Nap - Parallax BASIC Stamp 2e Programming Manual

2
1 2
e
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
5: BASIC Stamp Command Reference – NAP
NAP
2 2 NAP Period
sx p
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
Current draw
during run
Current draw
during NAP
Accuracy of
NAP
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.
approximately ±1 percent.
NAP intervals are directly controlled by the watchdog timer without
compensation.
manufacturing tolerance of the BASIC Stamp's interpreter chip can cause
BS1 BS2 BS2e BS2sx BS2p
BS1 BS2
2 mA 8 mA
20 µA 40 µA
–50 to 100% –50 to 100%
(±10% @ 75°F (±10% @ 75°F
with stable with stable
power supply) power supply)
As a result, longer SLEEP intervals are accurate to
Period Length of Nap
0
1
2
3
4
5
6 1152 ms (1.152 seconds)
7 2304 ms (2.304 seconds)
Variations in temperature, supply voltage, and
BASIC Stamp Programming Manual 2.0c • www.parallaxinc.com • Page 191
BS2e BS2sx
25 mA 60 mA
60 µA 60 µA
–50 to 100% –50 to 100%
(±10% @ 75°F (±10% @ 75°F
with stable with stable
power supply) power supply)
18 ms
36 ms
72 ms
144 ms
288 ms
576 ms
BS2p
40 mA
60 µA
–50 to 100%
(±10% @ 75°F
with stable
power supply)