Since this project involves THERMISTORS, i've gone to my other tech blog to see what i've done there.
The idea is to make a strip of about 4 or 5 thermistors to hang inside the door of my fridge; i want to see how much colder it is at the bottom compared to the top.
I know it is colder at the bottom, because meat keeps longer there, & sometimes starts to freeze, whereas it never does that nearer the top.
I need some of that ribbon cable to 'insert' the thermistors into, & also to transmit data to the analog pins on my Arduino. i also have a USB power supply, so i could actually do some data-logging over an extended period & save the data to EEPROM for later retrieval & display (& just by chance i've found a LED-strip with about 10 LEDs on it that i'd forgotten i had!).
I'd like to add TWI to a 24LCxx if i can, as that would allow more data to be stored.
A photo-cell (these entries) could tell me when the fridge door was opened.
Another little wrinkle would be to average all the thermistor readings at any one time, & switch on a motor, say, if the average temperature rises above a preset value.
First things first, however: i need to set up the thermistor strip, write the basic software, & get that part working; i can add bells & whistles later.
got a bit mixed up with Polling Routines & the need to suspend timer routines while polling.
ReplyDeleteTWI doesn't require this so i won't have to start/stop TWI while setting a delay between thermistor readings..
however, i don't want to be 'interrupt'ed while actually logging data (stopping in the middle of a TWI cycle is not good for reliablility) so we say:
ReplyDeletenoInterupts()
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..some datalogging software
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interrupts()
spelling (speling!) hehe :-D
ReplyDelete