WiSnap User Manual 4.41 05282015-ML
Page 5
Apply 3.3 VDC power to VBATT (pin 20), and V3.3IN (pin 21).
Tie 3.3VREG-IN (pin 18) to GROUND.
Leave 3.3V-REG-OUT (Pin 17) floating/no connect.
BATTERY:
Apply battery = 2.0 to 3.3VDC to VBATT (pin 20). Leave V3.3IN pin 21 floating/no connect.
Tie pin 17 to pin 18. (This enables the on board battery boost 3.3V switcher).
There is a built in voltage brownout monitor which will shut down the chip when the voltage drops below 2.0 VDC.
Warning: Do NOT exceed these voltage ratings or damage to the module will occur!
NOTES:
1)
The Sensor inputs SENS0-7 are extremely sensitive to over voltage. Under no conditions should these pins
be driven above 1.2VDC. Placing any voltage above this will permanently damage the radio module and
render it useless.
2)
Placing 5VDC or any voltage above 3.3VDC into the VDD pins of the module will permanently damage the
radio module.
3)
Placing 3.3VDC into the PIO’s while they are set as outputs will permanently damage the module. The failure
mode is a short across GND and VCC.
2.1.2 WiSnap AAA Dongle
The WiSnap AAA Dongle is powered by two AAA batteries, an external AC to 5VDC power cable, or
5VDC (only) on pin 9 of the DB9 connector. Rechargeable NiMH batteries will be trickle charged when used with an external
5VDC (only) power source.
The power cable is center pin positive, outer cylinder GND. Input
MUST be 5 VDC
for proper battery charging. Higher
voltages can permanently damage the charger and battery.
NOTE:
Although external power is possible, batteries MUST BE CONNECTED in order to complete the circuit. Without
batteries, permanent damage to the unit may result.
WARNING: Do NOT use alkaline batteries while connecting any external power source. Doing so will cause
permanent damage. If you desire to run off AC or external DC power, this can be accomplished by inserting NiMH
re-chargeable batteries.
Charging is a trickle charge; it typically takes 10 hours to charge batteries fully from low battery. The charge rate of the charger
is low enough (< 100ma) such that the batteries can be charged indefinitely with no harm to them.
In configuration mode the
show bat
command will return the current battery voltage. Note that with rechargeable NiMh
batteries, the voltage will remain relatively unchanged until they go dead.
2.2 Reset
NOTE:
The following only applies to the WiSnap M1 module.
Reset is active LOW and is optional/does not need to be connected. The reset pin is 3.3V tolerant and has an internal pull up of
100K to the VBATT.
2.3 UART
