Future MAX232 question

[AtomSoft]

Can i use a PIC16/18 to communicate with a MAX232 chip ? Like TTL (transistor-transistor logic) ? Im not planning nothing now just asking for future reference. I really dont want to scour the net looking for this info because im not looking for schematics and stuff i juts want to make sure its possible.

Basic info i need can be answered by anyone i guess:

1. Can PIC interface with MAX232
2. Can i only send 1s and 0s or can i send actual letters and numbers to max232?
3. Thank you

 

[dknguyen]

1. Yes. The MAX is made to convert 5V (maybe even 3.3V though I am sure there are other versions out there that do) to RS232 (+/-12V signals). Does a 5V PIC output 5V signals? Yup!

2. You always (with a PIC or anything else) send 0s and 1s- combinations of which represent textual letters and numbers or pure numbers if you use binary counting systems. It doesn't matter. It's always 0s and 1s. What matters is how you interpret them.

3. Does not compute. Not a question.

 

[AtomSoft]

lol thanks!

 

[atferrari]

Max 232

Strictly speaking you don't communicate with the MAX232.You use it to communicate your PIC with, most probably, a PC.

MAX232 is an IC containing two pairs of RS-232 drivers / receivers.

It is in charge of converting your 1s and 0s in the appropriate levels as required by the (RS232) standard (or close to).

To any practical purpose, the IC is "transparent" to the communication of your PIC with whatever you link it.

 

[AtomSoft]

Hold on aren't you communicating with the MAX232 because you are indeed sending it information. which in turn it send the information to your PC. Like this

PIC ----> Max232 ----> PC
then
PC ----> MAX232 ----> PIC

I call that communicating with it because you have to send it info. which in turns send out your info converted to the appropriate levels.

I think of it as a interpreter like i dont know Spanish but i know a guy who knows english/spanish so i tell him to tell some other spanish person something (btw i do know spanish tho lol)

 

[donniedj]

MAX232 is no form of communication. MAX232 is just a level shifter. It converts +12v and -12v to -5v and +5v and that is all. A basic inverter and amplifier build into a single IC. MAX232 is not a passive device but in terms of communication it is passive just like the very wire connecting the PIC to the PC. It just a conductor of electrical current.

You do not need to send data to a MAX232. You can use transistors to perform the level shifting and accomplish the same communication. In fact the PIC only needs to Up-Convert its +5v levels to -12v and +12v when sending data out. The PIC can actually receive raw RS232 data with the aid of a diode and zener clamp. 2 PIC's can communicate with one another without need for the MAX232. MAX232 is primarily for legacy devices. Modern devices equipped with UARTs cannot even use a MAX232 for it will damage the device.

Notice no MAX232 in these diagrams:
1. PIC ---->RS232<----PIC
2. PIC ---->RS232<----USB to micro bridge (FT232RL)

 

[AtomSoft]

Ask yourself this... Does the data go through the MAX232? Even if its not telling it what to do its going through it and that is all i meant by communicating. I dont mean that you write to it and it writes back i mean you send a to it it sends a out to pc and pc sends b to it and it send b to pic. Kinda like the post office.

Sorry for the confusion. Also how can i send data back and forth to PC/PIC without USB meaning Serial (DB9)

 

[dknguyen]

Ask yourself this... Does the data go through the MAX232? Even if its not telling it what to do its going through it and that is all i meant by communicating. I dont mean that you write to it and it writes back i mean you send a to it it sends a out to pc and pc sends b to it and it send b to pic. Kinda like the post office.

Sorry for the confusion. Also how can i send data back and forth to PC/PIC without USB meaning Serial (DB9)

With the MAX232. THat's what it's made for. Just stick on a DB9 connector.,

 

[AtomSoft]

Ok thats all i need to know (for now lol)

Thanks to all

 

[blueroomelectronics]

Your Junebug (and the PICkit2) have a serial TTL to USB terminal emulator.

 

[AtomSoft]

Cool! Even i know im too much of a nooB to try and understand USB programming and stuff. I dont even want to get into it as of yet untill i get a firm grasp of the basics.

I should hopefully have my junebug by tommorow if not friday. In about 1 month if all goes well im going to buy a Mongoose and a Dragonfly . I like to keep things seperate lol So learning is more simple. (its my own way of grasping things)

 

[dknguyen]

Cool! Even i know im too much of a nooB to try and understand USB programming and stuff. I dont even want to get into it as of yet untill i get a firm grasp of the basics.

It's actually ridiculously difficult to work with "real" USB (ie. not making something that appears as a UART/RS-232 that uses the USB line but actually making something USB-USB). It's not noob.

 

[AtomSoft]

Cool that actually makes me feel better because when i get lost later on with it i know its not only me lol

 

[Pommie]

There are many hairless souls due to the frustration of USB descriptors.

Mike.

 

[dknguyen]

Yeah, the company I was working with over the summer decided to use RS-232 virtual COM ports that use a physical USB rather than use native USB.

 

[AtomSoft]

LOL mike.

Wow so i guess i ill take my time getting into it(ill bother you guys some time in the future for help lol or if i learn i can help lol)

 

[donniedj]

Data goes through wire. Wire is not a communication device. Both are conduits keeping current from traveling in any random direction. Best get a grab on what MAX232.

 

[AtomSoft]

LOL your funny wire isnt a communication device? Lol read more then. So your telling me you can communicate to another pic without any wires? Traces? You must be god. Wire is like a highway and and the data is the car you cant drive without a road so you cant communicate without wires/trace so i would call that a communication device

 

[DSGarcia]

Should one consider serial buffers for serial communications, particularly for higher BAUD rates? What is recommended?

 

[dknguyen]

Buffers are usually built into the devices already. This includes microcontrollers and SPI-RS232 ICs. But yeah if you don't have any (I don't know why you wouldn't though) then you really should have them.