SI7021 boards
-
@m26872 I found both SI7021 on Aliexpress.com
@GertSanders Link?
-
Not SI7021 directly, but there are a lot of small sized I2C sensors.
I use a BME280 board on my gateway and on a node.
I also use a BH1750 (slightly bigger) outside to track plants sun exposure.If you end up with a design where the I2C bus is included I can definitively see a lot of uses for it!
-
@GertSanders Link?
-
Without LDO, but with pull up resistors (smallest board I could find):
http://www.aliexpress.com/item/Industrial-High-Precision-Si7021-Humidity-Sensor-with-I2C-Interface-for-Arduino/32524005324.html -
Without LDO, but with pull up resistors (smallest board I could find):
http://www.aliexpress.com/item/Industrial-High-Precision-Si7021-Humidity-Sensor-with-I2C-Interface-for-Arduino/32524005324.html@GertSanders and @AWI Thanks!
-
@Carl-H it's a possibility. No plans yet, other projects ongoing.
-
I just received some si7021 boards from china. They are with LDO and level shifter, similar to
http://www.aliexpress.com/item/Si7021-Industrial-High-Precision-Humidity-Sensor-with-I2C-Interface-for-Arduino/32529522264.html
(the original offer went offline, it was from a reseller named "home boutique", no idea why they sold this item)
If I use them with a battery node, is it sufficient to remove (and short-cut) the LDO or do I need to remove the level shifter too? -
I just received some si7021 boards from china. They are with LDO and level shifter, similar to
http://www.aliexpress.com/item/Si7021-Industrial-High-Precision-Humidity-Sensor-with-I2C-Interface-for-Arduino/32529522264.html
(the original offer went offline, it was from a reseller named "home boutique", no idea why they sold this item)
If I use them with a battery node, is it sufficient to remove (and short-cut) the LDO or do I need to remove the level shifter too? -
I just received some si7021 boards from china. They are with LDO and level shifter, similar to
http://www.aliexpress.com/item/Si7021-Industrial-High-Precision-Humidity-Sensor-with-I2C-Interface-for-Arduino/32529522264.html
(the original offer went offline, it was from a reseller named "home boutique", no idea why they sold this item)
If I use them with a battery node, is it sufficient to remove (and short-cut) the LDO or do I need to remove the level shifter too?@fleinze I am using ATmega328 with 1Mhz and with LDO i have 15uA in standby mode. I have removed the LDO and measured 8uA. You should try it yourself.
-
I just received some si7021 boards from china. They are with LDO and level shifter, similar to
http://www.aliexpress.com/item/Si7021-Industrial-High-Precision-Humidity-Sensor-with-I2C-Interface-for-Arduino/32529522264.html
(the original offer went offline, it was from a reseller named "home boutique", no idea why they sold this item)
If I use them with a battery node, is it sufficient to remove (and short-cut) the LDO or do I need to remove the level shifter too?@fleinze I wrote a few words about it over here http://forum.mysensors.org/topic/3049/slim-node-si7021-sensor-example/
-
-
-
@fleinze The 662k on this board has a typical drop-out of 250mV and power consumption of only 1uA... and takes care of a stable power supply. I doubt if there is any advantage in bridging or removing the LDO.
662k
si7021
@AWI What happens when the input voltage drops below 3.1V ? It seems the output voltage just follows the input voltage minus the dropout. I have not measured this yet, but I'm assuming this, since i have nodes working below 3.1V and sending temperature and humidity readings.
-
@AWI What happens when the input voltage drops below 3.1V ? It seems the output voltage just follows the input voltage minus the dropout. I have not measured this yet, but I'm assuming this, since i have nodes working below 3.1V and sending temperature and humidity readings.
@GertSanders No conclusive reading from the datasheet. I will do some measurements later. ..
Hello! It looks like you're interested in this conversation, but you don't have an account yet.
Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.
With your input, this post could be even better 💗
Register Login