Hi,
I want to make an electronic controller for hydro growers...
The priorities in order are:
* Address *basic* needs of hydro growers, but nothing more
* Cheap
* 'Open' design
* Can be hand-assembled
These are the features I have decided on... comments?
* 'Open' design, all hardware and software design is free. (Except for a more tricky version of software which I charge $ for)
* Free C compiler. At the heart is an Atmel ATMEGA644 microcontroller which has a free C compiler and excellent libraries, so anyone can write software for it.
* All 'through-hole' parts, can be easily assembled by hand
* Vast majority of parts are available at local electronics store or at least an on-line distributor farily cheaply (target prices is US$100 max. not incl probes)
* pH input, can measure pH fron standard BNC connector pH probe to +/- 0.1 pH
* EC input, optimised for sensor constant K=1 but user can vary it (i.e. make your own sensor)
* Humidity, good for 5%, probably 2%
* Light sensor, so you know if your light is on/off/faulty
* Big light switch, 30A resistive, 6A inductive (can probably handle 10A), replaceable with larger external relay
* Fan speed controller, good for 2A (or about 200W on 120V, 400W on 230V)
* 6 x 12A general purpose relays, for things like flood/drain pump, can be wired to do light flip-flop etc
* 6 x general purpose low-voltage digital inputs, for things like float sensors
* 1-wire bus, can add all sorts of stuff, but mostly temperature sensors
* Can plug in a standard 16x2 LCD character display (with backlight) or status LED
* Buzzer
Here is an 'architectural' diagram
I want to make an electronic controller for hydro growers...
The priorities in order are:
* Address *basic* needs of hydro growers, but nothing more
* Cheap
* 'Open' design
* Can be hand-assembled
These are the features I have decided on... comments?
* 'Open' design, all hardware and software design is free. (Except for a more tricky version of software which I charge $ for)
* Free C compiler. At the heart is an Atmel ATMEGA644 microcontroller which has a free C compiler and excellent libraries, so anyone can write software for it.
* All 'through-hole' parts, can be easily assembled by hand
* Vast majority of parts are available at local electronics store or at least an on-line distributor farily cheaply (target prices is US$100 max. not incl probes)
* pH input, can measure pH fron standard BNC connector pH probe to +/- 0.1 pH
* EC input, optimised for sensor constant K=1 but user can vary it (i.e. make your own sensor)
* Humidity, good for 5%, probably 2%
* Light sensor, so you know if your light is on/off/faulty
* Big light switch, 30A resistive, 6A inductive (can probably handle 10A), replaceable with larger external relay
* Fan speed controller, good for 2A (or about 200W on 120V, 400W on 230V)
* 6 x 12A general purpose relays, for things like flood/drain pump, can be wired to do light flip-flop etc
* 6 x general purpose low-voltage digital inputs, for things like float sensors
* 1-wire bus, can add all sorts of stuff, but mostly temperature sensors
* Can plug in a standard 16x2 LCD character display (with backlight) or status LED
* Buzzer
Here is an 'architectural' diagram
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