DHT22 not giving correct results

Hello all-
I'm using Jonnymac's jm_dht11_demo spin file with a dht22( I believe I read on a thread that his spin file will read both sensors) and am getting the results in the attached picture. I have a 10K resistor between power and signal. Does anyone have any ideas I can try?

Thanks
Shawn
1366 x 768 - 32K
«1

Comments

  • 38 Comments sorted by Date Added Votes
  • Shawn LoweShawn Lowe Posts: 576
    edited July 2016 Vote Up0Vote Down
    Okay, I'm now using the DHT22 program in the obex by Walter Mosscrop. It is sending out what I would think is more closely accurate results. I will see what I an get from Tachyon, bearing I can get it working.

    Edit- I modified his original program in the OBEX to suit my set up. Program attached.
    '' SPECIAL VERSION FOR TESTING DUE TO VARIANCES IN SENSORS
    '' WTM 01/22/2016
    ''
    ''******************************************
    ''*  Title: DHTnn_Test for DHT11_Object    *
    ''*  Modified from DHT21_Demo -            *
    ''*  Walter T. Mosscrop 2014               *
    ''*  Author: Gregg Erickson  2012          *
    ''*  See MIT License for Related Copyright *
    ''*  See end of file and objects for .     *
    ''*  related copyrights and terms of use   *
    ''*  This object draws upon code from other*
    ''*  OBEX objects such as servoinput.spin  *
    ''*  and DHT C++  from Adafruit Industries *
    ''*                                        *
    ''*  The object reads the temperature and  *
    ''*  humidity from an DHT11 Sensor         *
    ''*  using a unique 1-wire serial protocol *
    ''*  with 5 byte packets where 0s are 26uS *
    ''*  long and 1s are 70uS.                 *
    ''*                                        *
    ''*  The object automatically returns the  *
    ''*  temperature and humidiy to variables  *
    ''*  memory every few seconds as Deg C and *
    ''*  relative percent respectively. It also*
    ''*  return an error byte where true means *
    ''*  the data received had correct parity  *
    ''*                                        *
    ''******************************************
    
    
    
    CON
    
      _clkmode = xtal1 + pll16x   'Set clock speed and mode
      _xinfreq = 5_000_000
    VAR
    
    long ReadStatus      ' Status of available data
                         ' -1 = updating values, try again
                         '  0 = bad data (parity error)
                         '  1 = good data
    long Temperature     ' Calculated temperature in degrees C as float
    long Humidity        ' Calculated humidity in % relative humidity as float
    
    OBJ
    
      serial  : "FullDuplexSerial"
      DHT     : "DHTnn_Object"
      f       : "FloatMath"
      fp      : "FloatString"
    
    Pub Main
    
    serial.start(31, 30, 0, 38_400)     ' Initialize Serial Communication to Serial Terminal
    fp.SetPrecision(4)
    '              pin, device (11 or 22), temperature address, humidity address, read status address
    DHT.StartDHTnn(15  , 12               , @Temperature       , @Humidity       , @ReadStatus) 
    
    repeat
        readStatus := -1
    
        DHT.DHTnn_Read 
    
        repeat until ReadStatus => 0
    
        if ReadStatus == 1
          temperature := f.FMul(temperature, 9.0)    ' Convert °C to °F
          temperature := f.FDiv(temperature, 5.0)
          temperature := f.FAdd(temperature, 32.0)
          
          serial.str(fp.FloatToString(temperature))
          serial.str(@fahr)
          serial.str(@space)
    
          serial.str(fp.FloatToString(humidity))
          serial.str(@percent)
    
          serial.str(@crlf)
    
        else
          serial.str(@invalid)
          serial.str(@crlf)
    
    Dat
                                                    
    Space    byte " ",0           ' Strings for use in printing
    Percent  byte " %",0
    Fahr     byte " F",0
    Valid    byte " Read OK",0
    Invalid  byte " Read Error",0
    crlf     byte $0A, $0D, 0
    
    {{
    
    ┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
    │                                                   TERMS OF USE: MIT License                                                  │
    ├──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
    │Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation    │
    │files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy,    │
    │modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software│
    │is furnished to do so, subject to the following conditions:                                                                   │
    │                                                                                                                              │
    │The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.│
    │                                                                                                                              │
    │THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE          │
    │WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR         │
    │COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,   │
    │ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                         │
    └──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
    }}
    

    That is weird I have 12 instead of 22 and its working. I changed it to 22 with the same results though.
  • Peter JakackiPeter Jakacki Posts: 6,678
    edited July 2016 Vote Up0Vote Down
    If you have a look at Tachyon's EXTEND you will see this comment for the DHT.
    {HELP DHT@ ( pin -- rh temp | -1 )
    Read the relative humidity and temperature from the DHT22
    Return with rh and temp in Celsius
    If an error occurred in the checksum then return last valid reading
    If the sensor is polled more than once every 2 seconds then use last valid readings
    Typical acquisition time ~6ms
    }
    So if you are using pin 15 then just type "15 DHT<cr>" and when you print the first result returned then that's the temperature in Celius*10 and the second item is the humidty *10.
    I just connected up a DHT22 to one of my boards on P16 and this is all I did to test it
    16 DHT   ok
    . 269 ok
    . 401 ok
    16 DHT . 268 ok
    . 395 ok
    16 DHT . SPACE . 266 476 ok
    

    So the first time through I read 269 which is 26.9'C and 401 which is 40.1% RH. Finally after huffing on the sensor I get a reading of 26.6'C and 47.6% RH.

    Not just happy with that I do a quick one-liner and place a cube of ice over the sensor resting on tissue paper:
    BEGIN CR 16 DHT . SPACE . 3 seconds KEY UNTIL
    
    This is what it showed, the temperature dropping and the humidity rising, as it should.
    265 655
    178 340
    175 341
    173 343
    172 344
    170 346
    169 349
    167 352
    166 352
    164 354
    163 356
    162 358
    161 360
    160 362
    159 364
    158 365
    157 367
    156 368
    155 371
    154 372
    153 376
    153 378
    151 379 ok
    

    After a couple of minutes:
    121 454
    119 454
    119 456
    118 456
    118 457
    117 458
    117 459
    117 459 ok
    

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia
  • DHT11 is a little different, here my Tachyon code,
    closely based in @Peter's DHT2 code.
    pub DHT11 ( pin -- rh temp )
     	runtime @ httime @ - 2000 =>				--- don't poll more than once every 2 seconds
     	IF
     	  runtime @ httime !					--- mark runtime when this was polled
     	  htck C~
    	  DUP MASK 3 COGREG! 
    	  DUP LOW 20 ms DUP FLOAT				--- Generate reset pulse
    	  DHTBIT DROP						--- wait for start of response
    	  DHTBIT 3 / 2* htref W!				--- use start bit as reference
    	  DHTBYTE DHTBYTE DROP				--- 2 bytes humidity reading 
    	  DHTBYTE DHTBYTE DROP				--- 2 bytes temperature reading 
    	  htck C@ DHTBYTE = 					--- if checksum does not match then use last reading
     	    IF htsav W! rh W! ELSE 2DROP THEN			--- latch readings if valid
      	THEN
    	DROP rh W@ htsav W@					--- return with latest valid result
    	;
    	
    
    
    pub .DHT11 ( pin -- )
    	DHT11
    	." Temp = " .
    	."  Degrees Celcius RH = " . ." %" CR ;
    	
    
    pub LOOPDHT11 ( pin -- )
    	BEGIN
    		DUP
    		.DHT11 5 seconds
    		KEY
    	UNTIL
    	DROP
    	;
    	
    
    http://www.smmu.info (german) Source-Measure-Multiplex-Unit = professional test system for electronic components, sensors, assemblies
    Tachyon code and documentation snippets from Tachyon thread
  • Peter JakackiPeter Jakacki Posts: 6,678
    edited July 2016 Vote Up0Vote Down
    MJB wrote: »
    DHT11 is a little different, here my Tachyon code,
    closely based in @Peter's DHT2 code.

    Other than 20ms instead of 1ms reset pulse there isn't any real difference except you are only using 8-bits. I've checked the datasheet for the DHT11 and it seems that the data format is the same so I've just allowed for a longer reset pulse for a DHT11 as it doesn't make much sense to have a different driver just for this one small detail.

    DHT11
    5. Communication Process: Serial Interface (Single-Wire Two-Way) Single-bus data format is used for communication and synchronization between MCU and DHT11 sensor. One communication process is about 4ms. Data consists of decimal and integral parts. A complete data transmission is 40bit, and the sensor sends higher data bit first. Data format: 8bit integral RH data + 8bit decimal RH data + 8bit integral T data + 8bit decimal T data + 8bit check sum. If the data transmission is right, the check-sum should be the last 8bit of "8bit integral RH data + 8bit decimal RH data + 8bit integral T data + 8bit decimal T data".

    DHT22
    DHT22 send out higher data bit firstly! DATA=8 bit integral RH data+8 bit decimal RH data+8 bit integral T data+8 bit decimal T data+8 bit check-sum If the data transmission is right, check-sum should be the last 8 bit of "8 bit integral RH data+8 bit decimal RH data+8 bit integral T data+8 bit decimal T data".
    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia
  • Shawn LoweShawn Lowe Posts: 576
    edited August 2016 Vote Up0Vote Down
    Okay, after having fun loading tachyon on my prop I tried your program peter as shown below. I only get zero's. Any ideas?

    Edit: I'm using the latest tachyon and extend builds: tachyon 300_160804 and the extend in the dropbox.

    1366 x 768 - 50K
  • Peter JakackiPeter Jakacki Posts: 6,678
    edited August 2016 Vote Up0Vote Down
    Just grabbed a DHT22, connected it to 5V, put a 1K resistor in the data line back to P24 and it works fine.
    24 DHT . SPACE . 229 474 ok

    Try another I/O pin or DHT22 and always make sure you use a current limit resistor if running from 5V. I notice that many diagrams show a pullup but the one wire that the DHT22 uses is not the same as the "1-wire" bus.

    Testing the DHT22 it shows that internally it has a 4k7 pullup to supply which means that the pullup they show in the datasheet is redundant. The DHT22 works directly from 3.3V so no current limit or pullup resistors are necessary.


    Hint: If you need to post terminal output just copy and paste as code rather than screenshots unless it is something fancy.

    btw, here's a simple routine to sample and display the results:
    pub .DHT ( pin -- )	DHT SPACE 0 1 .DP PRINT" 'C  @" 0 1 .DP PRINT" %rh " ; 
    
    and running it
    24 .DHT  21.3'C  @46.6%rh  ok
    

    Just had a look at how they do it Arduino style and the code is a little more than one line plus it needs floats:
    /* How to use the DHT-22 sensor with Arduino uno
       Temperature and humidity sensor
       More info: http://www.ardumotive.com/how-to-use-dht-22-sensor-en.html
       Dev: Michalis Vasilakis // Date: 1/7/2015 // www.ardumotive.com */
    
    //Libraries
    #include <DHT.h>;
    
    //Constants
    #define DHTPIN 2     // what pin we're connected to
    #define DHTTYPE DHT22   // DHT 22  (AM2302)
    DHT dht(DHTPIN, DHTTYPE); //// Initialize DHT sensor for normal 16mhz Arduino
    
    
    //Variables
    int chk;
    float hum;  //Stores humidity value
    float temp; //Stores temperature value
    
    void setup()
    {
        Serial.begin(9600);
    	dht.begin();
    
    }
    
    void loop()
    {
        //Read data and store it to variables hum and temp
        hum = dht.readHumidity();
        temp= dht.readTemperature();
        //Print temp and humidity values to serial monitor
        Serial.print("Humidity: ");
        Serial.print(hum);
        Serial.print(" %, Temp: ");
        Serial.print(temp);
        Serial.println(" Celsius");
    
    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia
  • There is a possibility that if you have just loaded EXTEND but not reset the Prop then the background timers will not be running. Maybe this is what happened in your case. Always make sure to do this when building a system as DHT has a holdoff function of 2 seconds but that depends upon "runtime" and the background timers. If you try to poll it sooner than what it thinks is 2 seconds then it will return with the last latched value, which in your case might be zero. Nonetheless I have just made a change to DHT to give it its own holdoff timer that can't get messed up with runtime. There's also a .DHT function to poll and display the formatted readings.
    24 .DHT  23.3'C  @52.7%rh  ok
    

    Check the extra notes I previously added to my last post.
    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia
  • MJB wrote: »
    DHT11 is a little different, here my Tachyon code,
    closely based in @Peter's DHT2 code.
    Other than 20ms instead of 1ms reset pulse there isn't any real difference except you are only using 8-bits. I've checked the datasheet for the DHT11 and it seems that the data format is the same so I've just allowed for a longer reset pulse for a DHT11 as it doesn't make much sense to have a different driver just for this one small detail.

    The data format is the same. But the DHT11 always reports the decimal bytes as zeroes (less accurate).


    Tulsa, OK

    My OBEX objects:
    AGEL: Another Google Earth Logger
    DHT11 Sensor

    I didn't do it... and I promise not to do it again!
  • Walt, FYI - the link in your signature to the DHT object is outdated.
    San Mateo, CA
  • There is a possibility that if you have just loaded EXTEND but not reset the Prop then the background timers will not be running. Maybe this is what happened in your case. Always make sure to do this when building a system as DHT has a holdoff function of 2 seconds but that depends upon "runtime" and the background timers. If you try to poll it sooner than what it thinks is 2 seconds then it will return with the last latched value, which in your case might be zero. Nonetheless I have just made a change to DHT to give it its own holdoff timer that can't get messed up with runtime. There's also a .DHT function to poll and display the formatted readings.
    24 .DHT  23.3'C  @52.7%rh  ok
    

    Check the extra notes I previously added to my last post.

    Peter- Just downloaded extend, then verified communication by hitting enter a couple times and getting "ok". Then hit reset on my PPDB, bang, no more communication with prop.
  • Peter JakackiPeter Jakacki Posts: 6,678
    edited August 2016 Vote Up0Vote Down
    Can anybody else help here to find out what's going on with Shawn's board? There is no reason that this should happen. What am I missing?

    BTW, It is quite possible too with V3 JUNO that it may not work with older 32k EEPROM systems as it assumes all systems would have 64k which is the standard these days.
    (I could put a test in there for this to prevent it trying to save ROMs to upper EEPROM if there is only 32k). (DONE)
    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia
  • [

    BTW, It is quite possible too with V3 JUNO that it may not work with older 32k EEPROM systems as it assumes all systems would have 64k which is the standard these days.
    (I could put a test in there for this to prevent it trying to save ROMs to upper EEPROM if there is only 32k). (DONE)[/quote]

    Okay! The PPDB board I'm using only comes with 32K even new!! So I need to get a 64K DIP chip before I continue! Thanks Peter, it never would have occurred!

  • Shawn Lowe wrote: »
    [

    BTW, It is quite possible too with V3 JUNO that it may not work with older 32k EEPROM systems as it assumes all systems would have 64k which is the standard these days.
    (I could put a test in there for this to prevent it trying to save ROMs to upper EEPROM if there is only 32k). (DONE)

    Okay! The PPDB board I'm using only comes with 32K even new!! So I need to get a 64K DIP chip before I continue! Thanks Peter, it never would have occurred!

    [/quote]

    But if you try again with the newer version of EXTEND it will detect the 32k EEPROM and not try to backup the ROMS which you aren't using anyway.

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia
  • How new? That'd be cool if I could. Can't believe parallax doesn't put a 64kb in the ppdb. Thanks for the help always
  • Shawn Lowe wrote: »
    How new? That'd be cool if I could. Can't believe parallax doesn't put a 64kb in the ppdb. Thanks for the help always

    The one I modified immediately after mentioning this problem and then appending a (DONE). Mind you though I haven't checked it on a 32k system as I would have to dig one up plus I'm pretty sure it will work because one of the things that happens when EXTEND is loading is that it does a quick check to see if you have 32k or more so that it can optimize the page size for writing blocks of EEPROM and all I added to SAVEROMS was "ep 128 => 0EXIT" which effectively does an early exit if the page size is smaller as in the case of 32k EEPROMs.

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia
  • Shawn Lowe wrote: »
    How new? That'd be cool if I could. Can't believe parallax doesn't put a 64kb in the ppdb. Thanks for the help always

    The one I modified immediately after mentioning this problem and then appending a (DONE). Mind you though I haven't checked it on a 32k system as I would have to dig one up plus I'm pretty sure it will work because one of the things that happens when EXTEND is loading is that it does a quick check to see if you have 32k or more so that it can optimize the page size for writing blocks of EEPROM and all I added to SAVEROMS was "ep 128 => 0EXIT" which effectively does an early exit if the page size is smaller as in the case of 32k EEPROMs.

    this code says
    ep 128 =
    means 64k
    so your line above would also 0EXIT for 64k EEPROMs ...
    0 $8000 E! $8000 E@ 0 E@ <> IF 128 ELSE 64 THEN		== ep
    
    pub .DEVICE ( adr -- )
     	SWITCH
     	$A0	CASE ep 128 = IF PRINT" 64K" ELSE PRINT" 32K" THEN PRINT"  BOOT EEPROM   " BREAK
    
    http://www.smmu.info (german) Source-Measure-Multiplex-Unit = professional test system for electronic components, sensors, assemblies
    Tachyon code and documentation snippets from Tachyon thread
  • Peter JakackiPeter Jakacki Posts: 6,678
    edited August 2016 Vote Up0Vote Down
    : SAVEROMS
    	ep 128 => 0EXIT
    	" ROMS" U@ @NAMES 3 ANDN ' TACHYON 3 ANDN
    
    For 32k ep = 64 (the eeprom page size) so 64 128 => gives a false or 0 result and exits early.

    Testing this plus confirm my 64k EEPROM has an ep of 128.
    64 128 => . 0 ok
    ep . 128 ok
    
    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia
  • : SAVEROMS
    	ep 128 => 0EXIT
    	" ROMS" U@ @NAMES 3 ANDN ' TACHYON 3 ANDN
    
    For 32k ep = 64 (the eeprom page size) so 64 128 => gives a false or 0 result and exits early.

    Testing this plus confirm my 64k EEPROM has an ep of 128.
    64 128 => . 0 ok
    ep . 128 ok
    

    sorry - the 0EXIT trap again ... :-(

    0EXIT === NOT IF EXIT THEN

    http://www.smmu.info (german) Source-Measure-Multiplex-Unit = professional test system for electronic components, sensors, assemblies
    Tachyon code and documentation snippets from Tachyon thread
  • MJB wrote: »
    : SAVEROMS
    	ep 128 => 0EXIT
    	" ROMS" U@ @NAMES 3 ANDN ' TACHYON 3 ANDN
    
    For 32k ep = 64 (the eeprom page size) so 64 128 => gives a false or 0 result and exits early.

    Testing this plus confirm my 64k EEPROM has an ep of 128.
    64 128 => . 0 ok
    ep . 128 ok
    

    sorry - the 0EXIT trap again ... :-(

    0EXIT === NOT IF EXIT THEN
    :) - no worries, always good to spit it out.

    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia
  • MJBMJB Posts: 967
    edited August 2016 Vote Up0Vote Down
    MJB wrote: »
    : SAVEROMS
    	ep 128 => 0EXIT
    	" ROMS" U@ @NAMES 3 ANDN ' TACHYON 3 ANDN
    
    For 32k ep = 64 (the eeprom page size) so 64 128 => gives a false or 0 result and exits early.

    Testing this plus confirm my 64k EEPROM has an ep of 128.
    64 128 => . 0 ok
    ep . 128 ok
    

    sorry - the 0EXIT trap again ... :-(

    0EXIT === NOT IF EXIT THEN
    :) - no worries, always good to spit it out.
    @Peter

    btw. I like the
    " ROMS" U@
    trick :-)

    ... now everybody else than you can find out, what this trick is ;-) and maybe learn s.th.
    http://www.smmu.info (german) Source-Measure-Multiplex-Unit = professional test system for electronic components, sensors, assemblies
    Tachyon code and documentation snippets from Tachyon thread
  • BTW, anyone know where I can order a one off 64K EEPROM dip?
  • MJBMJB Posts: 967
    edited August 2016 Vote Up0Vote Down
    http://www.smmu.info (german) Source-Measure-Multiplex-Unit = professional test system for electronic components, sensors, assemblies
    Tachyon code and documentation snippets from Tachyon thread
  • Shawn Lowe wrote: »
    BTW, anyone know where I can order a one off 64K EEPROM dip?

    Mouser. Drop in replacement:

    http://www.mouser.com/ProductDetail/Microchip-Technology/24LC512-I-PG/?qs=sGAEpiMZZMuVhdAcoizlRSvfTHyGQYYpbLAyXVdZPQc=



    Infernal Machine
  • Peter, et al
    Okay peter solved my problems with communications after reset - thank you! Now everytime I reset or hit ctrl-b I get
    VER:    Propeller .:.:--TACHYON--:.:. Forth V3.0 JUNO 300160804.1730
    PCB:    UNKNOWN (0)
    FREQ:   80MHZ (PLLEN OSCEN XTAL1  PLL16X)
    NAMES:  $5AFE...74D0 for 6,610 bytes (+3,981)
    CODE:   $0930...3755 for 11,813 bytes (+8,085)
    RAM:    9,129 bytes free
    BUILD:  FIRMWARE BUILD DATE 160804:180000   BOOTS:  4   runtime 41
    BOOT:   EXTEND.boot
    MODULES LOADED:
    17C0: EXTEND.fth          Primary extensions to TACHYON kernel - 160809-1840
    ROMS
    ----------------------------------------------------------------
      ok
      ok
    pub .DHT ( pin -- )      DHT SPACE 0 1 .DP PRINT" 'C  @" 0 1 .DP PRINT" %rh " ;   ok
      ok
      ok
    14 .DHT
    

    But when I enter the pub .DHT and tachyon says okay, I enter 14 .DHT (I moved the data line to 14 from 15) I get no response and the propeller hangs. I have this hooked o 3.3V so I have no 1k resistor.
  • Peter JakackiPeter Jakacki Posts: 6,678
    edited August 2016 Vote Up0Vote Down
    Shawn Lowe wrote: »
    Sweet! Thanks for the link

    Don't use that part, it is 64 k bit EEPROM, not 64 k BYTE. Normally k bits are written as kb and k bytes as kB (or KB) but beware the typos accidental or not. The link though that Publison gave is correct although there are many others too. A 64KB part will normally have a 512 as part of its part number to indicate 512k bits or 64k x8 whereas the old standard 32kB was a 24LC256 or 256 k bit EEPROM.

    But as I said before you don't need 64kB normally, it is only if you going to be using those "ROMS" or extend Tachyon to the point with FAT32 and perhaps Ethernet that you need the upper 32kB for the dictionary.

    btw, the problem with the DHT22 could be a faulty DHT and the code hangs waiting for a response. Do a "14 DHT? PRINT" to check the DHT22 which will return with a -1 for yes and a 0 for no. (I favor using the PRINT alias in place of the dot symbol since the dot gets lost or may be interpreted as a full stop etc). Default radix should be decimal but just in case force it with a # prefix like this: #14 or #P14

    If it looks faulty then just post a photo of the the way the sensor is connected up.
    1 VDD
    2 DATA
    3
    4 GND
    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia

  • btw, the problem with the DHT22 could be a faulty DHT and the code hangs waiting for a response. Do a "14 DHT? PRINT" to check the DHT22 which will return with a -1 for yes and a 0 for no. (I favor using the PRINT alias in place of the dot symbol since the dot gets lost or may be interpreted as a full stop etc). Default radix should be decimal but just in case force it with a # prefix like this: #14 or #P14

    If it looks faulty then just post a photo of the the way the sensor is connected up.
    1 VDD
    2 DATA
    3
    4 GND

    Ahem, I uh found the problem with my setup. During playing I removed the wire from the 3.3v to the breadboard *ahem*

    :innocent:

    Here is the ouput now:
    29.5'C  @56.5%rh
     29.6'C  @55.4%rh
     29.5'C  @54.4%rh
     29.4'C  @53.9%rh
     29.3'C  @53.7%rh
     29.2'C  @53.5%rh
     29.2'C  @53.7%rh
     29.0'C  @53.6%rh
     29.0'C  @53.8%rh
     28.8'C  @53.8%rh
     28.8'C  @53.8%rh
     28.6'C  @53.9%rh
     28.6'C  @54.1%rh
     28.5'C  @54.1%rh
     28.4'C  @54.0%rh  ok
    

    Thanks Peter for all the patience!! lol so as a learning experiment how would I convert the Celsius to Fahrenheit in the one liner example?

    BTW, its good to know my sensor is good! Which was the original point of this thread.
  • Shawn Lowe wrote: »
    Thanks Peter for all the patience!! lol so as a learning experiment how would I convert the Celsius to Fahrenheit in the one liner example?

    BTW, its good to know my sensor is good! Which was the original point of this thread.

    Take 100'C and convert to F interactively
    100 9 * 5 / 32 + . 212
    
    So you see if you multiply by 9 divide by 5 and then add 32 you have F. Make this a function.
    pub C>F ( c -- f ) 9 * 5 / 32 + ;
    
    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia
  • Forgot about scaled output of sensor so add 320 instead
    Tachyon Forth - compact, fast, forthwright and interactive
    useforthlogo-s.png
    Tachyon Forth News Blog
    TACHYON DEMONSTRATOR
    Brisbane, Australia
  • He he he heeee-
    Playing this is what I'm getting:
     Propeller .:.:--TACHYON--:.:. Forth V3.0 JUNO 300160804.1730
    
    VER:    Propeller .:.:--TACHYON--:.:. Forth V3.0 JUNO 300160804.1730
    PCB:    UNKNOWN (0)
    FREQ:   80MHZ (PLLEN OSCEN XTAL1  PLL16X)
    NAMES:  $5AFE...74D0 for 6,610 bytes (+3,981)
    CODE:   $0930...3761 for 11,825 bytes (+8,097)
    RAM:    9,117 bytes free
    BUILD:  FIRMWARE BUILD DATE 160804:180000   BOOTS:  12   runtime 41
    BOOT:   EXTEND.boot
    MODULES LOADED:
    17C0: EXTEND.fth          Primary extensions to TACHYON kernel - 160809-1840
    ROMS
    ----------------------------------------------------------------
    pub c>f 9 * 5 / 320 + ;  ok
    pub .dht dht space c>f 0 1 .dp print" 'F @" 0 1 .dp print" %rh " ;  ok
      ok
    14   ok
    begin cr 14 .dht 3 seconds key until
     73.0'F @66.6%rh
     73.7'F @66.6%rh
     73.7'F @66.6%rh
     73.7'F @66.5%rh
     73.7'F @66.5%rh
     73.7'F @66.5%rh
     73.7'F @68.3%rh
     74.1'F @87.2%rh
     74.6'F @92.3%rh
     75.2'F @93.5%rh
     75.7'F @94.0%rh
     76.2'F @94.0%rh
     76.8'F @93.3%rh
     77.3'F @81.5%rh
     77.5'F @72.2%rh
     77.9'F @66.5%rh
     78.0'F @64.6%rh
     78.0'F @63.6%rh
     78.2'F @62.8%rh
     78.2'F @62.3%rh  ok
    

    Does tachyon have graphing capabilities? This is pretty cool!
Sign In or Register to comment.