Question about 18F4450

[mackrackit]

A row of blocks on the LCD might be the contrast needs adjusted. Pin #3 on the LCD.

More info would help.

[Darrel Taylor]

The 18F4550 has analog functions on PORT's A, B and E.

ADCON1=%00000111

Doesn't turn them all off.
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[manwolf]

Darrel

Provided the right clue, I had overlooked one PORT. Reread the datasheet and discovered the error of my ways.

ADCON1 = %00001111 did the trick.

Thank you kind sir.

[manwolf]

Also overlooked the fact that I ordered the wrong PIC. I wanted a 18F4550 but ordered 18F4450 and then couldn't figure out why no I2C. 4550 has and 4450 does not.

If someone needs a couple of 18F4450 let me know.

[Darrel Taylor]

Don't give them away yet.

Did you know that the PBP I2C commands don't use the Hardware MSSP module?

You can still use I2CREAD and I2CWRITE.
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[manwolf]

Darrel
No I didn't know that, I have been using the MSSP pins and figured that was the way it had to be.
The code I have written works on the 877A and 887 but not on the 4450. I am reading and writting to EEPROM.

I am currently using this to set the ports. (LAB-X1 board)

DataPin var PORTC.4
ClkPin var PORTC.3

I inserted the 4450 and programmed it, everything worked except the writting to EEPROM.

Guess I should have looked a little more closely at the datasheets. Pins changed in 4450, so no I2C on LAB-X1 Board.

877a - Pin18 - SCL - c3
Pin23 - SDA - c4

4450 - Pin18 - Vusb - Input
Pin23 - c4

Waiting for a few remaining parts to be able to start using Breadboard, then I can get off of the hardwired ports on the LAB-X1.

Thanks for your timely help there Darrel.

[Darrel Taylor]

> ... be able to start using Breadboard, then I can get off of the hardwired ports on the LAB-X1.

Ahhhh, freedom at last.

And, while I've never owned a LAB-X1 ... I think it's possible to cut the trace in-between the header rows, to isolate the pin from the peripherals. Then the peripherals can be wired to any other pin as needed.

I've seen it done before to allow using a 16F84 on the Lab-X1. (ICSP pins are different)

For RC3 its P2 pins 15-16, RC4 is P3 pins 15-16.

HTH,

[ErnieM]

Also overlooked the fact that I ordered the wrong PIC. I wanted a 18F4550 but ordered 18F4450 and then couldn't figure out why no I2C. 4550 has and 4450 does not.

If someone needs a couple of 18F4450 let me know.

Funny you say that, I just completed a project where I made the same mistake in ordering the breadboard parts: got 4450 and thought I had 4550's.

Lead to some funny bugs because I was using a different compiler and there the target mattered (due to the differing ammount of RAM).

Also, both devices host the same MSSP Module, so hardware I2C is the same on both. (I'm sure of this because I wrote code to use it on the 4450 that recompiled & ran flawlessly once I got the correct 4550's.)

[manwolf]

Funny you say that, I just completed a project where I made the same mistake in ordering the breadboard parts: got 4450 and thought I had 4550's.

Lead to some funny bugs because I was using a different compiler and there the target mattered (due to the differing ammount of RAM).

Also, both devices host the same MSSP Module, so hardware I2C is the same on both. (I'm sure of this because I wrote code to use it on the 4450 that recompiled & ran flawlessly once I got the correct 4550's.)

ErnieM
My problem is that the LAB X1 is hard wired as to which pins are I2C, as Darrel pointed out the PBP commands work on any port.
But MicroChip says no MSSP on 4450.(from their site.)
0 -UART
1 -A/E/USART
0 -SPI
0 -I2C
0 -MSSP(SPI/I2C)

I am going to give the 4450 a shot and see what happens, I can always switch if it doesn't work out.

Thanks for the info, good to know in the future.

[ErnieM]

But MicroChip says no MSSP on 4450.(from their site.)

But they say yes to MSSP on page 1 of the data sheet.