Mike (@mik3ca)
I already am implementing that, but that counteracts another thing I'm trying to achieve in my project which is speed.With COBS, an extra byte (called escape character)...
I have an idea where I can transmit data on the packet to avoid byte stuffing. The way I would do it is to limit the possible byte combinations to one of 253 (instead...
I'm using an AT89S52, and I can also use AT89LP52 and AT89S8253.The primary reason is price. Also I know much of the assembly in the 8051 and I get more control...
I'm trying to figure out the best way to access continuous data from different parts of memory.
Here's a sample of my 8051 code:
;Set DPTR to 5678h
;and other...
I have extracted the following line from an intel HEX file in which some 8051 simulators believe have an incorrect checksum while an online tool believes it has...
But I'm not trying to send and receive data through the air. Every time the radio module turns on and the micro communicates it with the baud rate it expects to...
That's probably true, but I don't want a manual solution. I'm looking for one where I can control power using software
The thing with this particular circuit is that I won't keep it powered forever. I'm only going to use it every time I need to program a radio module to the proper...
question is, would my timeframe be in the milliseconds range?I mean if I'm testing the radio modules at different speeds, the magic string will come at different...
Yes you're understanding my logic.The local store does sell a few mosfets...
https://secure.sayal.com/STORE/ActionIndexC.asp?CL...
But I'm not sure which one to...
I own an HM-TRP radio module which I want automatically configured using just a microcontroller (at89C2051) and an external 5VDC power supply (USB). In the past...
Now that I think about it, I should have mentioned that I have hardwired the RW pin to ground, so checking the busy flag wont work. Plus I have no free GPIO pins...
I'm looking for good ways to integrate LCD processing code into software on an old 8051 IC.Because the human eye can't process stuff as fast as computers can, what...
I'm looking for a simple way to handle key presses as well as store an option to allow a repeating key or just a one time press and release. Through experimentation,...
Reply to all....I don't know how to reply to everyone at once but I'll put it down here.I tried plexiglass from a local arts and crafts store and that did not work.Yes,...
I have tried other forums but was not successful. Because my project is embedded related, I'll explain a bit. I'm making a lazertag game and I have realized that...
This is what I notice..I pit 560K and 10K in parallel (because 560K was already mounted on board to the connector) but I didn't swap the photodiode and resistor....
Ok, it turned out that what made things work at a good speed (after making the series resistor to 100 ohms) is to change the resistor feeding the phototransistor...
OK,I got the datasheet here and specs on page 5...
http://www.ti.com/lit/ds/symlink/sn74hc151.pdf
But for Voh condition, the test currents are negative values.Based...
the LED and 100 ohm were there just for testing purposes only. Since the multiplexer is 74HC based IC, if I'm not mistaken the output current maximum it can provide...
I remembered making a post here and on another forum about connecting outputs of sensors to the 8051 RXD pin via schmitt triggers and combined through a multiplexer.Here's...
I created a 4-channel sensor circuit with the following type of schematic because I want to keep my option of using the serial port of the 8051 to my advantage if...
For the life of me, I can't figure out why I can't program the AT89LP4052.I have programmed the AT89S52 and AT89LP52 before serially with my own hardware board.Now...
I currently made a board in which a 4-sensor unit is multiplexed into one output connected to P3.0 of an AT89C4051 microcontroller. The sensor is selected via P3.4...
So far I have made software for the same hardware that can detect whether an AT89S52 or an AT89LP52 is inserted into it because the introductory bytes required to...
I own multiple AT89C4051's, its a basic 8051 with flash rom and 128 bytes of ram of which most is used by other resources.
I have just enough free to store 40 bytes...
I can't find this in any datasheet, but I was thinking one reason why my packets transfer slowly (even on wired network) serially is because the individual bits...
I'm trying to NOT make the PC as my final server because if my PC ever gets a virus while my system is running then the system shuts down because of a virus.Sadly...
oops, I forgot to mention that my number board has a timer that turns on when new data is sensed. When timeout happens, all shift register's (74hc595) load clocks...
Ok, so I did your trick and expanded things to 24-bits. I tried worst case scenario for my situation of the number 999,999 and my simulator indicated it takes 1,260...
the static test was without the micro. The working version was with the slow micro (at89S52) but the non-working version was with the faster micro (at89LP52) yet...
I'm trying to figure out the fastest way to convert a 16-bit number to 4 digits for an LCD display. I did adopt the use of the fast 16-bit division on another thread...
hmm then I guess I'll need a different command. I'm already putting other things on a timer in the same system such as updating the LCD with information. I can't...
I have no scope, but maybe my problem is the batteries, but eventually I want my system to be able to run on batteries. Maybe I just need stronger batteries.
The signals are from GPIO pins, and yes I did make proper programming, otherwise it wouldn't work on the AT89S52. Both AT89S52 and AT89LP52 understand the same instruction...
When I first built the number unit, I tested it in a static fashion (by manually setting and clearing the clock line as well as the data line). It works wonderful...
Oh. Maybe that's my problem. I was running the board on batteries and I don't think the batteries are decent enough now. Now let's just say I wanted to run the thing...
Currently I own a few AT89S52's and AT89LP52's and I run them with 22.1184Mhz crystals.The difference between the two is that the AT89LP52 processes code 10x faster,...
I ran into an interesting situation as I'm developing my large system.As it stands now, the server continuously addresses each client with 11 bytes of data, mostly...
I have, but the problem is I'm doing wireless transfer through UART with an HM-TRP radio module and it only supports the 8-N-1 data format
Ok, I managed to get the microcontrollers (AT89LP52 and AT89S52) to execute code, but now I need a way to optimize my data flow.
I have one controller setup as...
Thats crazy that you had to do all that. I'll still be experimenting with this chip at all levels in hopes I'll get something successful. Worst case, I'll get some...
OK, Now this confuses me a bit... I read:
...Note that in some cases, external capacitors C1 and C2
may NOT be required due to the on-chip capacitance of the
...
I stared at that datasheet for a few hours. Yes it offers "compatibility mode" but I want faster execution. Even trying to execute port manipulating instructions...
That's why I set port pin values and used a multimeter as a test. I mean the only other thing I could use is an LED.Sorry if some are confused, but the chips I'm...
Pin 31 through 39 in all my designs are connected to VCC through a 10K resistor bus. The AT89S52, recognizes this pin as logic high and therefore fetches all instructions...
...almost winning the lottery.
Ok. So I used the AT89S52 numerous times on my target board as well as in my programmer and things are successful. So now I choose...
It turns out that I am an owner of one counterfeit chip. This is because I tried another one from the same package and that one works well.
This week my local supplier ordered some AT89LP52's for me and I bought them today and they all arrived in a plastic anti-static package which makes me think they...
I just realized one second after your answer that its the most brilliant answer. Yes I know the world is for the latest and greatest. Well the nice news is I ordered...
But I already made my hardware for the AT89S52. I order from Futurlec. I actually explored Digikey and Mouser electronics and I have ordered parts in the past from...
Well, I'm already against the current seeing I have no gf and no career, so I figure I might as well create my own career with making special equipment that people...
I'm trying to figure out if I can somehow save some more clock cycles in these routines.
Basically I have a transmit and receive function here for the serial port....
Call me crazy but I'm doing my work in assembler.Ok so I am implementing a smallish ring buffer because I don't have alot of memory to work with. If in the future...
I'm adjusting my serial receive routine so the interrupt only loads one character at a time and I have a separate routine in my mainline that does further processing...
In the midst of trying super compressed interrupts...Ok, so I was beginning to modify my code to shorten time spent in interrupts and after calculating things, I...
I did order some AT89S8253's online which seems to have an X2 option (double speed) but I'll have to wait a while for them.In the meantime, could I get a speed boost...
I put your text in italics and my relevant replies follow.
Wow. Kudos for nutting this out in assembler and getting it to the
point of functional even with some...
The reset (code 0FEh) is sent as a synchronization to all slaves to reset their internal pointers to the data so that when the next character is sent by the master,...
Ok, I'm showing my entire serial routine. Only thing I didn't include was netdata and serialmem address and I didnt include setting up SCON and IE and IP registers....
You must have typed this as I was putting your suggestions in practice.
Sadly, these ideas made the reception slower.
Now my new packet format is as follows:
Byte...
CustomSarge:I use an idea similar to yours except that the timer acts as a timeout interrupt but the serial routine forces a timeout when the full packet is received...
Thanks for your ideas.After further research before arriving here again, I will try some ideas from the modbus protocol (http://modbus.org/specs.php) especially...
After analyzing my own code 500,000 times, I'm starting to learn my serial data format isn't perfect.
Currently, my packet is arranged as 11 bytes as follows:
Byte...
I primarily refer to the following source for the 8051 programming information:
http://8052mcu.com/
But it says nothing about the operation of the RB8 bit in serial...
Thats an idea but I gotta watch some of my loops because they execute pretty fast (like under 20uS for pure idleness) and that won't be enough of a delay for an...
I'm trying to figure out the worst timing I could possibly use to update an 16 character by 4 row LCD display.Currently I have a timer that executes (as an interrupt)...
My computer has the parallel port and I even written software to send data through the parallel port to the programmer. I have access to a local shop that sells...
I made an AT89S52 programmer as shown below to be used with the PC parallel port.The nice part is that the thing works, however each time I want to initiate a new...
Ok, I should just leave my serial hardware as-is.One thing I have at my client end is another micro attached (AT89C4051). Basically its a high-speed sensor that...
UPDATE
I ran more tests. This time instead of using radio modules, I used a direct link (still with the 74HCT04 buffers in circuit). The link consisted of ardruino...
Note: All quoted text are from other members. My responses follow.
Do I take it your radio module is part of the PCB that also holds the
microcontroller?
Almost....
Sadly the HMTRP radio module documentation doesn't offer much detail. Yes its a nice idea to do a loopback but in a microcontroller world, I'll have to write another...
I'm trying to create a system in which one unit acts as a central server to 25 special hardware clients.
All devices utilize the same specs that I will explain...
Ok, the multiplication I figured out and I'm doing it as follows:
Lets call X the input 24-bit value,
and Y the multiplier, and Z the answer.
if the LSB is set...
The part of my project I need this for is a bank system in a game. What needs to happen is that at any given time, one decides to borrow any amount of cash up to...
>> I wrote this to calc the 16 bit number percentage of a 16 bit. It's a
framing hammer on a finishing nail, but it works. Good Hunting...
<<<)))code?...
>> 1. what are the 24-bit numbers for?
24-bit is the maximum bit capacity. Meaning the numbers I want to store would be as large as 1,000,000, so therefore...
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