MCP3002 10bit AD problem

xanadu

I have an MCP3002 I am trying to interface with the Propeller. I cannot seem to get any output from it, currently I am just looking for a state from a pin and consistently get 0. I'm wondering if I have a bad AD, but don't have any spares to test. Any ideas?

Output (w/3.3v applied to ch1 and ch2 low)

Wait Hi... 0
Wait Lo... 0
Reset Max/Min
Frequency: 0Hz done in 0 samples
Average:   0 average tested with 0 samples
State:     0
Cur Value: 0
Max Value: 0
Min Value: 0

Using this object: http://obex.parallax.com/object/119

I have changed this-

ADC.start(Vo_p, Vn_p, Vclk_p, Vcs_p, 8, 8, 12, 1, false) ' startup the ADC driver (Vo_p and Vn_p can be the same IO pin), 8 channel ADC,
                                                        ' scan all 8 channels, 12-bit ADC, mode 1 (single-ended), and using slow communication

To this-

ADC.start(Vo_p, Vn_p, Vclk_p, Vcs_p, 2, 2, 10, 1, false) ' startup the ADC driver (Vo_p and Vn_p can be the same IO pin), 8 channel ADC,
                                                        ' scan all 8 channels, 12-bit ADC, mode 1 (single-ended), and using slow communication

I'm also using this for inputs-

''* Example wiring would be as follows:                                             *
''*               R1                                                                *
''*     ADC─┳──┳──input                                                         *
''*       C1 R2                                                                 *
''*                                                                               *
''* R1: 10K (high impedance input is helpful, 10K should be the minimum)            *
''* R2: 100K (this effectively creates a voltage divider, but also drives input to  *
''*     zero volts when not in use)                                                 *
''* C1: 0.01µF (10000pF is the about the maximum you would want to use. The         *
''* capacitor reduces jitter or spikes but also reduces resolution).                *

PropGuy2

Here is a code snippet that may help. It I for a 3208 but works great for me. BTW read the spec sheet carefully especially the serial interface timing chart and sample schematics.

xanadu

Thank you, that seems to work fine.

Must be PEBKAC