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Servo Tester 2

Hardware

Software

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Software

New: Version 1.00 of the software is released on 21/5 2004. The beta test is over, and the source has been released.

The software is written in AVR assembler. Both a compiled version and the source are available from the download page.

When the AVR is programmed, I recommend the following fuse settings (remember, with an AVR, 0 means programmed/enabled, and 1 means unprogrammed):

OCDEN

1

On chip debugger (controlled by JTAG)

JTAGEN

0

Enable JTAG interface

SPIEN

0

Enable SPI programming

EESAVE

0

Preserve EEPROM while flashing new firmware

BOOTSZ[1..0]

11

Boot loader size (not used)

BOOTRST

1

Disable boot loader

BODLEVEL

0

Brown-out detection level 4.0V

BODEN

0

Enable brown-out detector

CKOPT

0

External high frequency crystal (slow startup)

CKSEL[3..0]

1111

External high frequency crystal (slow startup)

SUT[1..0]

11

External high frequency crystal (slow startup)



Still missing in the software

The serial interface software hasn't been written yet.



The rest of this page hasn't been written yet. The following is the content of the old beta development page:

New in beta 0.07:
A signal from a phototransistor can be connected to PB0. More hardware is needed for this feature to work. This will be added to the schematic as soon as I have made some tests.
Update: Schematic updated, but I haven't quite finished the tacho circuit yet. I'll experiment a bit more when I receive the prototype PCB's.

New in beta 0.08:
An external voltage can be applied to PA0 (with appropriate scaling and protection that is), and the servo tester can show the voltage of the battery/supply or whatever. Similarly a (scaled) voltage can be applied to PA1, and it will show up as a measured current.
For this to work, be sure to apply an external reference voltage to AREF. The value isn't that important, as long as it is between 2.5V and Vcc. The voltage and current displayed in the servo tester can be calibrated in the setup-menu. My final design will use a precision voltage reference at 4.096V.
Update: The newest schematic has the correct voltage reference circuit. But I have redesigned the current-measurement circuit a bit, so the software will display some quite wrong currents. This will be corrected in beta 0.10.

New in beta 0.09:
Minor bugfixes, and a new bar-mode. Try to press and hold the button when editing a pulsewidth.

New in alpha 0.10:
Removed internal pullup on rotary encoder pins.
Added support for backlight.
Added a couple of configuration options.

New in beta 0.11:
Fixed some bugs in the setup menu.
Added a bit more detailed information in the Input Stat menu.

New in alpha 0.12:
Fixed current readout to allow for negative currents.
Alpha 0.12 isn't tested in any way yet. I don't have the hardware to do it right now. The PCB hasn't been mounted yet and my STK500 development kit is currently in use for another, unrelated, project.

New in beta 0.13:
Added setup option for unipolar or bipolar current measurement circuits.
Added calibration for current zero-point.
Fixed some minor cosmetic issues, due to a change from one LCD to another type, both supposed to be fully HD44780 compatible. Funny how I keep finding minor differences from display to display.

New in beta 0.15:
Added a reset setup to default option.
Added low battery warning.

New in beta 0.16:
Fixed a few menu texts.

New in beta 0.17:
Minor internal changes.

New in beta 0.18:
Total rewrite of bar mode display.

New in version 1.00:
Nothing but the version number.



Bug reports, suggestions and comments are welcome: Contact me here

ejberg.dk

Servo Tester 2

Hardware

Software

Downloads