Compass module and I2C bus

[mister_e]

Nice!

Now forward the info to Devantech

[vladimir059@hot]

DONE. I mailed Info to Devantech.
Best Wishes.
Vlad

[shaiqbashir]

Hi guys!

Well ! i have some confusions in understanding the following program :

1) what is the purpose and function of this line :

DEBUG " Compass Bearing ", # bearing,13,10

2) Why is the address be written as %11000000?

3) WHat is the function of this line:

i2cread dpin,cpin,%11000000,2,[bearing.Highbyte,bearing.lowbyte]

4) and what this DEC sign means, i have checked the help section, it is no command. Then why it is written there :

lcdout $fe, 1,"BEARING ",DEC BEARING/10


lcdout $fe, $c0,"Bearing ", dec bearing1

Please help me as soon as possible!

and can anyone tell me whats the cost of this CMPS-03?

Can we operate it through I2C on PIC16F84A?

[vladimir059@hot]

Hello shaiqbashir!

I will try to give you answers.
1) what is the purpose and function of this line :
DEBUG " Compass Bearing ", # bearing,13,10

This is optional line, for development purposes only. It is sends “bearing” value serially to a terminal. In my program this command sends serial string to PORT_C, pin No1, baud rate 2400.

2) Why is the address be written as %11000000?

This is address designated by Devantech (Devantech is company producing the compass module)

3) WHat is the function of this line:

i2cread dpin,cpin,%11000000,2,[bearing.Highbyte,bearing.lowbyte]
Function of this line is reading "bearing" value through I2C bus, as WORD size variable.


4) and what this DEC sign means, i have checked the help section, it is no command. Then why it is written there :

lcdout $fe, 1,"BEARING ",DEC BEARING/10
lcdout $fe, $c0,"Bearing ", dec bearing1

DEC means decimal. This is not command, this is modifier, it is similar to # sign and gives ASCII representation of value sending to LCD.

and can anyone tell me whats the cost of this CMPS-03?

http://www.robotshop.ca/home/product...le-cmps03.html

Can we operate it through I2C on PIC16F84A?

Why not? In my application I use PIC 16F872 because 16F84A has limited amount of ports (pins).
Best regards Vlad

[shaiqbashir]

Many Many Thanks Mr. Vladimir

please tell me the following two points as well!

1) Which type of LCD screen have u used. Can i use an LCD screen with three terminals (+5V, GND, control) using Serout command? What lcd u have used?

2) On each PIC, it is usually written that which is the SDA pin and which is the SLA one. While when i was reading the diagram of PIC16F84A , it was not mentioned. According to you , i can use this I2C on PIC16F84A, is it possible that we can use any two pins for I2C operation? or are there always two fixed pins dedicated for it?

I shall be looking for ur precious reply!

Take carez!

Good Bye!

[vladimir059@hot]

Hello shaiqbashir!

I used Hitachi style parallel LCD. As I understood you have serial LCD, it can be connected to PICs without problem , but you need to define , port ,pin, baud rate, and other protocol parameters. You can use SEROUT, SEROUT2 and DEBUG commands. DEBUG command is a bit more complicated as it’s involve DEFINE statements. Please check up PIC Basic PRO manual.

As your second question, frankly speaking I’m not I2C bus expert; I just began to learn it two-three weeks ago. I cannot give you comprehensive answers. It is all I know, some microcontrollers has designated I2C pins, and I used such PIC. I really don’t know how will work PICs without designated pins.
Good luck in your experiments
Vlad

[Archangel]

Many Many Thanks Mr. Vladimir

please tell me the following two points as well!
<font color=red>
1) Which type of LCD screen have u used. Can i use an LCD screen with three terminals (+5V, GND, control) using Serout command? What lcd u have used?

2) On each PIC, it is usually written that which is the SDA pin and which is the SLA one. While when i was reading the diagram of PIC16F84A , it was not mentioned. According to you , i can use this I2C on PIC16F84A, is it possible that we can use any two pins for I2C operation? or are there always two fixed pins dedicated for it?</font color>


Good Bye!

Hi shaiqbashir,
PBP Manual shows a schematic on page 85 using a 16F84 as an example.
Your serial LCD should hook up to the pin he defined as DEBUG. you must make sure the baud rates agree.
JS