multiple relative humidity sensors

Question

Hello,
I would like to exchange DS18B20 sensors ligned up on pcb probe by humidity and temperature sensor.
Could you please help to solve that:
-1 every sensor coupled to the common bus line should have its own resistor?
- 2 40cm distance on PCD is ok, or what thickness on PCB is recommendet?
- 3 acquiring data for every of the attached sensor is possible one after the other?
- 4 is atiming of a raspberry pi zero sufficient?
- 5 is sample code in python available?
many thanks
best regards

raja · Answer

HI eff-st ! 
 Thank you for showing interest in Renesas sensor group. Before answering your question, I have a couple of question regarding your project. Could you please tell me the end application of your project in detail? There are two version of Humidity and Temperature sensors like HS300x, HS400x so which one will you be use in your project so that I would understand better your situation? Please go through the attached link for more information regarding humidity sensors. 
 HS4001 - Relative Humidity and Temperature Sensor, Digital Output, &plusmn;1.5% RH | Renesas 
 HS3001 - High-Performance Relative Humidity and Temperature Sensor | Renesas 
 
 Regards: 
 Raja.

raja · Answer

Hi, 
 Thanks for the response. Now replying to your queries: 
 1. Yeah, you can connect multiple target device with one set of pullup resistors. 
 2. Can you more elaborate 40 cm distance meaning it is the distance between sensors or MCU to sensors? 
 3. All the target devices are having same slave address. So, you cannot communicate one by one it will cause error/give incorrect results. To avoid this, you have to add I2C MUX on your board. 
 For more information, I have shared an application note (regarding I2C Mux); please go through it. 
 
 https://www.renesas.com/us/en/products/programmable-mixed-signal-asic-ip-products/greenpak-programmable-mixed-signal-products/greenpak-system-programmability/slg46826-greenpak-programmable-mixed-signal-matrix-system-programmability 
 https://www.renesas.com/us/en/document/apn/cm-285-i2c-bus-multiplexer 
 5. Sample code is not available in python. We have provided sample code that supports Renesas MCU. 
 https://www.renesas.com/us/en/document/scd/hs300x-sample-application-sample-code?r=417401 
 
 4. We would suggest you Use Renesas MCU in your project then we will connect MCU guys to provide better technical support. 
 
 Regards: 
 Raja. 
 
 Regards: 
 Raja.