i2c non-eeprom examples?

[RubenR]

Thanks for the reply. I've pulled up the ports and it look like it works now! It is possible to put the LED-driver into the test-mode and to set it back to normal operation.

The only problem is that I can't get a character on the display. To find te problem I've attached a serial cable to the PIC and added some debug commands.

The code I've used:


Include "modedefs.bas"
DEFINE OSC 20
'DEFINE I2C_HOLD 1

SCL VAR PORTB.4
SDA VAR PORTB.5

CommandByte VAR BYTE
SlaveAddress var BYTE
DataByte VAR BYTE
ReadData VAR BYTE
Character VAR BYTE

'Set Debug pin port
DEFINE DEBUG_REG PORTC
'Set Debug pin bit
DEFINE DEBUG_BIT 5
'Set Debug baud rate
DEFINE DEBUG_BAUD 2400
'Set Debug mode: 0 = true, 1 = inverted
DEFINE DEBUG_MODE 1


Init:

Debug "-->> Start <<--", 10 ,13

Debug "Test mode", 10 ,13
SlaveAddress = $A0 'Set the device address at the I2C-bus (datash. p. 10)
CommandByte = $07 'Set the Command Byte ($07 = displaytestmode. Datasheet page 11)
DataByte = $01 'Set the Data Byte
I2CWRITE SDA, SCL, SlaveAddress, CommandByte, [DataByte] 'Write the data to the I2C-device
I2CREAD SDA, SCL, SlaveAddress, [ReadData]
Debug "ReadData = ", dec ReadData ,10 ,13 ,10 ,13

pause 500

Debug "Normal mode", 10 ,13
SlaveAddress = $A0 'Set the device address at the I2C-bus (datash. p. 10)
CommandByte = $07 'Set the Command Byte ($07 = Normal mode. Datasheet page 11)
DataByte = $00 'Set the Data Byte
I2CWRITE SDA, SCL, SlaveAddress, CommandByte, [DataByte] 'Write the data to the I2C-device
I2CREAD SDA, SCL, SlaveAddress, [ReadData]
Debug "ReadData = ", dec ReadData ,10 ,13 ,10 ,13

pause 500

Debug "Set LED intensity 1", 10 ,13
SlaveAddress = $A0 'Set the device address at the I2C-bus (datash. p. 10)
CommandByte = $01 'Set the Command Byte ($01 = Intensity10. Datasheet page 11)
DataByte = $FF 'Intensity of all segments set to maximum (Page 20)
I2CWRITE SDA, SCL, SlaveAddress, CommandByte, [DataByte] 'Write the data to the I2C-device
I2CREAD SDA, SCL, SlaveAddress, [ReadData]
Debug "ReadData = ", dec ReadData ,10 ,13 ,10 ,13

pause 500

Debug "Set LED intensity 2", 10 ,13
SlaveAddress = $A0 'Set the device address at the I2C-bus (datash. p. 10)
CommandByte = $02 'Set the Command Byte ($02 = Intensity32. Datasheet page 11)
DataByte = $FF 'Intensity of all segments set to maximum (Page 20)
I2CWRITE SDA, SCL, SlaveAddress, CommandByte, [DataByte] 'Write the data to the I2C-device
I2CREAD SDA, SCL, SlaveAddress, [ReadData]
Debug "ReadData = ", dec ReadData ,10 ,13 ,10 ,13

pause 500

Debug "Set Scan-Limit", 10 ,13
SlaveAddress = $A0 'Set the device address at the I2C-bus (datash. p. 10)
CommandByte = $03 'Set the Command Byte ($01 = Intensity10. Datasheet page 11)
DataByte = $01 'Intensity of all segments set to maximum (Page 20)
I2CWRITE SDA, SCL, SlaveAddress, CommandByte, [DataByte] 'Write the data to the I2C-device
I2CREAD SDA, SCL, SlaveAddress, [ReadData]
Debug "ReadData = ", dec ReadData ,10 ,13 ,10 ,13

pause 500

Debug "Character 'I'D0,P0&P1", 10 ,13
SlaveAddress = $A0 'Set the device address at the I2C-bus (datash. p. 10)
CommandByte = $60 'Set the Command Byte ($60 = Digit 0 Plane P0 & P1. Datasheet page 11)
DataByte = $49 'Display Character 'I'
I2CWRITE SDA, SCL, SlaveAddress, CommandByte, [DataByte] 'Write the data to the I2C-device
I2CREAD SDA, SCL, SlaveAddress, [ReadData]
Debug "ReadData = ", dec ReadData ,10 ,13 ,10 ,13

Debug "-->> End <<--", 10 ,13 ,10 ,13 ,10 ,13

end


And this is the result at my serial port:


-->> Start <<--
Test mode
ReadData = 0

Normal mode
ReadData = 0

Set LED intensity 1
ReadData = 0

Set LED intensity 2
ReadData = 1

Set Scan-Limit
ReadData = 0

Character 'I'D0,P0&P1
ReadData = 0

-->> End <<--

While the chip is in test-mode, the LED's are all burning. After the testmode, no LED is burning.

[justDIY]

well, i had my basics confused ... hbusin/out is a proton command, not an melabs command - appologies


anyway the data sheet talks about "read-after-write verification" (pgs 7-9):

When performing read-after-write verification, reset the command byte's address because the stored byte address generally is autoincremented after the write (Table 4).

so I would try:

I2CWRITE SDA, SCL, SlaveAddress, CommandByte, [DataByte] ' write data to register
I2CREAD SDA, SCL, SlaveAddress, CommandByte, [ReadData] ' reset pointer and read register

depending how your program will end up, you can also use the auto-increment feature to write all the configuration with a single I2CWRITE command, just add more byte variables, after your DataByte

as far as no character showing up, not sure what to say there... from a cursory glance, I find no errors in what youve written compared to the datasheet. double, triple, quadruple check your wiring to the datahseet ... I experimented with maxim's 6956, a little simpler beast than what you have there, but it still took a lot of fiddling to make it work!

[RubenR]

Yes, it's working.
What I was doing wrong was not setting the intensity registers, so the LED's won't light up. Here's the configuration code I'm using now:


SetConfig:
SlaveAddressWrite = $A0
CommandByte = $04 'Set the Command Byte ($04 = Configuration Datasheet page 11)
DataByte = $81 '10000001 Tabel 7 page 12
FOR i = 0 to nAddress
I2CWRITE SDA, SCL, SlaveAddressWrite, CommandByte, [DataByte] 'Write the data to the I2C-device
I2CREAD SDA, SCL, SlaveAddressWrite, CommandByte, [RcvDataByte]
SlaveAddressWrite = SlaveAddressWrite + $02
NEXT i
return


LEDintensity: 'Set intensity of all LEDs
SlaveAddressWrite = $A0
CommandByte = $01 'Set the Command Byte ($01 = Intensity10. Datasheet page 11)
DataByte = Intensity '$FF 'Intensity of all segments set to maximum (Page 20)
I2CWRITE SDA, SCL, SlaveAddressWrite, CommandByte, [DataByte] 'Write the data to the I2C-device
I2CREAD SDA, SCL, SlaveAddressWrite, CommandByte, [RcvDataByte]
for i = 0 to nAddress
I2CWRITE SDA, SCL, SlaveAddressWrite, CommandByte, [DataByte] 'Write the data to the I2C-device
I2CREAD SDA, SCL, SlaveAddressWrite, CommandByte, [RcvDataByte]
SlaveAddressWrite = SlaveAddressWrite + $02
NEXT i

SlaveAddressWrite = $A0
CommandByte = $02 'Set the Command Byte ($01 = Intensity10. Datasheet page 11)
DataByte = Intensity '$FF 'Intensity of all segments set to maximum (Page 20)
I2CWRITE SDA, SCL, SlaveAddressWrite, CommandByte, [DataByte] 'Write the data to the I2C-device
I2CREAD SDA, SCL, SlaveAddressWrite, CommandByte, [RcvDataByte]
for i = 0 to nAddress
I2CWRITE SDA, SCL, SlaveAddressWrite, CommandByte, [DataByte] 'Write the data to the I2C-device
I2CREAD SDA, SCL, SlaveAddressWrite, CommandByte, [RcvDataByte]
SlaveAddressWrite = SlaveAddressWrite + $02
NEXT i
return

[luxornet]

Hi RubenR!

Can you post entire code you used to control MAX6953 driver?
I try to use what is posted here but I have many error.
Thank you very much