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Hi,Originally Posted by mychangl
The MCP23016 will work with the 16f84a.Code:With three address lines you can set the address of up to eight devices. Binary / Decimal ============ 000 = 0 001 = 1 010 = 2 011 = 3 100 = 4 101 = 5 110 = 6 111 = 7
Use the software I2C commands of PicBasic Pro. (I2CIN and I2COUT).
* * *
See also this: (Basic Stamp + MCP23016).
http://www.parallax.com/dl/docs/cols.../col/nv109.pdf
Best regards,
Luciano
Last edited by Luciano; - 1st January 2008 at 15:43.
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Do you mean I2Read and I2Write ?
Sorry i am not familiar with it. However i would like to try.
Correct me if i am wrong.
From datasheet,
control 0h and 1h is to read or write to the ports
control 6h and 7h is to set port as input or output
Given scenario 1 :
Connect 23016 address as $01
Assign GP0.0 to GP0.7 as input (control address is 6h)
Assign GP1.0 to GP1.7 as output (control address is 7h)
the code will be :
addr var byte
addr=01
I2CWRITE DataPin,ClockPin,06,addr,[FF]
I2CWRITE DataPin,ClockPin,07,addr,[00]
Scenario 2 :
Read the data on GP0.0 to GP0.7 and put inside Sample1
the code will be :
I2CREAD DataPin,ClockPin,00,addr,[Sample1]
Scenario 3 :
Write data 44h on GP1.0 to GP1.7
the code will be :
I2CWRITE DataPin,ClockPin,00,addr,[44]
Cheers,
mychangl
"The Dream Is Everything"
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Hi,
Yes, with PicBasic Pro use I2CREAD and I2CWRITE.
(I2CIN and I2COUT are for the PicBasic compiler).
Best regards,
Luciano
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I took longer time to try out with MCP23016 because i am still using shift register to expand the I/O. Last week i decided to try out MCP23016. However it doesn't work, after few days trial & error and change the address, i almost give up. Not sure what happen. either the code or the IC faulty because i only have one piece.
Can someone advice ?
Appreciate that.
'MASTER CODE
'This test is to check output functionality ( LED ) - Running LED
'MCP23016 connected to address 0
INCLUDE "modedefs.bas"
'*****PORT Setup********************************************* *****************
GreenLED VAR PORTA.0'O Indicator Green
SDA VAR PORTA.1 'O Serial Data
SCL VAR PORTA.2 'O Serial Clock
RedLED VAR PORTA.3 'O Indicator Red
'*****Constant************************************ ****************************
CtrlRW1 CON 00 'Access to Set1 GP0
CtrlRW2 CON 01 'Access to Set2 GP1
CtrlDir1 CON 06 'Access to Set1 IODIR/0
CtrlDir2 CON 07 'Access to Set2 IODIR/1
'**VARIABLES************************************** ****************************
Address VAR BYTE 'Address size
Set1 VAR BYTE 'Place to put Data Set1
Set2 VAR BYTE 'Place to put Data Set2
Address=0 'Select MCP23016 address as 0
Set1=0 'Clear Set1
Set2=0 'Clear Set2
'*****INITIALIZING MCP23016 All as Output**************************************
I2CWrite SDA,SCL,CtrlDir1,Address,[00] 'Set as Output
Pause 10 'Delay 10ms
I2CWrite SDA,SCL,CtrlDir2,Address,[00] 'Set as Output
Pause 10 'Delay 10ms
Start :
Set1=$FF 'To turn on all LEDs connected to Set1
Set2=$FF 'TO turn ON all LEDs connected TO Set2
I2CWrite SDA,SCL,CtrlRW1,Address,[Set1] 'Turn on the LEDs
Pause 10 'Wait 10ms
I2CWrite SDA,SCL,CtrlRW2,Address,[Set2] 'Turn on the LEDs
Pause 10 'Wait 10ms
GoTo Start
Cheers,
mychangl
"The Dream Is Everything"
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You could have a label after the line where to jump if an error occurs with I2C, like this:
I2CWrite SDA,SCL,CtrlRW1,Address,[Set1], errorLabel
...
errorLabel:
LCDOUT "Error....
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The MCP23008 works reliably using I2C without any additional external components, but is quite intollerant of noise on the Supply Lines, and has a habit of 'locking-up' pulling down the supply rail when this happens.
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There is a newer version from microchip: MCP23017
It has an internal oscillator, no external C and R needed, also the pin layout is a bit nicer. I also had problems getting a MCP23016 to work reliably, finally it worked best without any timing C connected.
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Please clarify...
Thanks, i'll try MCP23017.
I know what going on wrong with the code...
3 things been observed :
1. I do not put "$" to determine the address in HEX
2. Before initializing MCP23016, it need to have short delay ( i use 50ms ) otherwise the whole program will not work.
3. The code should be I2CWrite SDA,SCL,Address,CtrlDir1,[00] not I2CWrite SDA,SCL,CtrlDir1,Address,[00]. This is confusing because the manual shows the address come after Control, but it does not work.
It works fine after the correction.
I need help to evaluate my second code.
I use GP1 as input and GP0 as output.
However this is what happened :
Input Triggered | Output Respond
----------------+-----------------
GP1.0 | No Respond
GP1.1 | GP0.0
GP1.2 | GP0.1
GP1.3 | GP0.2
GP1.4 | GP0.3
GP1.5 | GP0.4
GP1.6 | GP0.5
GP1.7 | GP0.6
GP0.7 never respond at all.
Anyone can help ?
Code:INCLUDE "modedefs.bas" '*****STARTUP***************************************************************** TRISA=%00000 TRISB=%00000000 '*****PORT Setup************************************************************** SDA VAR PORTA.1 'O Serial Data SCL VAR PORTA.2 'O Serial Clock '*****Constant**************************************************************** CtrlRW1 CON 00 'Set1 CtrlRW2 CON 01 'Set2 CtrlDir1 CON 06 'Set1 CtrlDir2 CON 07 'Set2 '**VARIABLES****************************************************************** Address VAR BYTE 'Address size Set VAR BYTE 'Temporary place to put Data Address=$40 'Set MCP23016 address as 01 Set=$00 'Clear Temporary Storage '*****INITIALIZING MCP23016 ************************************************** Pause 50 I2CWrite SDA,SCL,Address,CtrlDir1,[00] 'Set as Output Pause 10 'Delay 10ms I2CWrite SDA,SCL,Address,CtrlDir2,[$FF] 'Set as Input Pause 10 'Delay 10ms Start : I2CRead SDA,SCL,Address,CtrlRW2,[Set] 'Read from input, put in Set Pause 10 'Delay 10ms I2CWrite SDA,SCL,Address,CtrlRW1,[Set] 'Write data into Set Pause 10 'Delay 10ms GoTo Start
Cheers,
mychangl
"The Dream Is Everything"
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