Can''t Communicate. Help.
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Posts: 46,084
Hi
You say you connected DTR straight to ATN, right? I do not
recommend this as it causes you trouble if DTR is held in the
wrong state (and holding the stamp in reset state). Use a capacitor
between DTR and ATN, e.g.:
100nF
DTR
||---+
ATN
|
_|_100nF
---
|
GND
Check the level on your stamp's ATN pin, if it is high this means that
the stamp is hold in reset state. The forementinned circuit avoids
this situation - and improves noise resistance besides that.
One thing more: 12V nominal (17V effective) to Vin is quite a lot,
I suggest to reduce it to something between 7V and 9V effective to
lower the stress on the stamp's internal regulator.
Regards
Adrian
You say you connected DTR straight to ATN, right? I do not
recommend this as it causes you trouble if DTR is held in the
wrong state (and holding the stamp in reset state). Use a capacitor
between DTR and ATN, e.g.:
100nF
DTR
||---+
ATN
|
_|_100nF
---
|
GND
Check the level on your stamp's ATN pin, if it is high this means that
the stamp is hold in reset state. The forementinned circuit avoids
this situation - and improves noise resistance besides that.
One thing more: 12V nominal (17V effective) to Vin is quite a lot,
I suggest to reduce it to something between 7V and 9V effective to
lower the stress on the stamp's internal regulator.
Regards
Adrian