This is a complete project.
-Schematic
-Pictures
-Source code
-It was actually built + works
It is a LED light growbox made from 2x Calypso Clear boxes. You could use any kind of cardboard box.
There are various growkits for sale here for low prices, one of which I pictured. These plants typically grow in 2 or 3 months. No plants really like 24 hours light, so you need a timer. Or you need to switch it on/off manually.
-You can place this box on your desktop or at work, maybe there is not enough light to grow plants. And it will be enclosed as well.
-1x white 10W light + 1x red 10W light. A 12V 3A power supply is used. The LEDs have VGA coolers each. They don't turn so hot, the cardboard is not a problem. No screws of any kind are used.
-The timer is based on a PIC 16f1824 but does not really need 4K space. You could use a different chip. A MOSFET is used to switch on/off the LEDs, and it works pretty well, does not heat up much.
-The PIC is powered by a 78L05 and it also does not heat up much. Some 1uF capacitors are added but you could use any.
-Two pushbuttons to set the time, the on-time, and the duration. The time is displayed as hours, 120 second minutes, and 2-second seconds, in binary!
-The mode button will cycle through: Set hours, minutes, on-hours, on-minutes, duration hours, duration minutes, and reset.
-The set button will cycle through from 0 to 31.
-A 32 KHz crystal is used as timebase.
-If there was a power surge, the timer actually will not turn on at all, so you have to check the display sometimes.
-Total costs are about 30 dollar but can depend, it will be higher if you don't have all the materials available. This includes everything!
-The timer just hangs outside the box but can be secured with some bell wire if neccessary. The wires inside are tagged a little with staples.
-I have made a test run. The LEDs work fine and don't overheat. The timer switched on at the programmed time, and off again after the programmed duration elapsed.
-If you build many of these, probably you can build them for less than $30. Yes I know a science laboratory needs $300 for the lamp, and another $200 for the box, and another $200 for the timer and power supply, as well $200 labour costs.
Makes 900 dollar, so if you want 20 boxes, this is going to be expensive research.
It is true if there is a power surge, the programmed time is lost, and the experiment will be ruined
Actually the reason why I have built it was to show it on the internet. You can make a better PCB perhaps, or use some different display. I also use different displays, LCDs, LED 7seg, and I use real timers from a shop.
But the circuit is quite useful, you can use it for just some minutes, or you could modify the program. Then you can switch on/off every few minutes or something like this.
I have chosen a bit of an odd display so if you use it for college your instructor will wonder. As well the schematic is very specific so you need to redraw it. The C source is not commented but if you don't understand how the timer works, it can not be helped for now.
By the way "It can not be helped" is a well known expression in japanese language.
-Schematic
-Pictures
-Source code
-It was actually built + works
It is a LED light growbox made from 2x Calypso Clear boxes. You could use any kind of cardboard box.
There are various growkits for sale here for low prices, one of which I pictured. These plants typically grow in 2 or 3 months. No plants really like 24 hours light, so you need a timer. Or you need to switch it on/off manually.
-You can place this box on your desktop or at work, maybe there is not enough light to grow plants. And it will be enclosed as well.
-1x white 10W light + 1x red 10W light. A 12V 3A power supply is used. The LEDs have VGA coolers each. They don't turn so hot, the cardboard is not a problem. No screws of any kind are used.
-The timer is based on a PIC 16f1824 but does not really need 4K space. You could use a different chip. A MOSFET is used to switch on/off the LEDs, and it works pretty well, does not heat up much.
-The PIC is powered by a 78L05 and it also does not heat up much. Some 1uF capacitors are added but you could use any.
-Two pushbuttons to set the time, the on-time, and the duration. The time is displayed as hours, 120 second minutes, and 2-second seconds, in binary!
-The mode button will cycle through: Set hours, minutes, on-hours, on-minutes, duration hours, duration minutes, and reset.
-The set button will cycle through from 0 to 31.
-A 32 KHz crystal is used as timebase.
-If there was a power surge, the timer actually will not turn on at all, so you have to check the display sometimes.
-Total costs are about 30 dollar but can depend, it will be higher if you don't have all the materials available. This includes everything!
-The timer just hangs outside the box but can be secured with some bell wire if neccessary. The wires inside are tagged a little with staples.
-I have made a test run. The LEDs work fine and don't overheat. The timer switched on at the programmed time, and off again after the programmed duration elapsed.
-If you build many of these, probably you can build them for less than $30. Yes I know a science laboratory needs $300 for the lamp, and another $200 for the box, and another $200 for the timer and power supply, as well $200 labour costs.
Makes 900 dollar, so if you want 20 boxes, this is going to be expensive research.
It is true if there is a power surge, the programmed time is lost, and the experiment will be ruined
Actually the reason why I have built it was to show it on the internet. You can make a better PCB perhaps, or use some different display. I also use different displays, LCDs, LED 7seg, and I use real timers from a shop.
But the circuit is quite useful, you can use it for just some minutes, or you could modify the program. Then you can switch on/off every few minutes or something like this.
I have chosen a bit of an odd display so if you use it for college your instructor will wonder. As well the schematic is very specific so you need to redraw it. The C source is not commented but if you don't understand how the timer works, it can not be helped for now.
By the way "It can not be helped" is a well known expression in japanese language.
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