Tagged Questions

0
votes
0answers
18 views

OneWire DS18B20 on mighty 1284p can't find my sensors, same sensors work w/ Duemilanove

I have uploaded the DS18x20 Temperature example sketch (unaltered, except I tried multiple pins for the I2C communication) to my proven Duemilanove and my ...
0
votes
2answers
147 views

I2C temp sensor and an Arduino wifi shield not working together

I am using an arduino wifi shield and a TMP102 with an arduino uno rev2. With boards older than rev3 you have to add a jumper from the 3.3V to the IOREF pin for the wifi shield, see here: ...
1
vote
1answer
513 views

Soft i2c with Sensirion SHT21 sensors on Arduino Mega

I have tried checking with an oscilloscope on the analogue pins when the sensor is plugged in and I don't seem to get anything as I normally would. The hardware i2c channel works just fine on the ...
0
votes
2answers
381 views

Advice wind direction sensor with I²C interface

I need a wind direction sensor (not anemometer, which is a wind speed sensor) with a high resolution and I²C interface. The only direction sensor I could find were magnetic compasses, that had a very ...
1
vote
2answers
357 views

Reading back 0xffff for temperature from I2C BMP085 temp/pressure sensor

I'm interfacing a Rabbit 5760 CPU to a Bosch BMP085 sensor via I2C. Everything is fine except reading the temperature register is reading back 0xffff (see BP_FINISHTEMP case in switch). I can't see ...
1
vote
1answer
537 views

Advice a humidity sensor with I²C interface

I like to interface a humidity sensor over the I²C bus. It should come in a small package, and consume little power. Accuracy isn't that important. I'm using the DS1621 as temperature sensor, I'd ...
6
votes
2answers
3k views

How do I get an Arduino (5 V) and MPR121 (3.3 V) to talk?

I have the Sparkfun MPR121 I2C Capacitive touch sensor breakout board I have read that it uses 3.3 V, I know that I can't just connect up the 3.3 V power supply output from the Arduino as the ...