K
Kaido Kert
Guest
Im looking for a solution of a simple homebrew incremental shaft encoder for
robot navigation.
I only have single sensor looking at encoder wheel, as i dont need
directional information ( i know which way the wheel is turning), so i only
need to count the impulses while moving, to get correct positioning info.
Tried to do that with Basic Stamp ( BS2 ), obviosly its just too slow for
simultaneously controlling servos AND monitoring encoders.
So i thought, im gonna just put a simpe counter to do the job, but then i'll
need loads of inputs on micro to read it. Well BS2 is able to read I2C
pretty good, so i started looking for a chip that could count and be read
over I2C.
The closest matches seem to be various Philips I2C clock/calendar chips like
PCF8583 and PCF8593.
The whole family is listed here:
http://www.philips.semiconductors.com/cgi-bin/catalog/catalog.pl/42460/42472
/index.html
Unfortunately i havent found any sample circuits/info on how to run it in
event-counting mode. Does anyone have any info, or could someone suggest
alternative solution ?
I really would like to have a dedicated chip for encoder. I already went
through trying to use old serial and PS2 mouse parts for encoder readings.
Serial mouse could be connected to BS2, through MAX232 or somesuch. But i
wasnt figure out how to turn it to "remote" mode, and thus it would need to
be polled constantly thus still being unable to control the servos properly.
PS/2 mice can be switched to "remote" or accumulated mode easily and they
can count up to 256 pulses before overflowing. But BS2 is just too slow to
talk over PS/2 bus directly. I could use the PAK-VIa PS/2 coprocessor (
http://www.al-williams.com/pak6.htm ), but its gonna take some time to order
it, and im not so sure its gonna work so well.
So, any ideas ?
-kert
robot navigation.
I only have single sensor looking at encoder wheel, as i dont need
directional information ( i know which way the wheel is turning), so i only
need to count the impulses while moving, to get correct positioning info.
Tried to do that with Basic Stamp ( BS2 ), obviosly its just too slow for
simultaneously controlling servos AND monitoring encoders.
So i thought, im gonna just put a simpe counter to do the job, but then i'll
need loads of inputs on micro to read it. Well BS2 is able to read I2C
pretty good, so i started looking for a chip that could count and be read
over I2C.
The closest matches seem to be various Philips I2C clock/calendar chips like
PCF8583 and PCF8593.
The whole family is listed here:
http://www.philips.semiconductors.com/cgi-bin/catalog/catalog.pl/42460/42472
/index.html
Unfortunately i havent found any sample circuits/info on how to run it in
event-counting mode. Does anyone have any info, or could someone suggest
alternative solution ?
I really would like to have a dedicated chip for encoder. I already went
through trying to use old serial and PS2 mouse parts for encoder readings.
Serial mouse could be connected to BS2, through MAX232 or somesuch. But i
wasnt figure out how to turn it to "remote" mode, and thus it would need to
be polled constantly thus still being unable to control the servos properly.
PS/2 mice can be switched to "remote" or accumulated mode easily and they
can count up to 256 pulses before overflowing. But BS2 is just too slow to
talk over PS/2 bus directly. I could use the PAK-VIa PS/2 coprocessor (
http://www.al-williams.com/pak6.htm ), but its gonna take some time to order
it, and im not so sure its gonna work so well.
So, any ideas ?
-kert