Re: Programming Arduino proc in Hilltopper-20


The Hilltopper 20’s J5 connects to the MPU’s Tx, Rx, and reset pins. You can connect to J5 from an UNO board’s DIO 0, 1, ground and reset or alternatively using a USB-FTDI cable, but you do need the reset pin to program.  J6 is the i2c bus, which is not used for programming.


I recommend stashing the original ‘factory programmed’ MPU safely away in a drawer, and using a copy for experimenting.


73, -Lloyd (WA4EFS)


From: [] On Behalf Of Ted via
Sent: Tuesday, February 08, 2022 8:36 AM
Subject: [4SQRP] Programming Arduino proc in Hilltopper-20


Hi, all.

While I try to whittle away at the loud "pop" each time I send a CW character and get more RX audio out of the volume knob, I'm also reading up on a mod for different tuning steps & even an LCD screen (for learning purposes only, really).  How does one actually connect to the processor to download/upload sketches to it? 

Does one connect to one of the un-pinned ports in the radio such as J6 or does the proc have to come out and sit on a burner type board?   I know just enough about Arduino programming to really make a mess but we have to start somewhere. 

Tnx in advance,


Join to automatically receive all group messages.