urn:uuid:214d0e4e-f1b1-d287-ce26-ac5b4c9f8249 2017-07-14T11:05:20-06:00 SparkFun Electronics Shadar urn:uuid:2636fe5c-e6cd-f3e5-ddef-9adfa09174f3 2016-12-19T16:50:10-07:00 <p>Just a quick note on the library. The hookup guide says that pressure is returned in kilopascals, but unless I&rsquo;m deep under the ocean and nobody told me, it&rsquo;s just returning pascals.</p> Customer #835092 urn:uuid:76d97918-97ee-a2d7-d5c0-1570985ba43d 2016-09-14T12:13:47-06:00 <p>These boards aren&rsquo;t compatible with 5 volts. I had several sensors burn out due to being connected to I2C on a MEGA 2560 without level shifting before I figured this out. See the BME 280 absolute ratings in the datasheet&hellip; it states Vdd and Vddio maximum is 4.25V and interface pins maximum is Vddio + 0.3V.</p> Customer #772155 urn:uuid:8e418ee9-c321-248a-42f4-f75663bc8369 2016-02-17T08:11:26-07:00 <p>I love how easy this device was to set up, and the built-in I2C/SPI support, but I, too, am finding the temp readings from this device to be consistently high, sometimes by as much as 9 degrees F. I have it connected via I2C directly to an ESP8266 thing (WRL13231), with the BME280 board hanging off the edge so it doesn&rsquo;t pick up heat from the thing, and I have two other thermometers sitting right next to it. The temps all rise and fall together, but the BME280 is between 5 and 9 degrees (F) high. The thing should be delivering 3.3v, so I don&rsquo;t think it&rsquo;s over voltage, and it&rsquo;s in a fairly breezy outdoor location so I also don&rsquo;t think it&rsquo;s surrounded by heated air. This is so far off I&rsquo;m tempted just to call it defective or miscalibrated and order a replacement. It&rsquo;s a shame we can&rsquo;t somehow fix the calibration by taking known temps.</p> Customer #17552 urn:uuid:12ea6220-ed7d-5b8c-7d6d-c57e2ebaa710 2016-01-29T16:16:41-07:00 <p>Is there a Particle Spark library for this module?</p> Customer #749205 urn:uuid:06f00c25-89b6-d9f9-ca92-9e7e72faeddc 2015-12-09T03:37:28-07:00 <p>I can confirm, that readings seems to be high compared to other I2C sensors. Since all available BME280 libraries give similar results i assume, there could be a misinterpretation of calibration values or a not yet discovered problem with the datasheet. I set up a small test on 3.3V bus with readings all 15s.</p> <pre><code>----------START----------197177 BME280 Temp: 22.94 BMP180 Temp: 21.30 HTU21D Temp: 21.55 AM2321 Temp: 21.50 BME280 Pres: 966.81 hPa BMP180 Pres: 968.24 hPa BME280 Hum: 46.13 HTU21D Hum: 51.46 AM2321 Hum: 49.70 </code></pre> MTaylor urn:uuid:03725f1f-9c32-e816-9275-7d923a7a4306 2015-12-03T14:44:40-07:00 <p>Hey everyone. There&rsquo;s a few comments here that have to do with the sensor being a few degrees high and I wanted to discuss it.</p> <h4>Specified Accuracy</h4> <p>I looked up datasheets on the various sensors this is being compared to. Here&rsquo;s the take-away:</p> <p><strong>TMP36:</strong> Specified accurate to +-2 degrees C <strong>DHT11:</strong> Specified +-2 degrees C <strong>MPL3115A2:</strong> +-1 degree C at 25C +-3 degrees C over full range <strong>BME280:</strong> +-0.5 degree C at 25C +-1 degrees C over full range</p> <p>So, by manufacturer specification the BME280 is the most accurate.</p> <h4>Implementation Impact</h4> <p>Some of the discussion says that maybe the location in the circuit effects the temperature. Noting that self-heating could possibly effect the temperature, I devised a quick experiment to test this.</p> <ul> <li>Two boards are configured in I2C, on the same bus. One has a fan to circulate room air.</li> <li>One board is configured as SPI and <strong>overvolted</strong> to 5.0 V (I connected to uno-type with no level shifter)</li> <li>Two boards are left out as control</li> <li>Temperatures measured by the sensor and by a this <a href="https://www.sparkfun.com/products/10830" rel="nofollow" >IR Thermometer</a>. The samples were measured up against the face of the IR hole, centered.</li> </ul> <p>Here&rsquo;s the test data:</p> <p><a href="https://cdn.sparkfun.com/assets/learn_tutorials/4/1/9/experiment_overview.jpg" rel="nofollow" ><img src="https://cdn.sparkfun.com/r/600-600/assets/learn_tutorials/4/1/9/experiment_overview.jpg" rel="nofollow" alt="Experiment photo showing EUTs" /></a></p> <h4>Conclusion</h4> <ol> <li>The BME spec. is tighter than most of the complaints' test thermometer.</li> <li>Implementation had &lt;1 deg. C impact on the various sensors. In any of these configurations, the IR thermometer read very similarly. This is surprising for the over-volt case where the extra voltage could result in extra self-heating in the sensor, but it doesn&rsquo;t measure as such.</li> <li>Over-volting the SPI bus causes an incorrectly high reading of about 3 degrees</li> <li>(not shown in data) Returning sample 3 to an appropriate 3.3 V bus restores correct operation</li> <li>Handling boards causes them to rise 2-5 degrees C. Thermal equalization of that difference takes about 5 minutes.</li> </ol> <p>-MTaylor</p> jmclaughlin urn:uuid:cee00f6d-cb9f-671c-ac74-6de26b27b99f 2015-12-03T07:42:02-07:00 <p>Chiming in because I have the same problem! Consistently reading 2.5C to 3C warmer than actual (as measured with a TMP36, and a wall thermometer.)</p> <p>Temp from my TMP36 sensor: 21.29C</p> <p>Temp from BME280: 23.94C</p> <p>Calibration words and first reading from BME280:</p> <pre><code>Displaying concatenated calibration words dig_T1, uint16: 28229 dig_T2, int16: 26576 dig_T3, int16: 50 dig_P1, uint16: 38175 dig_P2, int16: -10690 dig_P3, int16: 3024 dig_P4, int16: 3748 dig_P5, int16: 3 dig_P6, int16: -7 dig_P7, int16: 9900 dig_P8, int16: -10230 dig_P9, int16: 4285 dig_H1, uint8: 75 dig_H2, int16: 356 dig_H3, uint8: 0 dig_H4, int16: 333 dig_H5, int16: 0 dig_H6, uint8: 30 Temperature: 23.94 degrees C Temperature: 75.07 degrees F Pressure: 96380.00 Pa Altitude: 434.37m Altitude: 1425.11ft %RH: 25.00 % </code></pre> datacute urn:uuid:2239264f-3c8f-3117-659b-81920d0785cd 2015-12-01T02:43:27-07:00 <p>I also have one of these that is giving temperature readings that are 4.25 degrees too high.</p> <pre><code>Displaying concatenated calibration words dig_T1, uint16: 28281 dig_T2, int16: 26448 dig_T3, int16: 50 dig_P1, uint16: 36891 dig_P2, int16: -10832 dig_P3, int16: 3024 dig_P4, int16: 6098 dig_P5, int16: 80 dig_P6, int16: -7 dig_P7, int16: 9900 dig_P8, int16: -10230 dig_P9, int16: 4285 dig_H1, uint8: 75 dig_H2, int16: 356 dig_H3, uint8: 0 dig_H4, int16: 333 dig_H5, int16: 0 dig_H6, uint8: 30 </code></pre> <p>I&rsquo;m reading 28.40 degrees C instead of 24.7 (inside temperature shown on a weather station console)</p> <p>However that&rsquo;s when plugged into headers on an ESP8266 Thing. When I instead place it at the end of a 30cm cable, the temperature difference comes down to within half a degree of my other reading.</p> <pre><code>Temperature: 24.95 degrees C Temperature: 76.91 degrees F Pressure: 101919.00 Pa Altitude: -51.02m Altitude: -167.37ft %RH: 46.00 % </code></pre> <p>My elevation is about 30m above see level, not 50m beneath it. However the pressure at sea level at the moment is not 1013.25 hPa as the library assumes. Adafruit&rsquo;s BME280 library takes the unknown current sea level pressure as an input to the altitude function.</p> PointyOintment urn:uuid:eac2c5de-3b38-9d5d-c386-ded2e0118f8d 2015-11-28T22:45:52-07:00 <p>The datasheet says condensation is allowed, but I don&rsquo;t know if immersion will damage the sensor (or the breakout board).</p> PointyOintment urn:uuid:1eefcc98-b451-ac55-6656-7d93b17b4d28 2015-11-28T22:45:10-07:00 <p>The datasheet says its humidity drift is typically 0.5%/year.</p> Customer #486364 urn:uuid:6f243463-6488-9b2c-1abb-a52794480fd2 2015-11-21T12:07:00-07:00 <p>Could be a very simple question. Is this water resistant? I have a PVC rain tower. I want to know what the RH is inside. Obviously the board will get wet. I will use heat shrink on the wiring.</p> mattproc urn:uuid:fe1bebb6-2d49-6c0b-a40a-42a62e59d423 2015-11-13T09:51:31-07:00 <p>that&rsquo;s good news!</p> MoviesColin urn:uuid:4f86b58d-5044-6236-23ad-f24c6c5ee0dd 2015-11-11T12:54:40-07:00 <p>Hey, thanks for the quick response! I appreciate you adding it to the github.</p> makerblog.at urn:uuid:91f69f56-28e2-69ac-9f91-9a7608ab8971 2015-11-11T11:44:23-07:00 <p>Hi Taylor, thanks for your reply, my calibration words are like this:</p> <pre><code>Displaying concatenated calibration words dig_T1, uint16: 28196 dig_T2, int16: 26476 dig_T3, int16: 50 dig_P1, uint16: 37109 dig_P2, int16: -10699 dig_P3, int16: 3024 dig_P4, int16: 5537 dig_P5, int16: 2 dig_P6, int16: -7 dig_P7, int16: 9900 dig_P8, int16: -10230 dig_P9, int16: 4285 dig_H1, uint8: 75 dig_H2, int16: 352 dig_H3, uint8: 0 dig_H4, int16: 344 dig_H5, int16: 0 dig_H6, uint8: 30 </code></pre> <p>Today the temp is only about 2,5 degrees too high (measured with a DHT11 and a MPL3115A2) and altitude about 110m too low. Very strange. I just removed all other components from the breadboard, but still the same&hellip;</p> MTaylor urn:uuid:0b0cefe8-f564-9e25-1977-c90a4c675e86 2015-11-11T10:59:14-07:00 <p>There is! We&rsquo;re working to get our Fritzing parts included with the program but we&rsquo;re not there yet. I&rsquo;ve gone ahead and added the part to the product github, which you should be able to download through github&rsquo;s web interface (or you can clone)</p> <p><a href="https://github.com/sparkfun/SparkFun_BME280_Breakout_Board/tree/master/Fritzing" rel="nofollow" >https://github.com/sparkfun/SparkFun_BME280_Breakout_Board/tree/master/Fritzing</a></p> MoviesColin urn:uuid:bebbe91e-8898-df3b-85da-931eee34f13b 2015-11-10T22:31:18-07:00 <p>Is there a Frizting file available for this? I can&rsquo;t find one, but it looks like the Hook-Up guide is using one.</p> MTaylor urn:uuid:fa7458a0-c234-7868-5989-50177d92d2f6 2015-11-09T12:21:23-07:00 <p>Accuracy should be about +/- 0.5 degrees C, so that&rsquo;s a little odd. Calibration happens from a set of factory programmed registers that the library reads out, then uses for calculations. The barometric readings are highly dependent on temperature, so both being off at the same time isn&rsquo;t so surprising.</p> <p>The I2C_ReadAllData sketch displays the calibration words at the start. Even if you are using SPI (just change the .settings.commInterface and .settings.chipSelectPin lines), can you please send me the concatenated calibration words listing?</p> <p>Mine looks like this:</p> <pre><code>Displaying concatenated calibration words dig_T1, uint16: 27974 dig_T2, int16: 26594 dig_T3, int16: 50 dig_P1, uint16: 38207 dig_P2, int16: -10702 dig_P3, int16: 3024 dig_P4, int16: 7917 dig_P5, int16: -118 dig_P6, int16: -7 dig_P7, int16: 9900 dig_P8, int16: -10230 dig_P9, int16: 4285 dig_H1, uint8: 75 dig_H2, int16: 358 dig_H3, uint8: 0 dig_H4, int16: 328 dig_H5, int16: 0 dig_H6, uint8: 30 </code></pre> <p>Note: start code with 4 spaces for our markdown formatting.</p> makerblog.at urn:uuid:a7b1d7d4-0d23-58dd-eafa-09c988414197 2015-11-09T11:51:45-07:00 <p>I got this breakout board (from a reseller in Germany) but all values are way off. Even the temperature shown by the BME280 is about 3 degrees Celsius higher than the real temperature and altitude is about 130 metres to low. Is there any calibration necessary before first use? I could not find any method for this in the library.</p> M-Short urn:uuid:73b5320b-3845-a7f6-2904-50b1b77fe02e 2015-10-26T09:00:14-06:00 <p>We have started to use a standard on all new boards (which this should follow) because we got sick of the same thing around here. Sometimes you will see additional pins as well, but SCL, SDA, VCC, and GND should all be in the same order on our new boards. We can&rsquo;t force everyone to use our standard, but I have a feeling people are starting to come up with their own anyway.</p> Customer #360923 urn:uuid:509cc2a9-e53f-d373-2699-2afa78c966f4 2015-10-24T08:02:04-06:00 <p>And what about degradation due to permanent humidity (for example in a bathroom)? What do we need to do to protect this Shield against permanent humidity ? Other Humidity sensors (DHT&hellip;) have a life time less than a year before beginning to produce incoherent measurements. The other sensor RB-Dfr-460 seems designed to better resist against moisture in time. In other words , how to use it in a sustainable solution for at least 5 years ?</p> Customer #134773 urn:uuid:84b6d47f-6ee6-bcb1-0e65-a6eed14038fb 2015-10-23T16:10:32-06:00 <p>I, too, agree. I&rsquo;m looking at having this on one end of a &ldquo;flat flexible cable&rdquo; (might try something like a Raspberry Pi camera cable, or might end up using two of the &ldquo;flat coax&rdquo; cables) to put the sensor on the outside of a north-facing window and the computer on the inside of the same window. (Yeah, I&rsquo;ll have to do some weatherproofing, but details, details.) Or maybe I can cobble up a 4-trace cable with some plastic sheet and copper tape. Nice thing about I2C is I only need 4 conductors (pwr, gnd, SDA, SCL)!</p> Customer #134773 urn:uuid:b8e308e5-8abf-880e-66f9-6c5fd808ed13 2015-10-23T16:03:56-06:00 <p>Our friends over at Adafruit seem to have gotten to a standard ordering: Vin (i.e., +5V), 3.3V, GND, SDA, SCL &ndash; most of their boards include a regulator, and are 3.3V logic. (I <em>think</em> I got the order correct, but check the Adafruit website.)</p> mattproc urn:uuid:e4806db1-653c-6353-ed93-aadf7d09f834 2015-10-23T12:41:43-06:00 <p>i know it depends on the part the board is built around, but it kills me that every i2c breakout has the pins in a different order.. it&rsquo;d be so nice to plunk a bunch of them on some stripboard, or to be able to make up a bunch of standard cable assemblies</p> mockd urn:uuid:5a49db7b-58b8-90b6-d2b9-9455ed61b65a 2015-10-23T09:49:40-06:00 <p>Thank you for that. As a user looking at this I want to be able to decide how it is hooked up. Also I have a bunch of headers I can just use anyways.</p> xtopher urn:uuid:13932d43-4e74-989b-abbf-7ac625a0f8a8 2015-10-23T08:34:52-06:00 <p>TheBurrito is completely correct: The main reason why there are no headers per-soldered onto this board is so that you, the end user, get the choice on what sort of connection you want. There are multiple types of headers to choose from, different wires (with and without terminated connectors), and it is a lot easier to solder something on than it is to de-solder that same thing off.</p> <p>If you take a look at our past in-house assemblies you&rsquo;ll notice that most, if not all, of them are sold without headers for this same exact reason. So rest assured that nothing is wrong, we just don&rsquo;t want to make decisions for you that you may not agree with, however, we are sorry for the confusion in this matter. :)</p> TheBurrito urn:uuid:3520e577-75b6-e7d7-295f-2b8673f792b6 2015-10-23T07:55:24-06:00 <p>If everything came with headers I&rsquo;d have a heap of unused headers from soldering wires to my boards. The argument goes both ways and I like the option of getting to choose between headers and wires without clogging up my already overloaded heap &lsquo;o crap.</p> Customer #688987 urn:uuid:aa9c1ace-dbd9-b9e3-81cd-b44bb9f639f4 2015-10-23T07:05:57-06:00 <p>Why doesn&rsquo;t this come with the headers? Even when I order stuff from AliExpress it comes with headers (not pre-soldered of course), and that&rsquo;s like the sketchiest place to order electronics from. I love the idea of this breakout board, but when I have to buy two separate items just to get one physical sensor working somethings wrong&hellip;</p>