Controller Arduino, must be mega?

[Jeff Duce]

I'm wondering if the controller has to be an arduino mega.  Looking to minimize size and cost and wondering if you could use a much smaller form factor like a nano?  It seems that there's only a handful of DIO pins used and you don't need the huge number of IOs on a mega.  Was mega used based on performance?

[jcve...@gmail.com]

The Mega has the same processor speed as the Nano the difference is that the Mega has MUCH more memory for programs, many more I/O pins and more serial ports.

The decision to use a Nano comes down to your system design The Nano has D1-D13 but 1 and 2 are the serial port. You need 3 lines for the LPF and one for PTT that leave 8 pins for other possible functions:

Display

Push Buttons

Serial coms with the radio

Fan control

If you use a I2C display it uses A4 and A5 so that frees up some lines. On the analog side you need to monitor FWD and RFL power, VDD, IDD and temp, maybe the transceiver if it's a FT817 or Xeigu.

If you can get the pin count down you might consider an ESP32 which adds WiFi and BT which would be useful for interfacing a IC705 and the ESP32 is much faster than the Nano and Mega which is good for graphical displays.

73,

Jim WA2EUJ 

[Randal Warren]

The inputs and outputs sure add up fast. We had to use the mega. See attached.

[Randal Warren]

On Monday, February 5, 2024 at 9:59:53 AM UTC-8 jcve...@gmail.com wrote: