MCU jungle

One of the many important choices when starting a hardware project is to choose the part that is going to be what everything else revolves around. Namely the Microcontroller.

I knew my minimum requirements were something like this:

• 1 SPI
• 2 I²S with master clock out
• 1 I²C
• 1 U(S)ART
• LCD 8080/6800 parallel peripheral
• MMC/SDIO
• USB FS (pref HS) Device

These all need to be accessible at the same time, so I don’t want to keep reconfiguring pins and all that jazz. I want a chip powerful enough to comfortably do what I want it to do. Comfortably for me, that is.

Gathering all the information

Initially I considered various models from Atmel, NXP, Texas Instruments, Renesas, ST Microelectronics. They were my first choice as I had experience with their environments – albeit just slightly for some of them – and would have at least a bit know-how to kick start the project. Though after having a frustrated but kind chat with the kind folks over at EEVBlog the excellent youtuber mikeselectricstuff tipped off about a contender! Just like that Microchip and their PIC32MZ got thrown into the mix.

As in any project I start every decision with being as open minded as possible. Gathering information and the last part has taken me too long to be good at: ASKING FOR ADVICE AND HELP!

There’s never anything wrong with asking kindly for input from your peers.

Narrowing it back down

Let’s take a step back on evaluate what’s important when selecting a micro for a project that you want out of the door. Not a project for learning. I love an opportunity to learn, but this project is not it. I’m hyped and want to get started! So, let’s review:

1. Peripheral support for the intended selection of external input and output
2. Sensible package (for me this means no BGA)
3. More than enough space to fit the current scope of the program, plus additional features of the future
4. Time to market
   1. Any previous experience with the chip or it’s close relatives?
   2. Is the part released and available in high quantities?
   3. Is the part already used in designs you can play with, a devkit perhaps?

Make a decision and stick with it as long it’s practical

With that in mind I came to realize that I should go for the 32bit family I’ve got the most experience in and that is the STM32F1. It’s what we’ve used over at Wice AS:

Wice SmartSensor

This particular board is hand soldered. And my first experience with surface mount components. Never going back!

So, why go through this exercise if I knew all along that I had previous experience with a chip that could probably do what I needed from it?

Maybe there existed a microcontroller designed especially for streaming four channels of audio off an SD card! Though, I have more tasks planned for this thing so even that would not change my mind.

Immediately.

I’ll be using the smallest STM32F103Z I can get away with!

Later!