I started thinking about pin usage on the ATMEGA328p microcontroller chip that I was planning on using this morning, and came across a problem. As mentioned in my previous post, I need eight ADCs for my design – not a problem when using the Arduino NANO, but it turns out that the ATMEGA328p chip only has 6 ADCs! The NANO uses a surface mounted version with extra ADCs, but I am not able to work with surface mount soldering – super annoying!
This means I have a couple of options:
- Reduce the number of ADCs used – this is not really an option as it would fundamentally affect the functionality of my module.
- Use multiple chips with serial communication between them – this is certainly possible, but will add extra circuitry and code complexity. I could potentially use an ATTINY85 as the second chip saving some space.
- Use an Arduino NANO in my circuit – this will take up extra space on the circuit, and looks more DIY and less professional. It will make it easier to load the software onto my chips, as the NANO has a USB port rather than needing to use a separate circuit for programming. This would also allow the option for future software updates.
I did a quick google search to compare the sizes of the NANO and ATEMGA328p DIP, and it actually turns out that they are pretty similar in size, which surprised me! This may push my decision towards sticking with the NANO, but I will need to do some more head scratching and draw some pinout sketches…
