This is my very first project with a PICAXE.
I am very impressed of the simplicity of the handling of this little system!
This is a timer for up to 48 hours, which is used to shut off a dryer for shoes after the chosen time.
The hardware consists of:
1. Mains power supply with a converter that gives the power and a 50Hz timer signal. The power for the relay is not stabil.
2. A FET-driver for the relay and the relay.
3. A two colour LED to give feedback of the remaining time.
4. A reset switch (short cut) and a potentiometer to start the timer and to have input for the time.
The software consists of
1. Reading the potentiometer and calculating the desired time, which is nonlinear to have fine adjustment for short times.
2. The time counter (down) which is interrupt driven from the 50Hz signal. – I don’t know, if sometimes some impulses are lost, but for times of about one minute it seemed to work correct. And for this application this is not critical.
3. The relay is not simply switched but the pwm output is used for lower power consumption. At the start the “on-percentage†is higher than for the long remaining “on†time.
4. Time signal using the two colour LED.
• First the green led blinks n times
• Then the red led blinks f times f stands for a factor which is 1*, 5* or 25*
• Third the green led blinks one time for minutes and two times for hours.
• Example: 2 blinks green, 2 blinks red, 2 blinks green stands for: 2*5= 10 Minutes left.
Has anyone other good ideas showing a number with blinking lights?
Have fun with the picaxe.
21.10.2007 CWE
I am very impressed of the simplicity of the handling of this little system!
This is a timer for up to 48 hours, which is used to shut off a dryer for shoes after the chosen time.
The hardware consists of:
1. Mains power supply with a converter that gives the power and a 50Hz timer signal. The power for the relay is not stabil.
2. A FET-driver for the relay and the relay.
3. A two colour LED to give feedback of the remaining time.
4. A reset switch (short cut) and a potentiometer to start the timer and to have input for the time.
The software consists of
1. Reading the potentiometer and calculating the desired time, which is nonlinear to have fine adjustment for short times.
2. The time counter (down) which is interrupt driven from the 50Hz signal. – I don’t know, if sometimes some impulses are lost, but for times of about one minute it seemed to work correct. And for this application this is not critical.
3. The relay is not simply switched but the pwm output is used for lower power consumption. At the start the “on-percentage†is higher than for the long remaining “on†time.
4. Time signal using the two colour LED.
• First the green led blinks n times
• Then the red led blinks f times f stands for a factor which is 1*, 5* or 25*
• Third the green led blinks one time for minutes and two times for hours.
• Example: 2 blinks green, 2 blinks red, 2 blinks green stands for: 2*5= 10 Minutes left.
Has anyone other good ideas showing a number with blinking lights?
Have fun with the picaxe.
21.10.2007 CWE