0
\$\begingroup\$

do anyone help me regarding selecting the sensor, digital temp and humidity in one module and have digital output and one pin connected to micro controller renesas V850 . I have only 3 pins unused. any suggestions please..

\$\endgroup\$
1
\$\begingroup\$

The DHT22 would work: http://www.adafruit.com/products/385

But with three pins on your MCU you could bit bang yourself an I2C bus to connect many other sensors.

\$\endgroup\$
  • \$\begingroup\$ I have 4 digital I/O pins unused and can I apply I2C or SPI protocol with those pins.? if yes how ? or I need another pins? for these types of communication.which communication protocol can I use for DHT22.? \$\endgroup\$ – Renesasuser Jun 13 '14 at 9:18
  • \$\begingroup\$ This is bit banging: en.wikipedia.org/wiki/Bit_banging \$\endgroup\$ – Dejvid_no1 Jun 13 '14 at 9:20
  • \$\begingroup\$ The DHT22 requires no ordinary serial protocol. It uses a pulse timing scheme. Check the datasheet on the page I linked o. \$\endgroup\$ – Dejvid_no1 Jun 13 '14 at 9:21
  • \$\begingroup\$ but I have one more question that already my controller has a lot of applications if I connect 4 DHT22 sensors to the 4 Digital I/O pins and communicate in pulse scheme. does it distrubs any other work done by controller.?? \$\endgroup\$ – Renesasuser Jun 13 '14 at 9:34
  • \$\begingroup\$ You say thanks by selecting my answer... ;) The pulse scheme will probably have an impact on your other code execution. \$\endgroup\$ – Dejvid_no1 Jun 13 '14 at 11:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.