Hi guys. I have gather several questions concerning some stuff i have in my mind and i thought maybe you could help. So, 1) Lets suppose we have two circuits one measuring temperature and showing it in an lcd screen and one, say, measuring another temperature or something else and showing it in an lcd screen. Is it possible to combine them together to show both temperatures in one lcd screen or change between temps using a button or something? 2) Does anyone know of any circuit to control fans using an lcd screen (to display current setting) and buttons to adjust the fan speed? 3) Most project i find around the net use lcds. Is it a lot different to use vfds instead of lcds? Hmm, I had more questions. I ll post again if i remember them. Thats it for now. Thanks
Just remembered one of them. I saw that a lm3915 can be used to output the current voltage in a led array or in an lcd/vfd. I am aware how this could be done with leds but how about lcds and vfds? thanks
For temps, do you mean a LCD temperature module, or for example a 20*2 alphanumeric LCD? Easyest way imo is to put a switch in to change the thermistor To do more we need to know more about it - how is the temp read and interfaced to the lcd?
ok. what i want to do is an autonomous system to measure temps (2-3 different temps), voltages, control fans etc. showing everything to an lcd/vfd. I know that this is very difficult for a newbie in electronics like me but i thought i can try to experiment starting at solving the questions i have. i know how to do each circuit individually but i dont know how to combine them together. So here i start again 1) Say i have a system based on this circuit. Also, say that i use an lm3915 to show the voltage in a bar-like graph in the lcd. How can i combine these two together in order to get ONE system with ONE lcd where i can change between the above circuits. Like pressing a button or so and change to temperatures, or press again and go back to voltage bar graph. Is this possible? 2) Does anyone know of any circuit to control fans using an lcd screen (to display current setting) and buttons to adjust the fan speed?
As i said above. I am quite a newbie when it comes to electronics. i know some stuff but nothing fancy. So, what do ou mean by a pic 16 ot atmega? any online examples or something?
give people a chance to awnser. the schematic you linked to uses a national semiconder microcontroller. Often called a uC a microcontroller is a small processor, that has memory and ram all in the same package. This means its just that one chip you need. Most have FLASH eeprom memory now, this is great, as its erasable, and programable, by an electrical signal. The most common micro to be used by hobbiests is a PIC from arazona microchip www.microchip.com They have 3 flavours of the PIC, low end (called a 12 series) mid range (called a 16 series) and high end (18 series). mid range are cheap, and fairly fast, making the programming easyer. They have neato built in hardware that can make serial communication, and analouge reading a doddle. they are easy to program, a ponyprog or a JDM can be built for about $8. there is a powerful FREE IDE (integrated dev. environment). (atmels are kinda similar, but i won't go into them here, as i don't think they make a best first micro). A x86 machine uses the Von Nueman architecture, this means it has the same program and data memory (you only have one place for RAM). These micros don't, they use Harvard architecture, in this they have sperate program and data memory, which means you can access both at the same time, so while its only 8bit micro, running at 20mhz clock, it has quite good perfomance, (can execute instructions at 5mhz). A PIC16 range device should cost around £2 GBP in single quantities. There are lots of differnt ones, with differnt number of pins, program and data memory, also with differnt hardware onboard. So have a google for a PIC guide, and look at www.microchip.com would be the easyest way of doing what you want.
Great. I have started researching some stuff on the pic16 (any online tutorials or other links would be great). I am studying comp.sci. so i know most of the stuff needed from the programming side of view (i dont know if the instruction set for the pics is different in asm). I just need some more specific info on pics. Thanks
YES YES. like this. at least this replies my digital fan controller question. cheers mate. EDIT: Having a second look, it doesnt have any schematics or anything so its not really that useful.
I'll make a special effort to do this for you guys in my half week off after exams. I could provide pre-programmed PICs and a schematic that's what you're after JohnFish. Last exam is on 31st Jan, so could do it that evening.
thanks man. and dont worry. take as much time you want. meanwhile i ll read some stuff myself. cheers
1) if you use a DPDT switch you can switch between thermocouples (temp. probes) unfortunately i cannot understand PIC's, i tried to read a tutorial on them and ended up with a nosebleed and an excedrin migraine
There are quite a few ADC's on the PICs now adays, if thats not enough you can always buy sensor ICs that are designed to work on a bus like I2C. This makes it very easy.
