RSSI and PDN pins on the 27981 receiver module
billy1180
Posts: 7
Would I be correct using the following methodology in connecting the RSSI pin and the PDN pin. Overall, what I am doing, for the moment, is having two basic stamp 2 modules communicating wirelessly with each other. Each stamp has a 27980 transmitter and 27981 receiver connected to it. To make the algorithm for communication between the two simpler (eventually, the project will go ad-hoc), I would like to turn the receiver off and on via the PDN pin. As for the RSSI pin, I would just like to see the signal strength so I can test the range under different conditions (I understand that is supposed to be 500+ feet in line of sight, but it won't be used in a line of sight application for the most part).
I am thinking that for the RSSI output I need to connect the RSSI pin to a 470 resistor, an LED, and then VSS in series. As for the PDN pin, I would like to think that I can control it with either a HIGH (pin number) or LOW (pin number) command from a Basic stamp I/O pin connected directly to the PDN pin. There may need to be a resistor there to limit the current, but I am not sure and the documentation seems to be a bit sketchy. I only ask as I would rather avoid making a costly mistake by frying either of the rf modules, the stamp itself or the development board. Any help would be greatly appreciated.
Louis
I am thinking that for the RSSI output I need to connect the RSSI pin to a 470 resistor, an LED, and then VSS in series. As for the PDN pin, I would like to think that I can control it with either a HIGH (pin number) or LOW (pin number) command from a Basic stamp I/O pin connected directly to the PDN pin. There may need to be a resistor there to limit the current, but I am not sure and the documentation seems to be a bit sketchy. I only ask as I would rather avoid making a costly mistake by frying either of the rf modules, the stamp itself or the development board. Any help would be greatly appreciated.
Louis
Comments
Typically when something is pulled HIGH as is the case with the PDN pin you would simply set your I/O pin to LOW and then make it an OUTPUT. To release the PDN pin you simply make that pin an INPUT again. You can of course use HIGH and LOW but I thought I would share that with you anyway. Once the default state of the output latch is set it would be a matter of changing the I/O direction register to enable/disable the PDN pin.
As for RSSI since it’s an analog output signal you need to read it with something analog. As for driving an LED I would have to check the datasheet for the LINX chip to see if it will do that. Typically you would run it into an op-amp or transistor and drive your output device. I hope this helps. Take care.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
Louis