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All other info about my probe is now in PicBasicPro FORUM in:
Probe to read quadrature encoder with DT_INT need help
After my success I will post all here on FORUM.
If any help and good idea pls write.
Many thanks to all good peoples here!
Best regards Robert
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I recommend you take a look at the 18F2431 series PIC. It has a motion feedback module built in that can be set up to keep track of an incremental encoder. It also has a lot of other goodies specifically targeted at motor control applications.
/Henrik.
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I was buy today 18F4431 and will move to it.Originally Posted by HenrikOlsson
At moment I looking for examples for it.
Thanks and regards Robert
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Hi,
This is cut and pasted from a larger program I have and this digested version is not tested so take it for what it is please. It's written for the 18F2431 so double check the pin assignments for the QEI module.
Again, no guarantees but I hope it serves as a starting point for you.Code:DEFINE HSER_RCSTA 90h 'USART receive status init. DEFINE HSER_TXSTA 24h 'USART transmit status init. DEFINE HSER_BAUD 57600 'Baudrate is 57600. ANSEL0 = 0 'All inputs as digital PortA = 0 PortB = 0 PortC = 0 TRISA = %11000 'QEI pins as inputs. TRISB = %00000000 TRISC = %10000000 'USART RX pin as input. QEICON = %00010100 'Setup QEI, 4X mode, reset on index. PosLow VAR BYTE 'Storage for the low byte of encoder count PosHigh VAR BYTE 'Storage for the high byte of encoder count PosTemp VAR BYTE 'Temporary storage for low byte of encder count Position VAR WORD 'Actual encoder position, 16bit word. CLEAR Main: Gosub GetPosition HSEROUT ["QEI Count: " , #Position, 10] Pause 100 Goto Main GetPosition: 'Since the position counter isn't double buffered we can get to situations 'where the lowbyte overflows between readings of the high and the low byte. This 'is prevented by reading the low byte two times and compare the two readings. 'If they are the same then we're fine, if not re-read the registers. PosHigh = POSCNTH 'Get high byte of counter PosLow = POSCNTL 'Get low byte of counter PosTemp = POSCNTL 'Get low byte again If PosLow - PosTemp = 0 then Goto Done 'Compare, if equal we're done. PosHigh = POSCNTH 'If not, get values again. PosLow = POSCNTL Done: Position = POSHIGH * 256 + PosLow 'Put high and lowbyte together. RETURN END
/Henrik.
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Hi Henrik,
I started playing with the 4431 DIP version and wonder if you have ran into this with the one you are using. Maybe it is a 4331 problem, maybe whole series.
When using a 4Mhz resonator and have the config set for HSPLL and DEFINE OSC 16 all works well.
If I replace the 4Mhz with a 10 Mhz and try DEFINE OSC 40 everything goes erratic.
The PIC runs but even a simple "blinky" will blink randomly.
Here is the very simple code and configs I was playing with to set the OSC.
Code:@ __CONFIG _CONFIG1H, _OSC_HSPLL_1H @ __CONFIG _CONFIG2H, _WDTEN_ON_2H & _WDPS_512_2H @ __CONFIG _CONFIG2L, _BOREN_OFF_2L & _PWRTEN_ON_2L @ __CONFIG _CONFIG3H, _MCLRE_OFF_3H @ __CONFIG _CONFIG4L, _LVP_OFF_4L DEFINE OSC 16 START:HIGH PORTD.1:PAUSE 500 LOW PORTD.1:PAUSE 500:GOTO START
Dave
Always wear safety glasses while programming.
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My first step to make led blink and probe with these code:
And led wor blink...Code:define osc 20 ADCON1 = 7 led1 var porta.0 led2 var porta.1 high led1 low led2 pause 1000 loop: toggle led1 pause 500 toggle led2 pause 500 goto loop
Now we will learn other fuses and options on 18F4431..
But I still mean we must be WIZARD to get all we need..
There is 400 pages of datasheet.
All what I want to make is UHU type of PMDC control to interface it to MACH3 software for CNC.
Idea come from original UHU controller from Uli Hubert from Germany.
He use ATTINY2313 and make full stf WOW.
Can you image these :
He put in that little chip quadrature encoder full measure of his speed , direction and velocity reading ,
capture coming pulse from PC wich is from 1-5 uS, PID control , RS232 terminal , 20KHz PWM , current measure , and motor control ...ETC.
Then with 18F4431 must be much easy to do that.
His UHU controller is maybe the best in world and I was test it like finished module on my friend CNC wich work 2 years without error 10h/day .
Regards Robert
Last edited by phoenix_1; - 31st August 2009 at 23:03.
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Hi mackrackit and Henrik,
My PIC is 18F4431
I have success with 20MHz XTAL and define osc 20 , fuse HS.
I found motor with encoder with INDEX pin and little modific Hanrik code.
Result is 16 bit counter but I must find calculation becouse my encoder is 500 pulse per full rev of motor shaft.
Henrik you was give me good way for start with 18F4431..thanks man again.
Last edited by phoenix_1; - 1st September 2009 at 08:55.
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Mine works fine with 20Mhz HS also. It is when I try to run at 40Mhz HSPLL the problem starts. Maybe I have some bad 10s that are running a bit fast???
I have some new 10Mhz on order, find out then.
Dave
Always wear safety glasses while programming.
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Maybe you need to set manuel 4 nibbles of config manuel :
and probe ?Code:bit 7 IESO: Internal External Switchover bit 1 = Internal External Switchover mode enabled 0 = Internal External Switchover mode disabled bit 6 FCMEN: Fail-Safe Clock Monitor Enable bit 1 = Fail-Safe Clock Monitor enabled 0 = Fail-Safe Clock Monitor disabled bit 5-4 Unimplemented: Read as ‘0’ bit 3-0 FOSC<3:0>: Oscillator Selection bits 11xx = External RC oscillator, CLKO function on RA6 1001 = Internal oscillator block, CLKO function on RA6 and port function on RA7 1000 = Internal oscillator block, port function on RA6 and port function on RA7 0111 = External RC oscillator, port function on RA6 0110 = HS oscillator, PLL enabled (clock frequency = 4 x FOSC1) 0101 = EC oscillator, port function on RA6 0100 = EC oscillator, CLKO function on RA6 0010 = HS oscillator 0001 = XT oscillator 0000 = LP oscillator
Last edited by phoenix_1; - 1st September 2009 at 20:34.
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Duh!!!!
In my haste I made the stupid mistake of NOT having capacitors near the PIC across VDD/VSS. A friend pointed this out.
The PIC runs fine at 40Mhz.
Dave
Always wear safety glasses while programming.
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You is the member of simple peoples TEAM... :-) like me.
Regards Robert
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What if my ENCODER have only A and B output's and dont have INDEX pin ?
Can I use it ???
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Dave,
I've never used the PLL on this series of PIC's I've run it on 4Mhz and 20Mhz "straight" though without problems, x-tals though, not resonators. Please keep as posted if/when you find the culprit.
Robert,
Yes the UHU-servo chip is impressive - I have a couple of them on 160V/25A drives (the HP-UHU) and they perform very well indeed. I've been meaning to play with replacing the UHU chip with a 18F2431 to gain some performance, mostly in the encoder count frequency. I've found the max encoder count frequency on the UHU-chip to be ~130kHz. Haven't got around to that yet though....
You can use the encoder without index, the difference would be that the count doesn't automatically reset each each rev of the motor - something you probably don't want it to do anyway. Read up on the operation of the QEI module and QEICON register - you can set it up to operate in a few different ways.
/Henrik.
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Hi Henrik,
Yes I will measure a couple of encoder today to find if there INDEX pin.
Maybe with some logic chip from CD40XX serie I can provide INDEX pulses if there isn't INDEX pin ?
Regards and thanks for replay to all.
Robert
Last edited by phoenix_1; - 1st September 2009 at 07:41.
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hard way to finish of idea of own uhu wuth friends from these forum
Here is success probe with count encoder from 0 to 2000 for one turn of shaft of motor.
Will continue...Code:' Pic 18F4431 @ 20MHz true XTAL define osc 20 DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive DEFINE HSER_TXSTA 24h ' Enable transmit, BRGH = 1 DEFINE HSER_SPBRG 64 ' 19200 Baud @ 20MHz, 0.16% DEFINE HSER_CLROERR 1 ' Clear overflow automatically ADCON0=0 'Turn of ADC ANSEL0=0 'Make Port A inputs Digital PortA = 0 PortB = 0 PortC = 0 TRISA = %011100 'QEI pins as inputs. TRISB = %00000000 TRISC = %10000000 'USART RX pin as input. QEICON=%11001100 DFLTCON = %00111000 ' enable error filter for all capture inputs MAXCNTL = %11001111 'lowbyte = 207 MAXCNTH = %00000111 'highbyte = 7 but after math: highbyte * 256 = 1792 + 207 = 1999 'QEICON = %00010100 'Setup QEI, 4X mode, reset on index. PosLow VAR BYTE 'Storage for the low byte of encoder count PosHigh VAR BYTE 'Storage for the high byte of encoder count PosTemp VAR BYTE 'Temporary storage for low byte of encder count Position VAR WORD 'Actual encoder position, 16bit word. POSCNTL = 0 ' clear lowbyte of counter for start POSCNTH = 0 ' clear highbyte of counter for start CLEAR Main: Gosub GetPosition HSEROUT [dec position] Pause 100 Goto Main GetPosition: 'Since the position counter isn't double buffered we can get to situations 'where the lowbyte overflows between readings of the high and the low byte. This 'is prevented by reading the low byte two times and compare the two readings. 'If they are the same then we're fine, if not re-read the registers. PosHigh = POSCNTH 'Get high byte of counter PosLow = POSCNTL 'Get low byte of counter PosTemp = POSCNTL 'Get low byte again If PosLow - PosTemp = 0 then Goto Done 'Compare, if equal we're done. PosHigh = POSCNTH 'If not, get values again. PosLow = POSCNTL Done: Position = POSHIGH * 256 + PosLow 'Put high and lowbyte together. RETURN END
Robert
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