SHT30 ARD - Page 1
Forum section: electronics / general

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 06, 2023, 01:58:46 pm
content: Hi, friends!Please help me understand the humidity sensor SHT30-ARD.Sensirion does not have such a sensor or it is very old. Perhaps this is some kind of Chinese version.This sensor is not a SHT30-DIS (have't I2C) and not a SHT30-ARP (have't analog output).When power is applied to it, a short pulse passes to pin 1 and then a sequence of 5.4 seconds duration out to pin 4.What is it and how to decode it?

author: ebastler
author_rank: Super Contributor
timestamp: June 06, 2023, 03:57:01 pm
content: For starters, what indication do you have that such a chip exists?

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 06, 2023, 04:14:52 pm
content: Quote from: ebastler on June 06, 2023, 03:57:01 pmIt's on my desk and works in someone else's system.

author: ebastler
author_rank: Super Contributor
timestamp: June 06, 2023, 04:24:11 pm
content: Quote from: S. Petrukhin on June 06, 2023, 04:14:52 pmI guess I was curious about the exact lettering on the chip, and what the package looks like.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 06, 2023, 04:32:53 pm
content: Quote from: ebastler on June 06, 2023, 04:24:11 pmThe appearance of a regular ST30.The connection is very similar to the SHT30-ARP, but it outputs a digital signal.Inscription:SHT30ARD33PI can take a photo only tomorrow...

author: thm_w
author_rank: Super Contributor
timestamp: June 06, 2023, 09:30:07 pm
content: Is the pulse repeating or only occurs once on startup? If it repeats could be a PWM representation of T and RH.What is connected on pin 1 and 4 in their system, any capacitors, resistors, etc.?

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 06, 2023, 09:41:42 pm
content: Quote from: thm_w on June 06, 2023, 09:30:07 pmIt doesn't look like PWM or SDM, there is no smooth signal of some duty cycle, there is a stream of random bits.The circuit is unknown on the receiving side, both outputs are 10nF capacitors near the sensor.

author: thm_w
author_rank: Super Contributor
timestamp: June 06, 2023, 11:21:18 pm
content: Quote from: S. Petrukhin on June 06, 2023, 09:41:42 pmTo me it wouldn't make sense to have a 10nF capacitor on a data line. That is the recommended circuit for SHT30-ARP analog output version.Maybe the analog output circuitry has been damaged."The first two digits XY (=AR) describe the output mode. The third letter (A) represents the manufacturing year (4 = 2014, 5 = 2015, etc). The last three digits (BCD) represent analphanumeric tracking code. That code can be decoded by Sensirion only and allows for tracking on batch level through production, calibration and testing – and will be provided upon justified request."The part number you gave is for SHT30-ARP.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 06, 2023, 11:29:13 pm
content: Quote from: thm_w on June 06, 2023, 11:21:18 pmYes, I know, I have studied the documentation.This is probably a sensor from another manufacturer.I remember a time when real I2C or full I2C was written in the description of sensors, therefore, before that or sensors with some incomplete I2C. I think it's just him, but I can't find a description for that incomplete I2C.

author: thm_w
author_rank: Super Contributor
timestamp: June 07, 2023, 12:03:31 am
content: Why would another manufacturer use the exact same marking as Sensiron but have different functionality? Doesn't make sense.If the lines are I2C they wouldn't have capacitors, they'd have pullup resistors.You can buy a clone of SHT30-D but its marked as "GX HT30":https://www.micros.com.pl/mediaserver/CZ_SHT30_GX_0001.pdf

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 07, 2023, 11:39:58 am
content: Dear friends!This, however, turned out to be an analog sensor. A strange sequence of bits not similar to PWM or FM transmits exactly the voltage that should be integrated on the capacitor.I was confused by the fact that there is no capacitor and resistor in someone else's circuit, the signal goes directly to the MC pin.There are probably some algorithms for software integration of this signal.Thank you for your participation and help!