Baby-O (168) BAUD SETUP

I would like to setup the Baby-O to use the USART feature. If I use HyperTerm to talk to the USB Programmer, The Pololu programmer manual indicates that the HyperTerm BAUD rate must be set to 115,200. (Typing config shows that the link is working.) If I visit the Windows Device Manager, it shows that the Pololu USB Adapt. is set to 9600 BAUD, a little confusing! My question! If I use the Programmer for a USB adaptor, with the jumper moved from “P” to “U”, should the Baby-O USART registers UBRRnL & H be configured for 115200, or 9600?


The port settings you see in the Windows Device Manager are default settings for that port, but most programs (including Hyper Terminal) completely ignore these, and configure the port based on the program’s settings. So no matter what the Device Manager says, when you chat with the programmer with Hyper Terminal set to 115,200, that’s the baud rate the port is actually using.

Now, I don’t have a Pololu AVR programmer to verify this on, but I am a big fan of the Pololu USB-to-serial adapter, and I’m pretty sure that you only needed to use 115,200 baud to talk to the programmer because that’s the baud rate the on-board MCU is expecting. When you move the jumper over to the U side, you can get directly at the logic-level serial pins of the CP2102 USB-to-Serial adapter chip (bypassing the MCU). This means it doesn’t matter what baud rate you use (with in reason) so long as your terminal program and your Baby-O are set to the same one.

Also, I’m sure I don’t have to tell you this, but Hyper Terminal is a pretty cumbersome. There are some great free terminal programs out there, Br@y Terminal is my personal favorite. It’s a standalone executable with all the important functions up-front and super-intuitive.

So, what are your plans for the Baby-O?


P.S. You probably figured this out already, but the USART lines of the Baby-O aren’t connected to the ISP header. You’ll need to connect the programmer’s serial pins to the Baby-O separately.