On an 16f690, ICSPDAT is RA0, not RB7.

See the datasheet and the schematics in the user guide:

http://ww1.microchip.com/downloads/en/DeviceDoc/Low%20Pin%20Count%20User%20=
Guide%2051556a.pdf

Joep

2010/7/29 Jan-Erik Soderholm <jan-erik.soderholm@telia.com>:
>
> On 2010-07-29 19:55, Joep Suijs wrote:
>> RA0 is also wired to the ICSP connector. I guess you have disconnected
>> the programmer?
>
> I thought about that and specificaly looked for it
> but I can not see that RA0/AN0 is connected to
> the ICSP connector.
>
> The ICSP connector has :
>
> 1: Vdd/Vpp
> 2: Vss
> 3: GND
> 4: ICSPDAT, RB7
> 5: ICSPCLK, RB6
> 6: AUX, RA4
>
> How is RA0/AN0 connected to the ICSP connector ?
>
>
>>
>> Joep
>>
>> 2010/7/29 Jan-Erik Soderholm<jan-erik.soderholm@telia.com>:
>>>
>>>
>>> On 2010-07-29 18:56, alan.b.pearce@stfc.ac.uk wrote:
>>>>> No, just the standard "PICkit2 Starter Kit" :
>>>>> http://www.microchip.com/pickit2/
>>>>>
>>>>> The 28-pin demo board in that kit :
>>>>> http://ww1.microchip.com/downloads/en/DeviceDoc/41301A.pdf
>>>>> Scematic at page 9, the pot at the top of fig A-1.
>>>>>
>>>>> It's the voltage drop over R7 that is my concern.
>>>>>
>>>>>
>>>>> Jan-Erik.
>>>>
>>>> Well, I suspect we are at a point where something in your code is
>>>> setting RA0 to an output and setting it low, i.e. writing 0 to both
>>>> TRISA and PORTA.
>>>
>>> It's not "my" code. :-)
>>>
>>> The code is "lesson 4" in the PICkit2 low-pin-count demo code kit.
>>> I have put a copy of the actual code here :
>>> http://jescab2.dyndns.org/pub_docs/a2d_asm.txt
>>>
>>> I tried to do some minor adjustments (only enabling AN0, shutting
>>> WPU off and so on) but no changes at all.
>>>
>>>
>>>
>>>>
>>>> AIUI having a port bit set to analogue doesn't stop it being used as a
>>>> digital output port. This is used to advantage in some sneaky schemes
>>>> for doing things like making capacitance meters, by discharging the ca=
p
>>>> and then using the A/D or comparator to measure the time it takes to g=
et
>>>> to a certain voltage.
>>>>
>>> --
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>>>
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