View Single Post
Old 07-31-2012, 10:51 AM   #27 (permalink)
Daox
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 11,166

CM400E - '81 Honda CM400E
90 day: 51.49 mpg (US)

Daox's Grey Prius - '04 Toyota Prius
Team Toyota
90 day: 49.53 mpg (US)

Daox's Insight - '00 Honda Insight
90 day: 64.33 mpg (US)

Swarthy - '14 Mitsubishi Mirage DE
Mitsubishi
90 day: 56.69 mpg (US)
Thanks: 2,464
Thanked 2,535 Times in 1,529 Posts
The other night I borrowed an oscilliscope from work and took a shot at troubleshooting this current sensor issue. I found out the 5V going to the sensor varied a bit, but the vref and output from the sensor were pretty solid (+/- 1mV). I put a capacitor on the 5V input to the sensor and it smoothed things out a bit. I also tried running the arduino off of a 12V battery. Each time the 5V input got a little better, but through the whole thing the sensor output was still very steady.

So, now I am wondering why the arudino is reading a voltage fluxuation on the vref and sensor output pins. According to the serial feedback on the arduino, I'm seeing voltages of 2.519V to 2.539V. The scope showed a pretty consistent 2.513V. So, not only is it showing a voltage fluxuation that isn't there, it is also reading an incorrect voltage.
__________________
Current project: A better alternator delete
  Reply With Quote