09-05-2020, 06:21 PM
(09-03-2020, 04:47 AM)biketool Wrote: For example a S-7040D can do all of the decoding internally and output serial, it is a very cheap 1cm IC and just needs a receiver chip a serial line, clock, and power, the 'ROM' line could be from the phone or a real ROM on the module.
http://www.sih.com.hk/sih_eng/products/i...040d_e.pdf
All that is really required is a RF rx circuit, for testing possibly a FM radio IC and antenna.
There are several amateur radio projects to do POCSAG paging under US and European amateur radio rules, a SDR with a 50ohm load could also be used in close proximity or over a cable with an inline atteunator to the receiver to send legally low unlicensed signals sufficient to activate the pager circuit.
Put the receiver on a flexible kapton PCB with the radio IC and connect the serial lines and we can get to writing the silent mode callback/answer software.
(as an aside using RTL-SDR for always on paging rx, or most other mobile power budget applications is not a useful direction as that chip is notoriously power hungry)
You can design a small piggyback board using a microcontroller to control pager chip and communicate with PinePhone thru pogo pin i2c communication. The modem can be hardware disable thru dip switch or you can have write a program disable the modem and acrtivate when plan to use. For sure the program need to factor in the model initialization sequence and works with phone manager driver.
