08-07-2021, 10:25 PM
(07-20-2021, 03:14 AM)biketool Wrote: I took a look at this IC, what do you all think about this as the receiver, since it has a TX function too it could be used to do many other things(especially if we bypass our POCSAG mode band-passes) including short range paging other Pinephones(or pagers), WSPR, or LoRa, maybe even FM audio tx for older cars(though the datasheet says FSK is the tx mode); perhaps a switchable power TX amp for greater range for licensed amateur radio ops on their freqs. If we can do that POCSAG will just be one function(will need another decoder than just the POCSAG hardware decoder IC, maybe an i2c sound card?) of a very useful pogo-pin add on without needing to go full HackRF.
https://www.ti.com/lit/ds/symlink/cc1000.pdf
I have not been able to move forward without this key IC but together I think we could start populating a breadboard once I hear some comments, my main concern is sensitivity though a LNA preamp might help while burning power.
Since this would require a controller anyways to keep power down I think my go-to attiny85 could bridge the i2c needs of both the RF transceiver and the decoder chips; also a very stable crystal so we can do more freq sensitive stuff than just wider band POCSAG signals.
Input from experienced RF engineers is key to choosing a good IC candidate as my experience with radio design is almost exclusively power hungry SDRs or discreet component QRP sets maybe with a DDS for HF that may not be as efficient, small, or sensitive as we will want for this project and all have had high part count.
Check this out: https://hackaday.com/2021/05/18/send-old...-hardware/
and https://www.soldierx.com/bbs/202105/Pock...ransmitter
Seems like using HopeRF RFM23BPW module. HopeRF is the company who teachs Pine64 on the Lora module design and tuning :-)
For the i2C to SPI protocol conversion TinyAVR design, just follow the PinePhone finger print back cover code and here is the link: https://github.com/zschroeder6212/tiny-i2c-spi
