Need for Bootloader?

[Superman]

I've looked through the $50 robot tutorial, and am thinking about giving it a try.

I'm trying to understand exactly what the need is for a bootloader.
Based on the $50 tutorial, I can get a programmer that uploads via a serial port on a PC (USB to Serial adapter available), or I can get a more expensive programmer that appears to connect via USB on a PC.

From what I can tell, I can add a UART to the robot, that allows me to connect directly from the UART to the serial port on a PC.  My question, is why would I go to this extra trouble.  Is it faster?  More reliable?

What am I missing?

Superman

[pomprocker]

in my honest opinion...


bootloaders are ok..could be better

right now i'm just sticking to the programmer.

if i were you id get the more expensive avrisp mk II and solder the 2x3 header onto your board instead of the 2x5 header for the serial programmer.

reason is that unless you have a true serial port on your computer, the usb to serial only emulates and will take like 2 hours to program your robot instead of the 30 seconds it should take with either a direct serial port, or the more expensive programmer.

[Superman]

I was planning on going with the more expensive programmer.

So is the bootloader really only useful if you are using the usb to serial adapter, and want to avoid the 2 hour loading?

[pomprocker]

the bootloader is useful for people who buy MCU boards and don't have a programmer. they can just use a usb cable to program their robots.

[Admin]

Here is another reason, picture these scenarios:

A physics class decides to build the $50 robot, 10 of them actually. So do you buy 10 programmers (expensive?), share just one or two (causing many delays?), or upload the bootloader and never need a programmer again?

Or suppose you know someone with a programmer, but he won't let you keep it. You'd then use the bootloader to save yourself some money on the programmer.

I put a bootloader on the Axon to save everyone the ~$40 or so cost of a bootloader