hi all i thought i would post a update on how my main project is going.... a quick recap.
the project is to fully automate comercial type incubators and although them to be indevidualy setup with different paramaters depending on A. what species there incubating and B. whether the unit is being used to incubate or hatch eggs.
For the prototypes i have set up 2 test units (1. incubator 2. hatcher). theese units physicaly look nothing like the incubator units that will be used but have the same parameters such as insulation proterties etc as the final units. the main difference is size, the test units hold approx 250-350 eggs each while the finished comercial units will hold approx 600-800 eggs each.
at present the heating is supplied by way of light bulbs (2x100W with 2x100W as backup), theese will be replaced with a heating element or cable once the tempreture control unit is complete.
the eggs are on "racks" in 5 layers, the warm air is distributed to each layer via 3 rows of 3 fans each (9 in total). currently the heating and tempreture control is being handled by a comercial 4 channel unit using DS18s20 sensors (K190unit), this unit is controlled via rs232 to a pc and software written for the K190. three of the four tempreture channels also control each row of fans (On & Off).
the main fan control is via a fan control unit wich consists of a 28 pin pic (18f2585), this unit uses software pwm to vary the speed of each individualy fan in a variable pattern (currently set by a include file). the unit works well and alows fine tuning of heating rates and humidity. future development of this unit will include linking it to humidity measurment and having the fan speed and pattern altered according to tempreture and humidity.
note. the software for the fan control unit hasnt been written by me so i will not be posting the code (sorry)
Watch Dog Unit
This unit is currently based on a 40 pin pic (18f4685) and is in prototype phase so the chip may well change, the units main functions are.
1. to monitor light output from the heating bulbs and to switch in a back up bulb when a main heating bulb fails (this happens approx 3 times over a 3 week period!), this is achieved by using a LDR on each of the bulbs, when the light level drops the unit checks the k190 heating unit to see if the heater is meant to be on or off, if it is in a off condition then no action is taken, however if the k190 returns a on condition and no light output is detected then the unit switches in a back up bulb.
2. monitors the pc status,
we have frequent small powerouts (<5mins) and sometimes the pc dosnt restart properly or dosnt restart at all wich renders the k190 useless, so the WDU monitors the pc power and parralell port if the power is on but the port isnt providing signal pulses it will restrt the pc, or if the pc is off it will restrt it.
3. the unit also monitors the power supplies for the pics and the the relays etc if any of theese supplies fail it alarms and switches in a back up.
4 the unit is also connected to a LCD wich displays each the different systems status and any fault conditions that exist.
this unit is working very well as a protype unit but is currently having a a few redesign features added and the software is undergoing a exstensive rewrite, main points regarding software for this unit is i am going to add a menu system and self test function i will also add a RTC and usart function so i can log the data via RS232 on the pc.
Humidity unit
this is the newest unit i am working on and is currently in BB prototype phase.
Like most of the units i use it has started life on a 40 pin pic (18f4685) but will eventualy be moved to eigther a 18 pin chip (18f1330) or a 28 pin chip (18f2685). for the senors i am using sensiron SHT71 sensors, theese measure bith tempreture and humidity although its mainly the humidity reading from them that i am interested in. i have yet to decide wether i will be using 1 or 3-4 sensors per incubator (or hatcher). currently i have a BB set up that monitors 1 sensor. the origanal driver i wrote was working fairly well but i have found a better driver that was written for a different compiler and have converted it to work with C18, i have also added usart so the tempreture, humidity and Dew Point are output to the pc for logging, i have also added a LCD where the tempreture and humidity are displayed, presently i am rewriting the software so it will monitor,display and log data from 3 sensors, the end aim at this point will be to have the unit adjust both humidity levels via a water resivouir systems and to alter the main fan unit speed and pattern according to layer humidity readings. it will also control dry air input fans and stale air exhaust fans via hardware pwm. i have included a photo of the early bread board version of the humdity sensor, ignore the messy board and the fact there is etc components not being used on the board, like i said it was a very early protype!!
anyway i hope you enjoyed the update! the next one will include some software as soon as i have tiedied it up a little!!
**broken link removed**