I used my voltmeter to measure the voltage across the +V and GND on the UART of the Robostix and no voltage registered. Does the UART get power from the laptop USB or from the Robostix power supply? Or do you supply a separate power to the FT232R breakout board? I measured the voltage across the breakout board and there also no voltage. Is it possible my UART cable has bad wiring?


On Sat, Mar 15, 2008 at 10:58 AM, Melanie <melanie.vida@gmail.com> wrote:

I was able to download the bootloader to my robostix and verify it from the flash. I had to go to Board and set and read the clock frequency at 125 kHz to get this part of the problem fixed.
After changing the clock frequency to 125 kHz I was able to program and verify the flash contents has the bootloader.

Now my problem is that I am no longer using the AVRISP cable. I have moved to the UART cable which has a FT232R Breakout board to my USB port. AVR Studio can't connect any longer to the Robostix.

My settings are to connect via STK500 or AVRISP and auto detect the COM port.

No response from the board. I wonder how I can download a program via UART to Robostix now that I have the bootloader there.

Please advise?

Thank you,


Message: 7
Date: Sun, 9 Mar 2008 22:07:35 -0800
From: "Dave Hylands" <dhylands@gmail.com>
Subject: Re: [Gumstix-users] Flashing Orange LED
To: "General mailing list for gumstix users."
Content-Type: text/plain; charset=ISO-8859-1

Hi Melanie,

On Sun, Mar 9, 2008 at 11:20 AM, Melanie <melanie.vida@gmail.com> wrote:
> In the Makefile for the bootloader-stk500 I found these parameters set:
> MK_OS               = avr
> MK_AVR_PROGRAMMER  ?= stk500
> MK_stk500_PORT        = COM1
> ifeq ($(TARGET),)
> # No TARGET specified, so use some default
> MK_AVR_MCU          = m16
> MK_AVR_FREQ         = 4MHz
> all:
> I'm using the USB port and the avrisp from digikey
> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=ATAVRISP2-ND
> So it seems the makefile is all wrong, for my programmer?
> Also this is set for ATMega16 and I'm using ATmega128. Will need to know
> what to change from the programmer so I can set this up correctly?

I use this partiicular bootloader on a wide variety of ATMega
processors, so I designed it to be used with variables passed in on
the make command line.

If I invoke it like

make TARGET=Stinger

Then it will use these variables:

Stinger_MCU             = m8
Stinger_FREQ            = 16MHz
Stinger_LED             = B 3
Stinger_SW              =

This will in turn cause the MK_AVR_MCU, MK_AVR_FREQ, MK_OBJ_DIR and
MK_BIN_DIR variable to be set for a particular target. Stinger is one
of my minisumo robots, and it has the LEDs connected up a particular

To configure the bootloader.

If you invoke it like


Then it will use:

MK_AVR_MCU          = m16
MK_AVR_FREQ         = 4MHz

You can override any of these on the command line, like so:

make MK_AVR_MCU=m128 MK_AVR_FREQ=16MHz

will configure it for an ATMega128 running at 16 MHz, which is what
the robostix uses.

I just updated the Makefile to add a target for the robostix, so you can now do:

make TARGET=robostix

to build a robostix version of the bootloader.

Dave Hylands
Vancouver, BC, Canada


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