If I ground the DQ pin I get all 1's. When I attach DQ to the pic I get a Raw reading of 170. The problem is its still at 170 after several minutes in the freezer. I'm thinking its dead.
|
If I ground the DQ pin I get all 1's. When I attach DQ to the pic I get a Raw reading of 170. The problem is its still at 170 after several minutes in the freezer. I'm thinking its dead.
|
I know this is an old post - but I though I might add what I discovered as it might help someone else in this position.
I had a similar situation using Bruce Reynolds demo code. After a load of time spent trying a whole lot of stuff including swapping sensors I found this -
When the DS18B20 is running in Parasitic Power mode (ie VCC input is tied to GND) then it cannot pull the DQ line high to notify the conversion is in progress.
I reconnected the Vcc on my DS18B20 to +5 and now it runs like a charm.
Hope this helps someone else !
Bill.
Last edited by bcd; - 10th June 2007 at 07:24.
|
BTW my sensor turned out to be dead.New sensor, same code...all was well.
Members who have read this thread : 0You do not have permission to view the list of names.
Posting Permissions
Bookmarks