Temperature logging interface - Page 1
Forum section: electronics / general

author: IanJ
author_rank: Unknown
timestamp: July 17, 2017, 09:18:00 am
content: Hi all,So I am building a new workshop (for my 3458a, but don't tell her that!)......and have built a PC to use 24/7 with my 3458a GPIB logging spreadsheet (Windows).........but I would also like to log the workshop ambient temp alongside the 3458a data.Any ideas on what to use, I see many USB temperature & humidity loggers on Ebay, but I'd really like one that maybe comes with drivers that allow interfacing via VBA/macro.Any ideas?......PS. Spreadsheet is here:https://www.eevblog.com/forum/metrology/3458a-logging-via-excel-macro/Ian.

author: mimmus78
author_rank: Unknown
timestamp: July 17, 2017, 09:30:12 am
content: Well because you did not went with raspberry, maybe you still can buy one gpio usb board for PC and attach how many bme280 (or other chips) you like.The only problem is I don't know how much is easy to use this gpio boards in Windows.Inviato dal mio Nexus 6P utilizzando Tapatalk

author: alm
author_rank: Super Contributor
timestamp: July 17, 2017, 09:49:33 am
content: Expect cheap eBay hardware to come with software that actually works? That is a tall order. You could use something that implements a CDC (RS-232-like) interface. I imagine you can easily open serial ports in VBA. I might grab a bus pirate with a BME280, but that is not exactly the most elegant solution. At least both the bus pirate and the BME280 are well documented.I am not familiar with hardware access in VBA (I have only used it for automating applications). Can you import arbitrary DLLs? Then an FT232 in I2C mode usingthe FTDI D2XX drivertogether with I2C sensors might be an option.If you want something turnkey, then I would go for the more reputable brands, not random eBay sensors. Sorry, no direct experience, I just stuck a BME280 breakout board on the BBB's GPIO header.

author: IanJ
author_rank: Unknown
timestamp: July 17, 2017, 12:42:35 pm
content: Quote from: Flinstone on July 17, 2017, 10:42:23 amCheers Fred, this looks just the ticket........and the Dev kit software package looks pretty comprehensive enough.http://www.silabs.com/products/development-tools/sensors/si7051-evb-usb-dongle-temperature-evaluation-kithttps://www.silabs.com/documents/public/user-guides/si70xx-temp-and-humidity-sensor-eval-guide.pdfThe tools guide PDF above even gives an Excel example (or it may be an export of data).....but anyways perfect!I've placed an order for a kit, and so once it comes I'll update the Excel Macro logging thread with any changes I make to the spreadsheet to incorporate the temp/humidity logging data.Ian.

author: plesa
author_rank: Frequent Contributor
timestamp: July 17, 2017, 03:33:17 pm
content: What about this. We have support for BME280 and python + web server scripts for plottinghttps://www.eevblog.com/forum/metrology/raspberry-pi23-logging-platform-for-voltnuts/

author: IanJ
author_rank: Unknown
timestamp: July 17, 2017, 04:48:58 pm
content: Quote from: plesa on July 17, 2017, 03:33:17 pmRasp-Pi based?........My setup is Windows only and I wanted to keep it that way. Appreciate the suggestion but I just don't want to go learn another embedded/Linux type system not to mention python. My existing 3458a GPIB logging is via a Windows NI Vesa driver and works pretty good and I just wanted to add to that existing setup. Hopefully I can.Ian.

author: branadic
author_rank: Super Contributor
timestamp: July 17, 2017, 04:50:56 pm
content: Please, don't go for BME280 if you want to do metrology stuff, better use SHT25 and MS5611. You want the best ambient sensors you can get. No problem using Raspberry Pi together with those sensors are any other cheap ass micro with VCP. If you need support just write me a short message.-branadic-

author: IanJ
author_rank: Unknown
timestamp: July 17, 2017, 06:47:36 pm
content: Quote from: Flinstone on July 17, 2017, 06:33:00 pmYup, once i get back into it again I'll look at these.Ian.

author: Muxr
author_rank: Super Contributor
timestamp: July 20, 2017, 07:13:35 pm
content: Quote from: IanJ on July 17, 2017, 04:48:58 pmIf you don't want to use Rpi and just want to use a Windows based PC, the easiest would probably be to use an Arduino board (like an Arduino Nano clone or something) and use serial (over USB).

author: alm
author_rank: Super Contributor
timestamp: July 21, 2017, 09:35:18 am
content: Quote from: branadic on July 17, 2017, 04:50:56 pmCare to elaborate on this? The only references I found on this forum were posts by you without any supporting data. Comparing the data sheets, the SHT25 seems to have marginally better accuracy than the BME280, and the MS5611 seems to have very similar specs to the BME280. The only thing resembling a comparative test I could find (this one) shows the BME280 superior to the Sensirion device. Even if you take the caveat mentioned at the end into account, it is hard to support the conclusion that the Sensirion device is superior, even if the SHT25 performs slightly better than the SHT21.

author: d-smes
author_rank: Regular Contributor
timestamp: July 24, 2017, 12:54:36 pm
content: For temperature, check out TSYS01 (that's a zero in the p/n)http://www.te.com/commerce/DocumentDelivery/DDEController?Action=showdoc&DocId=Data+Sheet%7FTSYS01%7FA%7Fpdf%7FEnglish%7FENG_DS_TSYS01_A.pdf%7FG-NICO-018Max error +/-0.1C over -5C to +50C range.

author: branadic
author_rank: Super Contributor
timestamp: July 24, 2017, 07:19:31 pm
content: QuoteNo data that I can share with the board. Just take the suggestion as it is. The only other hint that I can give you is this link:http://electronics-from-t.blogspot.de/2016/02/lps25h-vs-ms5611-vs-bmp180.htmlIf you want to compare performance then compare to SHT25 original by Sensirion and not some ebay-available copies of this device. If available use the more precise SHT35.-branadic-

author: feedback.loop
author_rank: Frequent Contributor
timestamp: July 25, 2017, 12:54:48 am
content: Quote from: d-smes on July 24, 2017, 12:54:36 pmIt seems to me that Si7051 is cheaper (~$2 vs ~$6.80) and easier to use (6-pin package vs 16-pin) and also 0.1C accuracy.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: July 25, 2017, 02:41:02 am
content: I have used a $30 Texas Instruments development board for their sensor quite successfully. USB interface that looks like a serial port from the PC side. Works fine in VB.I am not sure the absolute accuracy of the sensor is really that critical for the type of metrology uses envisioned here. The sensitivity to temperature of the things being measured is already low so a few tenths of a degree error in temperature will be a small contributor to the overall error.In any case there is likely to be more difficulty in relating the sensor temperature to the temperature of the critical part of the device. Are you interested in the temperature of the air inlet to the instrument, the air near the reference, the reference itself or something else. Each of these locations presents unique problems in coupling the sensor and understanding differences between the sensor temp and "reality".

author: IanJ
author_rank: Unknown
timestamp: September 03, 2017, 10:06:26 am
content: Hi all,I've updated my main 3458a Excel logging page with details of my first attempt at temperature logging.https://www.eevblog.com/forum/metrology/3458a-logging-via-excel-macro/msg1293712/#msg1293712Ian.