18B20 Temerature Sensor (SKU:DFR0024)
kielogl 2013-01-19 18:01:44 4514 Views4 Replies I am having a lot of trouble getting meaningful output from the 18B20 Temperature Sensor (SKU:DFR0024).
It is not clear to me if any external pull-up resistors are needed (wiki pages states "...a couple of resistors and some hookup cables and you're set to go")
Also if it needs to be used in parasite or external supply mode.
Is there a schematic diagram available for the circuit board showing the SMD (470R, 4K7R, etc) connections and how the "A" and "D" pads and other pin holes are meant to be used?
Thanks in advance,
Mark
It is not clear to me if any external pull-up resistors are needed (wiki pages states "...a couple of resistors and some hookup cables and you're set to go")
Also if it needs to be used in parasite or external supply mode.
Is there a schematic diagram available for the circuit board showing the SMD (470R, 4K7R, etc) connections and how the "A" and "D" pads and other pin holes are meant to be used?
Thanks in advance,
Mark
2013-01-23 20:01:02 Hi Kielogl,
The Arduino Due board runs at 3.3V. The maximum voltage that the I/O pins can tolerate is 3.3V. Maybe the voltage is not enough to the sensor .So can you try to use the sensor via Arduino UNO?
Here is the schematic of the 18b20 sensor , hope it is useful for you :)
[url=https://www.dfrobot.com/image/data/DFR0024/18b20%20Schematic.pdf]https://www.dfrobot.com/image/data/DFR0024/18b20%20Schematic.pdf[/url]
Phoebe
The Arduino Due board runs at 3.3V. The maximum voltage that the I/O pins can tolerate is 3.3V. Maybe the voltage is not enough to the sensor .So can you try to use the sensor via Arduino UNO?
Here is the schematic of the 18b20 sensor , hope it is useful for you :)
[url=https://www.dfrobot.com/image/data/DFR0024/18b20%20Schematic.pdf]https://www.dfrobot.com/image/data/DFR0024/18b20%20Schematic.pdf[/url]
Phoebe 2013-01-23 03:09:09 Hi Phoebe,
Thanks for your reply.
I have an Arduino Due. I had some success with the OneWire preview 2.2 and the Dallas Temperature examples, but it seems pretty flakey. It often needs a few resets to detect the device address properly and then only gets a valid reading every 4 or 5 requests. I have two of the sensors and was only able to detect one with both connected to the Due on the same pin.
My main concern was trying to understand how the sensor on-board resistors are wired and if any external resistors are needed before further debugging Due compatibility.
Thanks again,
Mark kielogl
Thanks for your reply.
I have an Arduino Due. I had some success with the OneWire preview 2.2 and the Dallas Temperature examples, but it seems pretty flakey. It often needs a few resets to detect the device address properly and then only gets a valid reading every 4 or 5 requests. I have two of the sensors and was only able to detect one with both connected to the Due on the same pin.
My main concern was trying to understand how the sensor on-board resistors are wired and if any external resistors are needed before further debugging Due compatibility.
Thanks again,
Mark
kielogl 2013-01-22 22:05:51 Hi?kielogl
Sorry for replay late.
Have you ever driver the sensor via the connection diagram & the Sample code in wiki page?
We designed most sensors with the same layerout. So "A" and "D" pads and other pin holes mean nothing?just neglect it.
Phoebe
Sorry for replay late.
Have you ever driver the sensor via the connection diagram & the Sample code in wiki page?
We designed most sensors with the same layerout. So "A" and "D" pads and other pin holes mean nothing?just neglect it.
Phoebe 