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Basic Stamp to control a remote control? — Parallax Forums

Basic Stamp to control a remote control?

matt167matt167 Posts: 7
in BASIC Stamp
I have a need for a micro controller to 'push' either an on button or off button dependent on a thermostatic switch of a simple 2 button remote control for a Chinese diesel parking heater..

It's been a few years but I have a little knowledge of the Basic Stamp and have a homework board. I've forgotten a lot of the syntax though. I don't think I need anything more than this and I'm thinking it will be about 3-5 lines of code. It's just an I/O bridge between a home type 24v switching thermostat and this remote control for the parking heater, which operates on a AA battery. I plan to power the remote control board with an external 1.5v regulated source

Will this work as a bridge? my thinking is, the thermostat will act as a button control input. But somehow, the Stamp needs to just 'jump' the switch terminals on the remote. When button ( thermostat calling for heat ) is pressed, it 'pushes' the on button, and then when the thermostat button releases, it pushes the off button

Comments

  • Mike GreenMike Green Posts: 23,101
    A simple reed relay would work well. Digikey has an appropriate one here. Their online catalog gives a price of about $8. The relay coil has the necessary diode across the coil ... make sure the diode is connected properly. You can either connect the relay between an I/O pin and Vss (ground) turning on when the I/O pin is made HIGH or between an I/O pin and Vdd (+5V) turning on when the I/O pin is made LOW. The relay contacts would be connected across the remote control button connections. Unless you want to get "fancy" with the Stamp, you could just use a reed relay without the Stamp. You'd need a 24V coil voltage like this. I think the 24V is AC, so you'd need a diode (like a 1N4001) and electrolytic capacitor to filter the coil voltage to get around 24VDC. I'd use a capacitor rated at least for 35V, maybe 50V. A value of 10uF or 20uF would do. The relay contacts would be across the remote button as before.
  • matt167matt167 Posts: 7
    Mike Green wrote: »
    A simple reed relay would work well. Digikey has an appropriate one here. Their online catalog gives a price of about $8. The relay coil has the necessary diode across the coil ... make sure the diode is connected properly. You can either connect the relay between an I/O pin and Vss (ground) turning on when the I/O pin is made HIGH or between an I/O pin and Vdd (+5V) turning on when the I/O pin is made LOW. The relay contacts would be connected across the remote control button connections. Unless you want to get "fancy" with the Stamp, you could just use a reed relay without the Stamp. You'd need a 24V coil voltage like this. I think the 24V is AC, so you'd need a diode (like a 1N4001) and electrolytic capacitor to filter the coil voltage to get around 24VDC. I'd use a capacitor rated at least for 35V, maybe 50V. A value of 10uF or 20uF would do. The relay contacts would be across the remote button as before.

    Ironically I was just driving home from my works Christmas party and it dawned on me to use a relay for the 'button pressing'.

    I thought about not using a Stamp at all, but would that work to control both an on and an off button? I don't think the electronic programmable type thermostats 'need' 24v to operate. I think if I use the W and R terminals, the battery powered switch will operate to close the input circuit to the stamp.
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