Hi guys

I need to design a timer circuit that turn off the light/load at 11 pm and turn it on on 5am, I am thinking using a RCT and a MCU, as this is what I am comfortable with, but is there a better way that I don't know?

• It will need to adjust the time according to day light saving, but this is not an must have function.
• under 1mA power consumption as this is powered by battery.

the purpose of this little circuit is to lower energy consumption of the battery.

Thanks guys

edit:

If I have to use a RTC with a MCU, how do you usually set the time, do you set the time when assemble the circuit, or design an easy to use interface with it and let the user set the time.

 

i would want to be able to set the time. this means either having local interface (keypad + display, dial switches, touchscreen whatever...) or remote (pc program or app on the phone for example).

 

To set my RTCs, I usually invite a bunch of people over for New Year's Eve every leap year and, just at midnight, I ask everyone to install a battery into a project I have built in the previous four years.

It works like a charm. You just have to be careful if some of your friends (or spouses friends) are not very technical and do things like get the battery in backwards or finish their conversation, or, worst of all, feel the need to kiss their significant other as the clock strikes twelve. I usually give those people projects that don't actually have RTCs but just let them play along with the rest of the adults.

 

Hi guys

I need to design a timer circuit that turn off the light/load at 11 pm and turn it on on 5am, I am thinking using a RCT and a MCU, as this is what I am comfortable with, but is there a better way that I don't know?

• It will need to adjust the time according to day light saving, but this is not an must have function.
• under 1mA power consumption as this is powered by battery.

the purpose of this little circuit is to lower energy consumption of the battery.

Thanks guys

edit:

If I have to use a RTC with a MCU, how do you usually set the time, do you set the time when assemble the circuit, or design an easy to use interface with it and let the user set the time.

I set the time with software whenever I change the battery, which isn't very often, because most of the time my RTC runs off a wall wart. A CR2032 lasts for years.

 

http://1000bulbs.com/product/56821/...BaseShopping&gclid=CIKLvOimorUCFcpDMgodthMAnQ
I have used these with good results, They automatically adjust for DST.

 

http://1000bulbs.com/product/56821/...BaseShopping&gclid=CIKLvOimorUCFcpDMgodthMAnQ
I have used these with good results, They automatically adjust for DST.

Hi Meixner,

It might be the one I need, do you happen to know the power consumption? I have a quick look but didn't find any infomation on it.

Thanks