Jump to content


  • Content Count

  • Joined

  • Last visited

Posts posted by mityeltu

  1. So, my win7 machine finally gave up the ghost. Interestingly, my win xp system is still working like a champ. Can't connect it to the network, but it still works great.

    Anyway, I'll be 'upgrading' to a new laptop with windows 10. Can anyone tell me if sourceboose ide and compilers are compatible with windows 10, or am I going to have issues? If it won't run right, then I guess I'll buy windows 7 and use that as long as possible. I really don't want to have to go with microchip's ide and compilers - they are soooo cumbersome.

  2. I am making new .h and .tdf files for the 16f1788 chip that I wan to use for a new project. Why I wan to use this chip as opposed to another that might already have these files built is not important for this discussion.

    I have run through the .h file and am at the last section, but I don't understand where I can find the eeprom base address that is used in any of the existing .h files. For instance, the file for the 16f1783 that I am using as a template calls out the address as 0xf000. I can't find this information anywhere in the datasheet for this chip. Where can I find it? Is it always the same? If not, how can I verify the location for the chip I am currently working on?

    Can anyone tell me what section it's in?

  3. I am using the PWM, but a 50% duty cycle is what needs to be there due to the discharge of the capacitor after it charges. If I lengthen the DC, then the cap may not discharge enough for the next charge cycle and the timing will be messed up.

    I also found out that the comparator interrupts on any change in the output. I dodn't know that up front, so I can use the discharge interrupt to setup for the next charge cycle.

    I realize that I'm using tmr2 for the pwm, but there does not seem to be a good way of using that to catch the beginning of the pwm cycle. I have fed the pwm output into INT0 and this seems to work, but I suspect there is a better way. i don't understand how to use tmr2 to catch the pwm leading edge, but either way it will wind up being an interrupt, so whether a tmr2 or INT0 I guess doesn't really matter.

    What do you think?

  4. I am attempting to make an ohmmeter out of this chip by pulsing a pin using PWM. The pin has a resistor capacitor series network. The resistor is the unit under test. I can use tmr3 to get the time to reach a specific voltage level (1T = 0.63 x VDD) and can interrupt when the comparator trips, but how do I catch the start of the pulse? Is there an interrupt for pulse start or am I goign to need to feed the PWM signal into an external int? Or maybe one of you smart guys has a better way.

    Any thoughts?

  5. I am attempting to use the rand and srand functions to generate a "random" pause between sections of my code. I am using the 18F2510, have added the rand.pic18.lib file to my project and have included the rand.h file in the program.

    I keep getting negative numbers in my random number variable. I don't understand this as the routine states that an unsigned short should be returned from the call. I wrote the following as a test of the rand and srand functions to see what is happening.

    char buff[9];
    char* ptr;
    unsigned short random_int;
    for(i = 0; i < 10; i++)
    	random_int = rand();
    	ptr = itoa(random_int,buff,10);	//	contained in stdlib.h

    The values I get form this are as follows:

    15322, -16984, -9592, -22399, -30702, -32477, 4657, 8984, 12677, 6234

    Can someone please explain to me what I am doing wrong?

    I just modified the code to give me hex numbers instead of decimals (radix 16 instead of 10). The results are 3bda, bda8, da88, a881, 8812, 8123, 1231, 2318, 3185, 185a. None of these are negative from the standpoint of an unsigned short. Why am I getting signed numbers in this?

    What is the lprintf (or itoa) doing that it should not? What have I missed? Can someone please explain this to me?

  6. What? "as a float 0x41bba752 = 0x4e83774f"?! Wait.... I'm going to go do some research on this.... I obviously missed something in C training. I'll have to get back to you on this. That makes absolutely no sens at all to me. In fact, at the moment, that seems like a complete contradiction.


    Not saying you're wrong. In fact, I'm saying you're probably right and I just don't understand. So, thank you for the correction, and I'm gonna go and relearn - or maybe just learn - what it is you;re talking about.



  7. I'm not sure how that is really any different. If I take a floating point variable and shift in 0x41bba752 and take a second floating point variable and load it with 23.4567, do they not contain the same hex values? That is really confusing if they would not be the same. I understand what you mean about the integer type value being very large, but if the bits in a float variable loaded with 23.4567 are in the same order as the one loaded with 0x41bba752, why do they produce different values?


    Is it becuase of what you said above? "a float is a pointer... " So, somehow when a float is declared, the compiler knows to grab 4 bytes, but uses each byte differently than if the float is loaded with the same bit pattern in a different way? Why does that make any sense?


    Wait, is it backwards? If I shift in the bits in reverse byte order, wil I get the correct value in the float?

  8. I'll try both today.


    Can anyone explain why my code doesn't work? I realize that an int is only 2 bytes, but the fact is a float is 4 bytes and if I load a float with the value 23.4567, the hex value stored in the variable should be 0x41bba752 based in IEEE. So, if I shift those bits into the variable, why do I get such strange results? As I said, if I load the variable with 23.4567 and then use the method listed above, the LCD will have 23.4567 on it, but when I shift the bits into the variable and perform the above function, the LCD gives me nonsense. Is there a reason for this that I am not understanding?

  9. int i, f;
    float fnum = 0x41bba752; // this should be 23.4567
    i = float32_to int32(fnum);
    f = float32_to_int32(float32_mul(float32_sub(fnum,float32_from_int32(i)),10000));

    I am attempting to recombine a set of 4 bytes sent via I2c into a floating point number. I can see the 4 bytes being transferred using a logic analyzer and they are correct for the number I am transferring, but I can't get the recombined number to diaply correctly, so I tried to just load the floating point number as a hex value and I get garbage on the LCD.


    Here's what I'm doing: see above (I guess - this thing never puts my code where I want it).


    Anyway, the LCD shows -23040.-1 which is obviously wrong. So, why am I gettign such garbage? Any ideas?

    If I use fnum = 23.4567, the LCD shows 23.4567. Maybe I did the conversion wrong, but Im pretty sure that 23.4567 = 0x41bba752.


  10. I am trying to encapsulate 2 ports from 18F2620 into a single variable. What I want to be able to do is something like the following pseudocode


    variable ex_port = porta:portb // 16 bits of 2 ports in a single variable

    for (z = 0, z<16, z++)

    ex_port.z = 1

    next z


    what I'm trying to do is to sequence through both ports as well as to be able to address each individual port pin wihtout having to first address the individual port. I hope that makes sense.


    Is there some way to bundle the ports together like this?


    Since boostc does not support bitfields, this becomes pretty large if I used a structure of bytes.

    I hope I'm not just making this way harder than it needs to be. Is there an easy way?

  11. I have been trying for the last couple of days to program the 18f24j11. I know there are some problems with the header file included in boostc, but I think I have fixed them. Section of header file is attached.


    However, fixing the header file doesn't fix the chip. I still have no life. Program is primitive, but I am just trying to get anything to work. I am using pickit2 to program the chip. No errors when programming.


    Is there anything you guys see that is wrong with the code/header? Is there some wierd way to program the chip that is different from other 18f chips? I am using 3.3v power supply, so I know that is not the issue.


    Any thoughts on this?



  12. //SLAVE CODE
    sspcon.CKP = 0;
    sspbuf = 22;
    sspcon1.WCOL = 0;
    sspbuf = 0x22;
    sspcon.CKP = 1;
    i2c_write(i2c_slave_add | 0x01);	//	write to slave
    i2c_write(0x04);	//	write command "Read_Temp"
    //wait till sspbuf is full, then read out the data
    UART_SendString("  Temp: ");
    t_dat = sspbuf;
    itoa(sspbuf,buff,10);	//	prepare for uart
    UART_Write_Text(buff);	//	send data to uart

    I have managed to get a master slave system working (mostly) with a pair of 16F1519 chips. I am certain the I2C is working as I am able to make an LED on the slave turn on/off and blink on command from the master.


    I am now trying to have the slave send data back to the master, but I'm not getting anything back. I have tried several arrangements on both the master and slave to get data back, biut nothing yet. Does anyone have a working snippet I can see on how the master sends to get the data and the slave responds to send the data?


    My code is below for anyone who wants to try their luck at deciphering my madness. Still not sure why the code always gets stuck at the top of this.



  13. Is there an easy way to set the configuration bits in the Sourceboost IDE? It might seem lazy, and maybe I've been spoiled by using MPLAB and Oshonsoft compilers as they have a nice module for setting the bits and generating the necessary code to include in the firmware. Is there anything like that in the Sourceboost IDE? I've looked but couldn't find anything. If not, is there an easy way to go about it?


    I've been using the meLABS meCongfi software to get the code close, but it still needs some tweeking after pasting and I'd like to just set it and forget. I know that once I have them set I can just copy/paste into new programs, but it really seems like there should be an easy way to get them set the first time.


    For anyone who is interested, I'm also working on a VB project to do this for a number of the chips that I use frequently. If anyone wants a copy, I'll post it here. And if there is a chip you want included, let me know and I'll try to code it in.

  14. I have a working version (albeit very simple) of I2C that is targetted to 16f1519. I am attempting to port this over to 18f2510. I have verified that all the addresses in the i2c_driver.h match what is available on the 18f2510 (in other words, they are thye same as on the 16f1519). I have not changed anything in the header file. I have made sure that the config registers are correct for the new target.


    Problem, when I comile the program for the new target I keep getting the same error "failed to parse template arguments".


    As I understand this, it is telling me that somehow the arguments I am passing the templates are not correct for the target I have specified. That would indicate that the addresses are not correct, right? But they are. I ahve quadruple checked that. I have also verified that the mapped addresses are not outside the memory banks of the pic. I don't understand what to do from here. This should be an easy process, but I just don't know what to do. Can someone help me, please?

  15. After searching for a long time to find some decent working examples (that I could understand and follow), I managed to cobble together a very basic, simple working example of I2C master and slave. In additon, the master communicates via UART through MAX232 to the PC serial port. This is NOT elegent, but it does work.


    The hardware is a pair of 16F1519 with internal 8MHz oscillator, resistor on the SDA and SCL (I2C) buses are 4.7k to VCC (+5V), LED is on both master and slave at PORTD.1 (pin 14), MAX232 chip is interfaced per the attached drawing using info from the datasheet. Tha's all there is... well, and the serial cable which follows the attached drawing. (NOTE: if the picture of the connections is too small, I found it here: http://microcontrollerprojects00.blogspot.com/2012/03/pic-serial-communication-tutorial-uart.html


    The terminal program I am using is Realterm - make sure you change the port to 9600 baud and set the port to whatever your serial port is (Port 1 on my laptop) and click "Change"


    I hope this helps others.


    Happy coding,





  • Create New...