nobcha23のエアバンド受信機自作ブログ DIY airband receiver BLOG

エアバンドレシーバーキットの組み立て、改造を手掛けます Assemble and remodel Chinese airband receiver kit

I have ported CesarSound's VFO sketch on R909 receiver. R909受信機にVFOスケッチを移しました

I designed a local oscillator PCB with Si5351a controled by Arduino. This panel portion PCB is containing Arduino, Si5351a module, and switches.

(CPUはArduino po miniかATMega428Pが選択でき、表示は1602Aかi2c接続のLCD、発振器部はSi5351aモジュールを使う。その試作について先に報告しました。)


使ったスケッチは、CesarSoundさんがPROJECT HUBに公開されている"10kHz to 225MHz VFO/RF Generator with Si5351 - Version 2"をもとに改造を加えたもので、RF信号源を作りました。そして今回は、そのスケッチをR909に移植し、受信機を動かします。

R909 remodeled

I got CesarSound's VFO sketch on PROJECT HUB and edited it as a RF signal generator. This time furtherly I remodeled for R909 radio. In R909 sketch there is u8g2 library but the display design was 1602 format. I'm thanking CesarSound for providing nice material.




そのかわり、設定周波数を20波とり、局名呼称を簡易表示しました。ワタシは伊丹空港のそばに住んでいるので、118.1MHzはITW(Itami ToWerとしました)KAPはKIXのアプローチとか。

As a result the flash memory size is 87%, and SRAM is 35%(about 700bytes). OLED function is asking about more than 1000bytes on running. I could not incorpolated EEPROM channel memory functions. Insteadly I determined 20 waves for my local station usage. ie: 118.1MHz=ITW(Itami ToWer), 132.4MHz=TSK(Tokyo control SHikoku sector).



Operation rule.
Naturally the function status is "0" and the rotary encoder gives increment or decrement by step frequency value.
The crick by push button of the rotary encoder brings step frequncy change.
To push the function key 1 kicks the function status of "2" and "3". When "2", the rotary encoder gives increment or decrement for the volume level. When "3", the rotary encoder gives increment or decrement for the squelch level. 
To push the function key 1 calls the pre determined frequency one by one.

R909 newer display



I would like to use Si4735/32 chip for the mother radio. On that case the capacity of PU2CLR of about 4k bytes are far more ATMega428P size.