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  1. Sadlercomfort

    12VDC Fan - 4 Pin

    Just to update incase anyone else plans on doing something similar: The 4-pin PWM 12VDC fan can be controlled using the PWM output of a microcontroller, which varies the PWM signal voltage from 0-5V by setting the duty cycle. Here's the circuit I used: However, the PWM frequency should be...
  2. Sadlercomfort

    12VDC Fan - 4 Pin

    Right, after further investigation I believe its 5v. I'm currently using this module from ebay to control my fans: https://www.ebay.co.uk/itm/12V-PWM-PC-CPU-Fan-Temperature-Control-Speed-Controller-Module-High-Temp-Alarm/302554878308?epid=835782064&hash=item4671ad1164:g:ZN0AAOSwA4dWHvI4 But...
  3. Sadlercomfort

    12VDC Fan - 4 Pin

    The 300mA current will come directly from the +12V and Gnd pin right. I thought there might be an internal Mosfet inside the fan, switching the ground based on the PWM signal at the gate, which would be rated for 300mA.
  4. Sadlercomfort

    12VDC Fan - 4 Pin

    Simple question.. Is it okay to assume I can connect the PWM pin of my fan directly to the 5V PWM output of my microcontroller? Maybe with a 100Ω resistor and a 5V Z diode? https://www.arctic.ac/uk_en/downloads/dl/file/id/2233/f14_pwm_spec_sheet_english.pdf
  5. Sadlercomfort

    Choosing the right NTC

    How.. Because it's too hot and I can feel it with my hand. Plus based on the speed of the fan. I wouldn't call this an assumption, but an educated guess. However, I've just taken some measurements to give you an idea. The NTC measures around 53k at 23 degrees C my current room temperature and...
  6. Sadlercomfort

    Choosing the right NTC

    Hi Guys, I have a 12VDC fan hooked up to a Pwm module, which is controlled using an NTC. Shown in this link: https://www.ebay.co.uk/p/12v-PWM-PC-CPU-Fan-Temperature-Control-Speed-Controller-Module-High-temp-Alarm/835782064?iid=302358014128 After adjusting the trim pots the Dc fan stays off...
  7. Sadlercomfort

    PCB building

    Very nice! =)
  8. Sadlercomfort

    sleep mode for PIC

    I think the simplest solution is to disable all the config bits and there functions.. Since the watchdog timer, timer1 etc will consume power. If you post your circuit diagram we may be able to simplify it to consume less power. Also, this document is very useful...
  9. Sadlercomfort

    sleep mode for PIC

    Is your question how to put the microcontroller into sleep mode? Or specifically how to setup the config bits and I/O lines to reduce power consumption?
  10. Sadlercomfort

    Need help storing keypad input - Hi-Tech C

    I seem to have fixed the reset problem, I checked everything from the master clear circuit to the decoupling capacitors but everything was fine. I'm guessing it was something to do with my interrupt routines, causing a reset. I decided not to use my keypad, It's just to difficult to display...
  11. Sadlercomfort

    Need help storing keypad input - Hi-Tech C

    Thanks, Hi-tech C has a "eeprom_routines.h" file which can be used quite easily, similar to what you have shown. I haven't attempted the eeprom yet. I'm now having even more issues with my microcontroller, which goes into unexpected reset.
  12. Sadlercomfort

    Need help storing keypad input - Hi-Tech C

    Okay, thanks. What does the microchip website have? Don't think I've ever used there resources.
  13. Sadlercomfort

    Need help storing keypad input - Hi-Tech C

    lol, yeah i know microchip.. been a long day
  14. Sadlercomfort

    Need help storing keypad input - Hi-Tech C

    I'm not sure which website your talking about..
  15. Sadlercomfort

    Need help storing keypad input - Hi-Tech C

    Hi Adam, PIC16F877A The above code is in a header file where the Keypad_scan() function is called from the main program. I would like the above program to combine each pressed key, into one value, then maybe return it. I will probably store this in the eeprom. The person can write up too 20...
  16. Sadlercomfort

    Need help storing keypad input - Hi-Tech C

    Hi Guys, I'm trying to write a program which will record the pressed keys on the keypad, after the person hits enter from an external standard push button. As the user presses buttons, the numbers get written on an LCD display one by one. This works nicely, but I now need to record all the...
  17. Sadlercomfort

    Multiple interrupt functions but one interrupt vector

    Never-mind, I've fixed it :cool: I have't used the busy pin to check if the LCD is ready to write data too, just delays. I had to make the delays abit longer.
  18. Sadlercomfort

    Multiple interrupt functions but one interrupt vector

    Hope you don't mind me reawakening this post.. My LCD is displaying random characters. I upgraded my resonator to 16MHz and change the programs oscillator configuration bit to HS. Nothing has changed in the software, apart from changing the ocillator to 16MHz and the config bit. My program...
  19. Sadlercomfort

    Multiple interrupt functions but one interrupt vector

    I will be following this very closely! It's the first time I've heard about it, but at least I've learnt something. I don't think it will be an issue, but I am using a 4MHz resonator, but if i need to I will upgrade this.
  20. Sadlercomfort

    Multiple interrupt functions but one interrupt vector

    I believe the amount of interrupt vectors in each device is fixed, so I cannot create anymore. According to the Hi-Tech C manual: So basically, I have to put all desired code in one interrupt function like this: void interrupt ISR(void) { if(RBIF) //If interrupt flag bit is 1 {...
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