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Old thread has been locked -- no new posts accepted in this thread
???
06/25/09 12:02
Modified:
06/25/09 12:03
Read: times
#166451
- ambiguous?
Responding to: ???'s
previous message
Sivanand Somasundaram
said:
in MAx232 the polarity of the capacitor connected to pin 6 is ambiguos
You mean
C4
? How is it ambiguous?
It looks perfectly clear to me:
it is different in many sources.
The
datasheet
is the definitive document; if in doubt,
follow the
datasheet.
List of 137 messages in thread
Topic
Author
Date
debugging AT89S52
01/01/70 00:00
where?
01/01/70 00:00
FAQs
01/01/70 00:00
Image uploaded and other corrections made
01/01/70 00:00
You MUST use a max232 or equivalent
01/01/70 00:00
MAx232 connections
01/01/70 00:00
if you have connected the PC RS232 directly
01/01/70 00:00
ambiguous?
01/01/70 00:00
Not necessarily!
01/01/70 00:00
Image of MAx232 connection for reference
01/01/70 00:00
89S52 - PC -> MAX232 conenctions
01/01/70 00:00
max 232 connection
01/01/70 00:00
To test MAX232
01/01/70 00:00
Testing a Com port using hyperterminal
01/01/70 00:00
PC Loop-back
01/01/70 00:00
Connections of COm port
01/01/70 00:00
So what about direct on the COM port
01/01/70 00:00
Check the PC's driver
01/01/70 00:00
Testing an RS232 driver
01/01/70 00:00
results of rs232 testing
01/01/70 00:00
Hyperterminal
01/01/70 00:00
data not displayed in echo mode in hyperterminal
01/01/70 00:00
Why do you call it hypoterminal?
01/01/70 00:00
I got confused regarding the value of capacitors
01/01/70 00:00
MAx driver and hypertermianl problem solved but...
01/01/70 00:00
can somebosy please reply?
01/01/70 00:00
Try a step by step aproach
01/01/70 00:00
Reg Step by step approach
01/01/70 00:00
How are you programming the flash memory of AT89S52
01/01/70 00:00
clarifications
01/01/70 00:00
Not to UART
01/01/70 00:00
Additional info about the board AT89S52 and ISP
01/01/70 00:00
Many issues solved but one
01/01/70 00:00
How?
01/01/70 00:00
diode...connection
01/01/70 00:00
Explain with graph or text
01/01/70 00:00
clarification
01/01/70 00:00
Study the AT89S52 datasheets
01/01/70 00:00
Please read the answers you get
01/01/70 00:00
It works now!!!!
01/01/70 00:00
What series resistor?
01/01/70 00:00
Connection of diode
01/01/70 00:00
Please clarify
01/01/70 00:00
the problem is NOT the 2.7V
01/01/70 00:00
clarifications
01/01/70 00:00
Google Ohms law
01/01/70 00:00
Report
01/01/70 00:00
Measure pin voltage when held low, not hgh
01/01/70 00:00
trouble again
01/01/70 00:00
details...
01/01/70 00:00
Troll?
01/01/70 00:00
clarification
01/01/70 00:00
I am not an electrical engineer I am a mechanical engineer
01/01/70 00:00
Do not accept everything as is, Revise your schematic
01/01/70 00:00
who cares?
01/01/70 00:00
Short-circuit
01/01/70 00:00
OOPS, anyhow
01/01/70 00:00
circuit revised but ....
01/01/70 00:00
have changed to new buffers ..
01/01/70 00:00
Post the revised schematic to check
01/01/70 00:00
schematic
01/01/70 00:00
there are "LED resistors" whwre are the LEDs and
01/01/70 00:00
you are in deep waters
01/01/70 00:00
what's the error?
01/01/70 00:00
It is hopeless, but anyhow
01/01/70 00:00
Vf for diode
01/01/70 00:00
Too deep waters indeed, describe everything
01/01/70 00:00
then how do you propose they will both work when in patralle
01/01/70 00:00
Haven't you seen that he has series resistors with each LED?
01/01/70 00:00
update
01/01/70 00:00
Resistor value
01/01/70 00:00
update.-2
01/01/70 00:00
free-wheel diode
01/01/70 00:00
details of relay
01/01/70 00:00
details of relay-2
01/01/70 00:00
free-wheel diode always reversed
01/01/70 00:00
No simple diode but a zener in series!
01/01/70 00:00
zener and IN4148 already in series?
01/01/70 00:00
clarification
01/01/70 00:00
The datasheet is a bit confusing...
01/01/70 00:00
no space to connect
01/01/70 00:00
Solder it on the solder side!
01/01/70 00:00
Thanks..but
01/01/70 00:00
Did you made a PCB ?
01/01/70 00:00
YEs true
01/01/70 00:00
Regarding zener and In4148
01/01/70 00:00
update on relay testing
01/01/70 00:00
testing relay using multimeter
01/01/70 00:00
NO, NO, NO
01/01/70 00:00
as opposed to
01/01/70 00:00
what about the coil across the LEDs?
01/01/70 00:00
full picture of relay
01/01/70 00:00
use preview
01/01/70 00:00
true
01/01/70 00:00
Heaven, Erik, ...
01/01/70 00:00
it works but for relay orientation
01/01/70 00:00
Look at this, too
01/01/70 00:00
latest posts
01/01/70 00:00
Don't be so quick to experiment
01/01/70 00:00
clarifications
01/01/70 00:00
make simple tests like this
01/01/70 00:00
reg the test circuit..
01/01/70 00:00
circuit details
01/01/70 00:00
Still experimenting
01/01/70 00:00
Already covered in this thread - more than once
01/01/70 00:00
but how did the above circuit work?
01/01/70 00:00
Experiments can work, even if incorrect
01/01/70 00:00
there is no zener diode
01/01/70 00:00
Don't ignore the datasheet.
01/01/70 00:00
thanks
01/01/70 00:00
Forget the sales engineer!
01/01/70 00:00
Minimum turn-on voltage
01/01/70 00:00
it HAPPENS to
01/01/70 00:00
ther is no other way now
01/01/70 00:00
where there is a will, there is a way
01/01/70 00:00
is this what you are suggesting?
01/01/70 00:00
Relay
01/01/70 00:00
Finally reached the shore
01/01/70 00:00
Project completed ?
01/01/70 00:00
yes completed
01/01/70 00:00
Good luck!
01/01/70 00:00
Reagrding other relays
01/01/70 00:00
Scan through catalogs
01/01/70 00:00
you do not need to buy there, but
01/01/70 00:00
form factor
01/01/70 00:00
The datasheets normally have the answer
01/01/70 00:00
files
01/01/70 00:00
Not so many files
01/01/70 00:00
Regarding LEd
01/01/70 00:00
_always_ current-limited supply!
01/01/70 00:00
Only if it contains a current limiting resistor!
01/01/70 00:00
thanks and file updates
01/01/70 00:00
You can enormously save user space...
01/01/70 00:00
Hard now
01/01/70 00:00
Correct!
01/01/70 00:00
never do that
01/01/70 00:00
Kai, you must be able to see invisible ink
01/01/70 00:00
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