Parallax BASIC Stamp 2e, Programming Manual

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5: BASIC Stamp Command Reference – NAP
BASIC Stamp Programming Manual 2.0c
•
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•
Page 191
NAP
BS1 BS2 BS2e BS2sx BS2p
NAP Period
Function
Enter sleep mode for a short period. Power consumption is reduced as
indicated in Table 5.41 assuming no loads are being driven.
•
Period
is a variable/constant/expression (0 – 7) that specifies the
duration of the reduced-power nap. The duration is (2^Period) * 18
ms. Table 5.42 indicates the nap length for any given Period.
Quick Facts
BS1 BS2 BS2e BS2sx BS2p
Current draw
during run
2 mA 8 mA 25 mA 60 mA 40 mA
Current draw
during NAP
20 µA 40 µA 60 µA 60 µA 60 µA
Accuracy of
NAP
–50 to 100%
(±10% @ 75
°
F
with stable
power supply)
–50 to 100%
(±10% @ 75
°
F
with stable
power supply)
–50 to 100%
(±10% @ 75
°
F
with stable
power supply)
–50 to 100%
(±10% @ 75
°
F
with stable
power supply)
–50 to 100%
(±10% @ 75
°
F
with stable
power supply)
Explanation
NAP uses the same shutdown/startup mechanism as SLEEP, with one big
difference. During SLEEP, the BASIC Stamp automatically compensates
for variations in the speed of the watchdog timer oscillator that serves as
its alarm clock. As a result, longer SLEEP intervals are accurate to
approximately ±1 percent.
Period Length of Nap
0 18 ms
1 36 ms
2 72 ms
3 144 ms
4 288 ms
5 576 ms
6 1152 ms (1.152 seconds)
7 2304 ms (2.304 seconds)
NAP intervals are directly controlled by the watchdog timer without
compensation. Variations in temperature, supply voltage, and
manufacturing tolerance of the BASIC Stamp's interpreter chip can cause
1 2
e
2
sx
2
p
2
1
NOTE: Expressions are not
allowed as arguments on the BS1.
Table 5.41: NAP Quick Facts.
Note: Current measurements are
based on no extra loads at 75
°
F.
Table 5.42: Period and Resulting
Length of NAP.
NAP
ACCURACY NOTES
.