HOODEY
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pic18f spi
I have a pic interfaced with a RTC and tdc1000 altrasound chip. The rtc requires spi mode mode (1) and the tdc require mode 3.
This is in a loop. However once i switch the spi back to mode 1 the rtc displays incorrect values. DS1305 is the real time clock.
Once the spi mode is not changed the rtc has no issue. I find this extremely strange.
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qhb
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Re: pic18f spi
2018/10/15 12:28:43
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Are you using a CS line with both devices, and switching mode while both CS signals are idle?
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NKurzman
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Re: pic18f spi
2018/10/15 12:39:23
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Are you disabling the MSSP before changing modes?
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HOODEY
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Re: pic18f spi
2018/10/15 20:25:11
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I am using two different chip select lines. I am not disabling MSSP before switching modes. Before calling the tdc1000 routines i switch to mode 3 without disabling mssp and it has no issues. At one point i diasbled mssp and call the spi init routine again with mode 1. Same result. When I comment out the mode change the tdc fails but the rtc is happymad: 
; PORTB,0 output SPI Chip Select tdc1000
; PORTE,0 ouput dS1305 chip enable
call Usart_Init
movf RCREG,W ; Clear Interrupt flag may have been set before
movf RCREG,W ; Clear Interrupt flag may have been set before
movf RCREG,W ; Clear Interrupt flag may have been set before
bcf PIR1, RCIF
call setDateAndTime
bsf INTCON, RBIE ;EnABLE PORT B INTERRUPTS
;Enable peripheral Interrupts so USART can received data from
bsf INTCON, GIE ;Enable global Interrupts
bsf INTCON, PEIE
emailsentloop:
call read_clock ; think this clears any interrupt flags as well as reading the time
; bsf SSPCON1,CKP
; bsf SSPSTAT,CKE
movlw d'10'
call Long_Delay
call inittdc1011
call performtdcmeasurement
bcf PORTB,3 ;Put TDC1011 to sleep
movlw d'40'
call Long_Delay
bsf PORTD,0 ; Enable esp8266 will not conflict with rtc as rtc already set earlier rtc use serial comms with terminal window
call setupESP8266
call sendemail
bcf PORTD,0 ;Put ESP8266 to sleep
; bcf OSCCON,IDLEN ;Enable sleep mode.
; sleep
; nop
; nop
goto emailsentloop
post edited by HOODEY - 2018/10/15 20:37:06
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qhb
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Re: pic18f spi
2018/10/15 20:40:25
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Are you using B3 and D0 as your CS lines?
The TDC1011 uses an active low CS, and I suspect the ESP8266 does too, but you are driving your pins the other way round (active high).
(And BCF PIR1,RCIF is pointless, that flag is read-only.)
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jack@kksound
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Re: pic18f spi
2018/10/16 07:35:44
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Also use LATx instead of PORTx for single bit outputs.
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HOODEY
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Re: pic18f spi
2018/10/16 16:49:45
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PORTB,3 is the enable button of the tdc1000. I bring it high when making a measurement then pull it low when done. PORTD,0 goes to the ch_pd pin. i hold it low until i am ready to send an email. PORTE,0 is the ds1305 enable pin..active high PORTB,0 is the tdc1000 chip select active low. STILL NO JOY emailsentloop:
call read_clock ; think this clears any interrupt flags as well as reading the time
bcf RTC_CE
bcf SSPCON1,SSPEN ; SSP Disable
nop
nop
nop
nop
bsf SSPCON1,CKP
bsf SSPSTAT,CKE
bsf SSPCON1,SSPEN ; SSP Enable
movlw d'10'
call Long_Delay
call inittdc1011
call performtdcmeasurement
bcf PORTB,3 ;Put TDC1011 to sleep
movlw d'40'
call Long_Delay
bsf PORTD,0 ; Enable esp8266 will not conflict with rtc as rtc already set earlier rtc use serial comms with terminal window
call setupESP8266
call sendemail
bcf PORTD,0 ;Put ESP8266 to sleep
; bcf OSCCON,IDLEN ;Enable sleep mode.
; sleep
; nop
; nop
bcf SSPCON1,SSPEN ; SSP Disable
nop
nop
nop
nop
bcf SSPCON1,CKP
bsf SSPSTAT,CKE
bsf SSPCON1,SSPEN ; SSP Enable
nop
post edited by HOODEY - 2018/10/16 16:51:37
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qhb
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Re: pic18f spi
2018/10/16 17:26:01
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I can't see your code controlling PORTB,0 anywhere.
It is very frustrating trying to diagnose code when you don't post the important bits.
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HOODEY
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Re: pic18f spi
2018/10/16 20:03:11
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FIinally got it working. Datasheet is very misleading. Datasheet says rtc should not be able to operate in mode 0 . I switch to mode 0 for rtc then to mode 3 for tdc then back to mode 0.
post edited by HOODEY - 2018/10/17 05:58:34
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Danno
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Re: pic18f spi
2018/10/24 16:17:40
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Which datasheet is misleading?
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HOODEY
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Re: pic18f spi
2018/10/30 10:27:29
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jack@kksound
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Re: pic18f spi
2018/10/30 10:37:15
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HOODEY
ds1305.
Maybe post the parts you feel are misleading, someone may be able to clarify?
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