problem with ds1621 sx/b code
verobel
Posts: 81
Fellow sx/b coders;
I am trying to learn SX/B and have run some examples by others successfully but..
I wired up a 2 digit 7 seg. lcd on the PDBoard and initially got it to count from 0 to 99 in a loop.
Next I added 2 I2C chips DS1621 (no examples available) and 24LC64 (some examples available).
In the current program TempDI2.SXB I am trying to display the temperature but get -5· when I expect ~22
The new code (added to the previously working program) is shown below. The full program listing is attached.
Main:
· DO
····· tempC = GET_TEMP
····· tens = tempC / 10
····· ones = tempC // 10
· ...
' Subroutine Code
'
' GET_TEMP
' gets temp from DS1621 using I2C commands
' USE: temp = GET_TEMP
·GET_TEMP:
· I2CSTART SDA
· I2CSEND SDA, addrW························· ' prepare for convert command
· I2CSEND SDA, cmdConv··· ' request convert 1 temp. sample
· I2CSEND SDA, addrR··· ' prepare for readTemp command
· I2CRECV SDA, tempIn_MSB, Ack·· ' read the 2 bytes
· I2CRECV SDA, tempIn_LSB, Nak
· I2CSTOP SDA
· RETURN tempIn_MSB··· ' ignore 1/2 deg LSB for now
·Could some one confirm if the I2C sequence of commands is good.
·Could some one spot any obvious error in my SX/B code that would explain the wrong output -5 on the display?
·I believe the wiring is good: have Ra.0=SDA 1621.1,·Ra.1=SCL 1621.2 both with 4.7k pullup resistors.
A0=1 (5V), A1=0,A2=0
Thanks, John
I am trying to learn SX/B and have run some examples by others successfully but..
I wired up a 2 digit 7 seg. lcd on the PDBoard and initially got it to count from 0 to 99 in a loop.
Next I added 2 I2C chips DS1621 (no examples available) and 24LC64 (some examples available).
In the current program TempDI2.SXB I am trying to display the temperature but get -5· when I expect ~22
The new code (added to the previously working program) is shown below. The full program listing is attached.
Main:
· DO
····· tempC = GET_TEMP
····· tens = tempC / 10
····· ones = tempC // 10
· ...
' Subroutine Code
'
' GET_TEMP
' gets temp from DS1621 using I2C commands
' USE: temp = GET_TEMP
·GET_TEMP:
· I2CSTART SDA
· I2CSEND SDA, addrW························· ' prepare for convert command
· I2CSEND SDA, cmdConv··· ' request convert 1 temp. sample
· I2CSEND SDA, addrR··· ' prepare for readTemp command
· I2CRECV SDA, tempIn_MSB, Ack·· ' read the 2 bytes
· I2CRECV SDA, tempIn_LSB, Nak
· I2CSTOP SDA
· RETURN tempIn_MSB··· ' ignore 1/2 deg LSB for now
·Could some one confirm if the I2C sequence of commands is good.
·Could some one spot any obvious error in my SX/B code that would explain the wrong output -5 on the display?
·I believe the wiring is good: have Ra.0=SDA 1621.1,·Ra.1=SCL 1621.2 both with 4.7k pullup resistors.
A0=1 (5V), A1=0,A2=0
Thanks, John
SXB
5K
Comments
· I2CSTART SDA
· I2CSEND SDA, addrW························· ' prepare for convert command
· I2CSEND SDA, cmdConv··· ' request convert 1 temp. sample
· I2CSTOP SDA
· PAUSE 750 ' Allow time for conversion
· I2CSTART SDA
· I2CSend SDA, addrW
· I2CSend SDA, cmdReadT
· I2CSTART SDA
· I2CSEND SDA, addrR··· ' prepare for readTemp command
· I2CRECV SDA, tempIn_MSB, Ack·· ' read the 2 bytes
· I2CRECV SDA, tempIn_LSB, Nak
· I2CSTOP SDA
Bean.
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·
I had tried to step thru the assembler in Debug.. but that was of a barrier, even with the comments. So I was a bit relieved when the error was found in the higher level code.
I think I had some confusion on the data sheet about the need to repeati the Start command.
Thanks for your help, John
Since the SX/B compiler is my baby, I'm the only one that can "blame the compiler first" [noparse];)[/noparse]
Bean.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
My goal is to live forever...Or die trying.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
www.hittconsulting.com
·