Dallas 1-wire Crestron CHV-RTHS Sensors

Hi,

My first post, been lurking around for a while.

I Got a handful or these Crestron CHV-RTHS sensors, and need help on getting these to communicate to an Arduino. My thought was easiest method is to use an Arduino Uno and to try and get these talking. Poking around the different components on the circuit board, these sensors communicate over the Dallas 1 wire bus.

These are the sensors:

https://www.crestron.com/Products/Lighting-Environment/Climate-Control/Thermostat-Accessories/CHV-RTHS

These sensors used to be connected as Remote Sensors to a Crestron Thermostat CHV-TSTATA

https://www.crestron.com/getmedia/30fd17db-9731-4919-a517-ca394a7cb967/mg_io_chv-tstat_chv-thstat_1

Looking on Page 8, at the bottom of the CHV-STATA.

All I can see is the Temperature sensor is a DS18B20 and the humidity sensor is "DS2762b" w/ Honeywell HIH-4000 humidity sensor. There is handful of diodes and other ICs on the board, I cannot find any datasheets to figure this sensor out.

The "DS2762b" is a battery monitor that accepts a analog signal from external device, in this case the Honeywell HIH-4000 humidity sensor sends out a analog signal and is wired to the battery monitor, then the "DS2762" I.C. sends this out on the 1 wire bus, and can be wired in parasitic mode requiring only 2 wires for everything.

I cannot find any information and no information is offered by the manufacturer. I'm hoping someone as ran across these sensors, or can assist in figuring out the I.Cs and getting these to talk.

As a last measure, I desoldered a DS18B20 sensor from the PCB and wired it up as described here and sensor works as expected on an Arduino with the Dallas Library.

Here are the pictures of the Sensor. Front and back of the sensor.

Higher Resolution available if you click on the image.

Any help is greatly appreciated.

Bump

Hey I found the Datasheet for the IC which strangely enough is a Maxim Li+ battery monitor but it’s monitoring voltage so I see the connection. DS2762 Datasheet

Google DS2762 with Arduino there are a number of codes and projects. You will have to figure out which pins the sensors are connected to since I don’t have one here.

Check the Maxim code here. It’s written for pic but could be made to work with Arduino. 1 wire code

bump

wolframore:
Hey I found the Datasheet for the IC which strangely enough is a Maxim Li+ battery monitor but it’s monitoring voltage so I see the connection. DS2762 Datasheet

Google DS2762 with Arduino there are a number of codes and projects. You will have to figure out which pins the sensors are connected to since I don’t have one here.

Check the Maxim code here. It’s written for pic but could be made to work with Arduino. 1 wire code

Thanks, I did find the datasheet for the battery monitor, it does show it has external inputs for current sensing is where i'm assuming where the humidity sensor is connected to.

Also, the Maxim Code is the protocol code, Arduino has the Dallas 1 wire library to get the Arduino to talk the protocol, I've got the tools to talk the protocol, but not able to get these particular sensors to talk. I've tried to track down the different ICs on the board, and they are in fact diodes, but that's as far as I got.

Since I don’t have the unit I can only guess but there is a section in the datasheet that has the hardware requirement. Looks like it needs a pull-up between. I’m not sure if this is on the board but I would look at that. If you have an oscilloscope it would be nice to look at the output from the unit.

As far as I am aware Crestron sensors use AC, probably higher voltage than normal too - so I would start digging that way, probably a diode bridge and optoisolators?

Most probably it will be better for you to sell them on eBay to some Crestron guy and buy standard sensors :wink: