Hi,
I have just joined this forum as i am looking for some help designing a circuit. My idea is, a mobile phone wired up to phone me when my van gets broken into or even just door opening.
The phone is a fairly simple Nokia 3310. My idea is, having 2 wires soldered to both the cancel button and one of the hot keys to dial the number. the cancel button is to ensure the phone is cleared to allow hot key to work and to cancel and repeat the process. the hot key must be pressed and held for approx 3 seconds to dial.
So what i have thought of so far is, a 555 timer set up as astable with say a 3-4 second delay, connected to a 4017 counter with maybe 2 555s as monostable on 2 outputs, one for .5 seconds for cancel and one for 3 seconds for dial. these could be connected to the first two outputs. The remaining 8 left unconnected. making it a 30 - 40 second cycle including dialing.
to press the buttons i thought relays would work, using the output some how from the 555s to trigger them and close the button circuits. with the rest position (no voltage) on the relays to be open. supply can be from either the 12volt from vehicle or the 3.6 from the phone.
Any recomendations or circuit advise appreciated.
thanks
I have just joined this forum as i am looking for some help designing a circuit. My idea is, a mobile phone wired up to phone me when my van gets broken into or even just door opening.
The phone is a fairly simple Nokia 3310. My idea is, having 2 wires soldered to both the cancel button and one of the hot keys to dial the number. the cancel button is to ensure the phone is cleared to allow hot key to work and to cancel and repeat the process. the hot key must be pressed and held for approx 3 seconds to dial.
So what i have thought of so far is, a 555 timer set up as astable with say a 3-4 second delay, connected to a 4017 counter with maybe 2 555s as monostable on 2 outputs, one for .5 seconds for cancel and one for 3 seconds for dial. these could be connected to the first two outputs. The remaining 8 left unconnected. making it a 30 - 40 second cycle including dialing.
to press the buttons i thought relays would work, using the output some how from the 555s to trigger them and close the button circuits. with the rest position (no voltage) on the relays to be open. supply can be from either the 12volt from vehicle or the 3.6 from the phone.
Any recomendations or circuit advise appreciated.
thanks