getFullYear();\n \ttm_mon = date.getMonth()+1;\n \ttm_date = date.getDate();\n \ttm_day = date.getDay();\n \ttm_hour = date.getHours();\n \ttm_min = date.getMinutes();\n \ttm_sec = date.getSeconds();\n \ttm_msec = date.getMilliseconds();\n \n \ttm_mon = genTimerStrings(tm_mon, 2);\n \ttm_date = genTimerStrings(tm_date, 2);\n \ttm_hour = genTimerStrings(tm_hour, 2);\n \ttm_min = genTimerStrings(tm_min, 2);\n \ttm_sec = genTimerStrings(tm_sec, 2);\n \ttm_day = daylist[tm_day];\n \n \tif( tm_msec > 499 ){\n \t\tcolon = ' ';\n \t}else{\n \t\tcolon = ':';\n \t}\n \n \tdocument.getElementById(\"DSEGClock\").innerHTML = tm_hour + colon + tm_min + \"<span style=\\\"font-size:30px;\\\">\" + tm_sec + \"</span>\";\n \tdocument.getElementById(\"DSEGClock-Year\").innerHTML = \"<span class=\\\"D7MI\\\">\" + tm_year + \"-\" + tm_mon + \"-\" + tm_date + ' ' + \"</span><span class=\\\"D14MI\\\">\" + tm_day + \".\" + \"</span>\";\n \n \tsetTimeout(\"updateTimer()\", 500 - date.getMilliseconds()%500 );\n }\n\n updateTimer();\n</script>\n\n<style type=\"text/css\">\n.masonry-container {\n overflow: hidden;\n}\n.lcdClock {\n\tbackground-color:#fbfbfb;\n\tfont-size:100%;\n\tpadding-left:10px;\n\tpadding-right:10px;\n\tpadding-bottom:10px;\n\tmax-width:300px;\n\tline-height:160%;\n\tcolor:#00cc55;\n\tfont-family:Meiryo, 'Lucida Grande','Hiragino Kaku Gothic ProN', sans-serif;\n}\n\n@font-face {\n font-family: \"D7MI\";\n src: url(\"/myfonts/DSEG7Modern-Italic.woff\") format('woff');\n}\n\n@font-face {\n font-family: \"D14MI\";\n src: url(\"/myfonts/DSEG14Modern-Italic.woff\") format('woff');\n}\n\n@font-face {\n font-family: \"D7MBI\";\n src: url(\"/myfonts/DSEG7Modern-BoldItalic.woff\") format('woff');\n}\n\n@font-face {\n font-family: \"DWEATHER\";\n src: url(\"/myfonts/DSEGWeather.woff\") format('woff');\n}\n\n.D7MI {\nfont-family: \"D7MI\";\n}\n\n.D7MBI {\nfont-family: \"D7MBI\";\n}\n\n.D14MI {\nfont-family: \"D14MI\";\n}\n\n.DWEATHER {\nfont-family: \"DWEATHER\";\nfont-size:72px;\nheight:72px;\n}\n\n.Clock-Wrapper{\n\tposition:relative;\n\tborder:6px solid #000;\n\tborder-radius:9px;\n\theight:68px;\n\twidth:280px;\n\tbackground-color:#fb7c00;\n\tbackground-color:#000000;\n\n\tbox-shadow: 4px 4px 28px 0px rgba(0,0,0,0.3) inset;\n\t-moz-transform: scale(2.52); /* for Firefox, default 1*/\nzoom:252%; /* For Chrome, IE, default 100%*/\n}\n\n.Clock-Time-Background{\n\tz-index:50;\n\tcolor:rgba(0,0,0,0.15);\n}\n\n.Clock-Time-Front{\n\tz-index:100;\n}\n\n.Clock-Time-Background,.Clock-Time-Front {\n \tposition:absolute;\n\ttop:38px;\n\tleft:5px; \n\tfont-size:42px;\n}\n\n.Clock-Year-Background{\n\tz-index:50;\n;\n\tcolor:rgba(0,0,0,0.1);\n\tfont-size:18px;\n}\n\n.Clock-Year-Front{\n\tz-index:100;\n}\n\n.Clock-Year-Background,.Clock-Year-Front {\n \tposition:absolute;\n\ttop:2px;\n\tleft:5px; \n\tfont-size:18px;\n}\n\n.temp { z-index:100; }\n.tempBack { z-index:50; color:rgba(0,0,0,0.1); }\n.temp,.tempBack {\n \tposition:absolute;\n\ttop:28px;\n\tleft:210px; \n\tfont-size:18px;\n}\n\n.tempc { z-index:100; }\n.tempcBack { z-index:50; color:rgba(0,0,0,0.1); }\n.tempc,.tempcBack {\n \tposition:absolute;\n\ttop:36px;\n\tleft:278px; \n\tfont-size:24px;\n}\n\n#DSEG7_OUTPUT{\n\tfont-family: \"D7MI\";\n}\n\n#DSEG14_OUTPUT{\n\tfont-family: \"D14MI\";\n}\n\n#DSEG14_OUTPUT, #DSEG7_OUTPUT{\n\tfont-size:18px;\n\tmargin-top:2px;\n\tmargin-bottom:10px;\n}\n\n</style>\n\n\n<div class=\"Clock-Wrapper center lcdClock\">\n\t<span class=\"Clock-Time-Background D7MBI\">88:88<span style=\"font-size:30px;\">88</span></span>\n\t<span id=\"DSEGClock\" class=\"Clock-Time-Front D7MBI\"></span>\n\t<span class=\"Clock-Year-Background\"><span class=\"D7MI\">2088-88-88</span><span class=\"D14MI\"> ~~~</span></span>\n\t<span id=\"DSEGClock-Year\" class=\"Clock-Year-Front\"></span>\n\t\n\t<span id=\"DSEGTemp\" class=\"temp D7MBI\">41</span>\n\t<span id=\"DSEGTemp\" class=\"tempBack D7MBI\">88</span>\t\n\t<span id=\"DSEGTempc\" class=\"tempc D7MI\">C</span>\n\t<span id=\"DSEGTempc\" class=\"tempcBack D7MI\">8</span>\t\n</div>\n\n","storeOutMessages":true,"fwdInMessages":false,"resendOnRefresh":false,"templateScope":"local","x":360,"y":260,"wires":[[]]},{"id":"e796e59c.744638","type":"inject","z":"6bc50f94.1dba4","name":"21c","topic":"","payload":"21","payloadType":"num","repeat":"","crontab":"","once":false,"x":150,"y":241,"wires":[["4c49dd26.cee034"]]},{"id":"5a75cabc.dd548c","type":"inject","z":"6bc50f94.1dba4","name":"32c","topic":"","payload":"32","payloadType":"num","repeat":"","crontab":"","once":false,"x":150,"y":281,"wires":[["4c49dd26.cee034"]]},{"id":"25c161.b26d26a","type":"inject","z":"6bc50f94.1dba4","name":"green","topic":"","payload":"green","payloadType":"str","repeat":"","crontab":"","once":false,"x":150,"y":340,"wires":[["f9c1154a.88a4b8"]]},{"id":"4885793e.0d1cd","type":"inject","z":"6bc50f94.1dba4","name":"orange","topic":"","payload":"orange","payloadType":"str","repeat":"","crontab":"","once":false,"x":150,"y":380,"wires":[["f9c1154a.88a4b8"]]},{"id":"f9c1154a.88a4b8","type":"function","z":"6bc50f94.1dba4","name":"","func":"msg.colour=msg.payload;\nmsg.payload=undefined;\nreturn msg;","outputs":1,"noerr":0,"x":300,"y":360,"wires":[["4c49dd26.cee034"]]},{"id":"254f1cd.ac04a64","type":"inject","z":"6bc50f94.1dba4","name":"blue","topic":"","payload":"blue","payloadType":"str","repeat":"","crontab":"","once":false,"x":150,"y":420,"wires":[["f9c1154a.88a4b8"]]},{"id":"331593f1.7a3964","type":"inject","z":"6bc50f94.1dba4","name":"yellow","topic":"","payload":"yellow","payloadType":"str","repeat":"","crontab":"","once":false,"x":150,"y":460,"wires":[["f9c1154a.88a4b8"]]},{"id":"3e1abe0b.adb2f2","type":"inject","z":"6bc50f94.1dba4","name":"white","topic":"","payload":"white","payloadType":"str","repeat":"","crontab":"","once":false,"x":150,"y":500,"wires":[["f9c1154a.88a4b8"]]},{"id":"a39faec2.3fc6e","type":"inject","z":"6bc50f94.1dba4","name":"pink","topic":"","payload":"pink","payloadType":"str","repeat":"","crontab":"","once":false,"x":150,"y":540,"wires":[["f9c1154a.88a4b8"]]},{"id":"624b007c.9d0ec","type":"inject","z":"6bc50f94.1dba4","name":"red and light text","topic":"","payload":"red","payloadType":"str","repeat":"","crontab":"","once":false,"x":180,"y":580,"wires":[["f9c1154a.88a4b8"]]},{"id":"af432f5b.089378","type":"inject","z":"6bc50f94.1dba4","name":"","topic":"","payload":"","payloadType":"date","repeat":"15","crontab":"","once":false,"onceDelay":"1","x":150,"y":40,"wires":[["8ac49fa9.3f8a48"]]},{"id":"8ac49fa9.3f8a48","type":"rpi-dht22","z":"6bc50f94.1dba4","name":"","topic":"rpi-dht22","dht":22,"pintype":"0","pin":"17","x":360,"y":40,"wires":[["94602188.46f148","3af49491.9103a4","328bc58e.c747ca","4c49dd26.cee034"]]},{"id":"94602188.46f148","type":"function","z":"6bc50f94.1dba4","name":"","func":"msg.payload = msg.payload\nreturn msg;","outputs":1,"noerr":0,"x":510,"y":80,"wires":[["b6914c51.b585b8"]]},{"id":"3af49491.9103a4","type":"function","z":"6bc50f94.1dba4","name":"","func":"msg.payload = msg.humidity\nreturn msg;","outputs":1,"noerr":0,"x":530,"y":200,"wires":[["c3ba06f5.bb37e"]]},{"id":"328bc58e.c747ca","type":"debug","z":"6bc50f94.1dba4","name":"","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":660,"y":40,"wires":[]},{"id":"b6914c51.b585b8","type":"debug","z":"6bc50f94.1dba4","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":680,"y":120,"wires":[]},{"id":"c3ba06f5.bb37e","type":"debug","z":"6bc50f94.1dba4","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":680,"y":200,"wires":[]},{"id":"72cdc2ca.9d9cec","type":"ui_group","z":"","name":"Group 3","tab":"f6671a4d.05349","order":3,"disp":false,"width":15,"collapse":false},{"id":"f6671a4d.05349","type":"ui_tab","z":"","name":"Lab","icon":"dashboard","order":1,"disabled":false,"hidden":false}]

```

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [15 June 2020 13:34 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/4 "2020-06-15T13:34:43Z")

</div>

In javascript you can use toFixed() to do it.

---

<div class="post-metadata">

**Author:** ![colint](https://avatars.discourse-cdn.com/v4/letter/c/8dc957/32.png) [@colint](https://discourse.nodered.org/u/colint)\
**Post date:** [15 June 2020 13:56 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/5 "2020-06-15T13:56:33Z")

</div>

> [@Colin](#):
>
> toFixed()

could you give me an example?

for temperature i use:

msg.payload = msg.payload  
return msg;

---

<div class="post-metadata">

**Author:** ![E1cid](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/e1cid/32/77971_2.png) [@E1cid](https://discourse.nodered.org/u/E1cid)\
**Post date:** [15 June 2020 15:46 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/6 "2020-06-15T15:46:06Z")

</div>

[https://www.w3schools.com/jsref/jsref\_tofixed.asp](https://www.w3schools.com/jsref/jsref_tofixed.asp)

This will only work if your temp is a number i.e. 27.30.  
But if as i suspect your value is a string i.e. "27.30 celcius".  
Then you will need to convert your string.

[https://www.w3schools.com/jsref/jsref\_number.asp](https://www.w3schools.com/jsref/jsref_number.asp)  
[https://www.w3schools.com/jsref/jsref\_split.asp](https://www.w3schools.com/jsref/jsref_split.asp)

---

<div class="post-metadata">

**Author:** ![colint](https://avatars.discourse-cdn.com/v4/letter/c/8dc957/32.png) [@colint](https://discourse.nodered.org/u/colint)\
**Post date:** [15 June 2020 16:13 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/7 "2020-06-15T16:13:19Z")

</div>

i do not understand.  
could you look into my flow and edit the functions after the dht22?

---

<div class="post-metadata">

**Author:** ![E1cid](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/e1cid/32/77971_2.png) [@E1cid](https://discourse.nodered.org/u/E1cid)\
**Post date:** [15 June 2020 17:09 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/8 "2020-06-15T17:09:54Z")

</div>

What is the output of the debug, as until i am sure of the format, i can not know how to convert it

`num.toFixed(2); ` the example from the link i provided  
num would be your variable msg.payload, if it is a number.  
If msg.payload is a string it will not work.

---

<div class="post-metadata">

**Author:** ![Brew](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/brew/32/19776_2.png) [@Brew](https://discourse.nodered.org/u/Brew)\
**Post date:** [15 June 2020 19:16 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/9 "2020-06-15T19:16:27Z")

</div>

Hi there,

I'm using a DHT22 and this is what I'm doing

 ![Screenshot 2020-06-15 at 19.14.01](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/3/1/31b31cc6b98c322e402f216105d12c92ff9045d2.png)

```auto
[{"id":"67621562.f1efb4","type":"rpi-dht22","z":"28c74192.7f20a6","name":"","topic":"rpi-dht22","dht":"22","pintype":1,"pin":"7","x":260,"y":500,"wires":[["8a15fcfc.974bd","97ce4fe6.079298","ca83d5bc.246f2"]]},{"id":"67f52941.db908","type":"inject","z":"28c74192.7f20a6","name":"","topic":"","payload":"","payloadType":"date","repeat":"60","crontab":"","once":true,"onceDelay":"","x":110,"y":500,"wires":[["67621562.f1efb4"]]},{"id":"8a15fcfc.974bd","type":"ui_gauge","z":"28c74192.7f20a6","name":"","group":"539ac07a.3da428","order":1,"width":0,"height":0,"gtype":"gage","title":"Loft Temperature","label":"units","format":"{{value}}","min":"-5","max":"45","colors":["#00b500","#e6e600","#ca3838"],"seg1":"","seg2":"","x":470,"y":500,"wires":[]},{"id":"97ce4fe6.079298","type":"function","z":"28c74192.7f20a6","name":"Humidity","func":"return { payload : msg.humidity };","outputs":1,"noerr":0,"x":440,"y":460,"wires":[["8927bb8e.17d8c8"]]},{"id":"8927bb8e.17d8c8","type":"ui_gauge","z":"28c74192.7f20a6","name":"","group":"539ac07a.3da428","order":2,"width":0,"height":0,"gtype":"gage","title":"Humidity","label":"","format":"{{value}}","min":"20","max":"60","colors":["#00b500","#e6e600","#ca3838"],"seg1":"","seg2":"","x":620,"y":460,"wires":[]},{"id":"ca83d5bc.246f2","type":"function","z":"28c74192.7f20a6","name":"Combine temp/humd","func":"msg.payload = {\n date: new Date().toString(),\n temperature: msg.payload,\n humidity: msg.humidity\n};\nreturn msg","outputs":1,"noerr":0,"x":480,"y":540,"wires":[["7531671b.26603","cbd3ac9.96813d"]],"info":"From Andy"},{"id":"8b8c8fc1.25bb18","type":"comment","z":"28c74192.7f20a6","name":"External Sensor","info":"","x":100,"y":460,"wires":[]},{"id":"7531671b.26603","type":"debug","z":"28c74192.7f20a6","name":"","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":690,"y":500,"wires":[]},{"id":"539ac07a.3da428","type":"ui_group","z":"","name":"Loft","tab":"17237dd7.1f3f42","order":3,"disp":true,"width":"6","collapse":false},{"id":"17237dd7.1f3f42","type":"ui_tab","z":"","name":"Rpi Health","icon":"dashboard","disabled":false,"hidden":false}]

```

I've then got a couple of Function nodes to turn the string value into a number

> msg.payload = parseFloat(msg.payload);  
> return msg;

The nugget you probably need is the Math.round() function  
[https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global\_Objects/Math/round](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/round)

I use it to round to two decimal places

```str
var x = parseFloat(str);
x = Math.round(x*100)/100;
msg.payload = x
return msg;

```

![Screenshot 2020-06-15 at 20.15.48](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/6/6/66e513672e7e9568fb1919c343fab3b51e70005f.png)  
Hope this helps.

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [15 June 2020 20:19 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/10 "2020-06-15T20:19:46Z")

</div>

> [@Brew](#):
>
> `x = Math.round(x*100)/100;`

Rather than using round you can use toFixed() which is a little simpler.

```auto
var x = parseFloat(str);
msg.payload = x.toFixed(2)
return msg;

```

---

<div class="post-metadata">

**Author:** ![Brew](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/brew/32/19776_2.png) [@Brew](https://discourse.nodered.org/u/Brew)\
**Post date:** [15 June 2020 20:31 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/11 "2020-06-15T20:31:23Z")

</div>

Nice one, much cleaner.

---

<div class="post-metadata">

**Author:** ![colint](https://avatars.discourse-cdn.com/v4/letter/c/8dc957/32.png) [@colint](https://discourse.nodered.org/u/colint)\
**Post date:** [16 June 2020 10:33 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/12 "2020-06-16T10:33:48Z")

</div>

> [@Brew](#):
>
> ```auto
> var x = parseFloat(str);
> x = Math.round(x*100)/100;
> msg.payload = x
> return msg;
> 
> ```

this is what the dht22 is sending  
{"\_msgid":"4b5035d7.5cecdc","topic":"rpi-dht22","payload":"23.90","humidity":"58.80","isValid":true,"errors":0,"sensorid":"dht22"}

when i use toFixed or Math solutions i am getting errors like:

- ReferenceError: str is not defined (line 1, col 20)
- TypeError: msg.payload.toFixed is not a function

---

<div class="post-metadata">

**Author:** ![dynamicdave](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dynamicdave/32/96_2.png) [@dynamicdave](https://discourse.nodered.org/u/dynamicdave)\
**Post date:** [16 June 2020 10:53 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/13 "2020-06-16T10:53:43Z")

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I think you are missing this line at the start of your function block.

```auto
var str = msg.payload;

```

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<div class="post-metadata">

**Author:** ![Brew](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/brew/32/19776_2.png) [@Brew](https://discourse.nodered.org/u/Brew)\
**Post date:** [16 June 2020 10:55 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/14 "2020-06-16T10:55:53Z")

</div>

No sorry this is what I'm using after passing the info to another Rpi to spit what is a string out into numbers. it's the Str\>Num Function

 ![Screenshot 2020-06-16 at 11.53.25](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/2/2/22b1e5eb158a7452a89286ce14dcdd77908ee4d5.png)

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<div class="post-metadata">

**Author:** ![colint](https://avatars.discourse-cdn.com/v4/letter/c/8dc957/32.png) [@colint](https://discourse.nodered.org/u/colint)\
**Post date:** [16 June 2020 11:56 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/15 "2020-06-16T11:56:25Z")

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> [@Colin](#):
>
> ```auto
> var x = parseFloat(str);
> msg.payload = x.toFixed(2)
> return msg;
> 
> ```

Guy, super thanks!

my first funcyion after DHT22 is:

```auto
msg.payload = msg.payload;
return msg;

```

The second function is:

```auto
var str = msg.payload;
var x = parseFloat(str);
msg.payload = x.toFixed(1)
return msg;

```

and this gives me the temperature with 1 decimal.

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<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [16 June 2020 12:37 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/16 "2020-06-16T12:37:05Z")

</div>

Your first function does absolutely nothing (other than consume a bit of processor time). You don't need it.  
When people post flows for you to use please make sure that you understand what they are doing. That way you learn much more. If you don't understand something then ask.

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [30 June 2020 12:37 UTC](https://discourse.nodered.org/t/help-with-dht22-and-values/28359/17 "2020-06-30T12:37:10Z")

</div>

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