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Thumb Joystick with Basic Stamp

I'm trying to interface the joystick from Sparksfun with the BS2 , using the RCTIME function.





Using the attached schematic, I'm only able to detect a reading on one side of the joystick (down & right) & nothing on the other side. however, if i connect the Vcc to the Vert & Hor pins, I'm able to detect all four directions. But this also means that I can't use the Select button.


did i miss out something???

Capture.JPG13.15 KB

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Did you check out Parallax info on connecting their similar joystick?

They appear to have the cap connected to ground.   Don't see how any hookup precludes the use of the select, as it should have  a different connection.

 I've checked the similar product from parallax, but it's not working


according to the schematic:

1) Vcc,  Hor, & GND are connected to horizontal pot

2) Vcc, Vert, & GND are connected to vertical pot

3) Sel & GND are connected to selector


for the 2 pots, either Vcc or GND must be connected, but not both. But if i connect Hor & Vert to GND, i can't use the SEL button.

The Sparkfun PCB is setup similar to the second circuit in the Parallax pdf, meaning it is setup to be read by an ADC, not RCtime in the manner of your jpg circuit above. The joystick on the Sparkfun PCB have one side of the pots connected to ground, other side connected to Vcc, with wipers to output, and have the select switch wired to ground.

Instead of connecting Vcc on the Sparkfun board, try the Parallax first circuit, in which the wiper, the outputs Vert and Horz, are connected to a cap with other end to ground, and then to a 220 resistor into a Stamp pin. Connect Sel to another Stamp pin. Do not connect Vcc to the SParkfun PCB. THen run the program from theParallax pdf and check that everything works, adding a line to check the Select button. 

When you make a Stamp pin an input, it should have a weak pull-up that makes that pin high, until the Select button is pus4ed to ground it, making it low.