lcd Microcontrollers - Page 1
Forum section: electronics / general

author: jaRON
author_rank: Contributor
timestamp: April 03, 2011, 09:36:11 pm
content: I'm going to make a fan controller ues the Serial TFT LCD 3.2" with Touchscreen. I make a fan conroler a use the Microcontrollers PICAXE 20X2 Microcontroller (20 pin). the fan conroler is going to run 17 fans. I need help with getting the fan speed to come up no the lcd. i like to have so you can move the speed of the fan speed one at time using the Touchscreen.

author: neoone
author_rank: Regular Contributor
timestamp: April 03, 2011, 10:23:19 pm
content: what exactly is your problem ? Do you have the LCD and/or touch panel running yet ?

author: PeterG
author_rank: Frequent Contributor
timestamp: April 03, 2011, 11:12:24 pm
content: jaRON, let me see if i got this. You want to build a fan controller that will control 17 fans independently via a 3.2 inch LCD touch screen.I would research other options to Picaxe, this project may fall outside of Picaxe limits. I would recommend any of the PIC Compilers available.I also believe you could do this with a single 40pin PIC depending on how the LCD communicates(Serial, Parallel,I2C etc).Regards

author: Psi
author_rank: Super Contributor
timestamp: April 04, 2011, 12:43:32 am
content: yeah, a PIXAXE isn't powerful enough, especially if you plan to use that sparkfun lcd+touchscreen

author: dimlow
author_rank: Frequent Contributor
timestamp: April 04, 2011, 01:09:52 am
content: What i did with my fan controller was to control the fan speed with a software PWM (Only 8 Channels)I used the fan sense of the fan with a pull up to VDD, then when it came time to measure the fan speed I set a timer running, stopped the PWM of the fan, then timed three pulses from the fan sense, restarted the PWM and calculated the RPM from the average duration on the pulse width. This gave quite a stable RPM reading. If your using PWM to control the speed of the fans you have to stop the PWM before you measure the RPM otherwise you will get false readings from the PWM on the sense wire of the fan. As your only stopping the PWM for a small friction of time, the fan dose not have time to slow down before you have finished timing the pulses.Edit: oh i had trouble controlling 8 fans with PWM and reading temp sensor and fan speed with the PIC i used. I got it wrong when i told you i used the 18f4550, it was in fact a 16f877A running at 20 Mhz. You have to run quite a fast PWM frequency to stop the audible noise from the PWM, i only just managed this with the 16f877. The PIXAXE just wont cut it for 17 Fans. For so many fans id suggest running maybe one pic for the display and the control of the system, then daughter boards running maybe 8 fans each with thier own PIC. To run 8 fans with pwm, you will need 16 IO's. 8 for the PWM and 8 for the RPM sense. So 17 Fans is going to cost you 34 IOs then maybe 8 for the LCD and another 3 for the Touch screen. Simple not possible on the PIXAXE.BIG TIP: Start small then expand on what you have learnt

author: dimlow
author_rank: Frequent Contributor
timestamp: April 04, 2011, 01:34:05 am
content: The Attached doc tells you all you need to know.

author: PeterG
author_rank: Frequent Contributor
timestamp: April 04, 2011, 01:37:53 am
content: One option may be to use a dedicated fan control I.C. (maybe a set of MAX6870 or similar) using a PIC 18F2550 or similar to control the controllers via I2C.I am thinking it would be a timing nightmare to run 17 software wpm channels AND run the GUI.Regards

author: dimlow
author_rank: Frequent Contributor
timestamp: April 04, 2011, 01:45:47 am
content: It never entered my head to use a fan controller IC, i wanted to do all the work myself as it was just a five minute project i thought! Not So.

author: jaRON
author_rank: Contributor
timestamp: April 04, 2011, 08:04:07 pm
content: I know how to make a fan controller using a microcontroller. What I need help with is using a microcontroller to run the lcd and how to get lcd Touchscreen to control fan controller. and for the speed to come up on the lcd. I need help with programming of the microcontrollernad the lcd TouchscreenP.S I have not found a programer for lcd Touchscreen

author: dimlow
author_rank: Frequent Contributor
timestamp: April 04, 2011, 09:36:50 pm
content: Quote from: jaRON on April 04, 2011, 08:04:07 pmWell ok good luck with it.

author: PeterG
author_rank: Frequent Contributor
timestamp: April 04, 2011, 09:58:17 pm
content: jaRON, i have never seen an LCD 'Programmer'. LCDs are controlled by the mcu, there are some with a limited flash memory for storing images but thats about it. You will need to develop the the firmware for the mcu to get the display to work as you intend. Ideally you will use HARDWARE interrupts to handle the touch panel responses, however i dont think Picaxe gives you access to the Hardware interrupts.To get the display working you will need to read the documentation for the display. Once you get that working, then start on the touch panel input handling. Once you have that done, you will understand the overhead a LCD and Touchpad put on a mcu.Regards

author: jaRON
author_rank: Contributor
timestamp: April 06, 2011, 08:25:56 pm
content: i looking for a Microcontrollers that i can run 17 fans on and a lcd touch screen I like to have 25 out and 10 in. What is the best Microcontrollers.

author: PeterG
author_rank: Frequent Contributor
timestamp: April 06, 2011, 09:16:56 pm
content: I would start with the Microchip website.http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2551I would not use anything below a PIC18 for this project.Regards

author: Unknown
author_rank: Unknown
timestamp: April 06, 2011, 09:23:57 pm
content: What's wrong with parametric searches? There is no best in engineering without proper specs. Almost any uC vendor will have some suitable product. Having enough RAM for a frame buffer might be helpful.

author: PeterG
author_rank: Frequent Contributor
timestamp: April 06, 2011, 09:46:18 pm
content: The page i posted has links to parametric searches for each PIC Family.Regards

author: jaRON
author_rank: Contributor
timestamp: April 10, 2011, 04:32:50 am
content: do I need to have a Microcontrollers on the fan controller . the led has a 4d labs goldelox-sgc on it

author: Bored@Work
author_rank: Super Contributor
timestamp: April 10, 2011, 06:32:03 am
content: Quote from: alm on April 06, 2011, 09:23:57 pmIt means having to do some work. And we can't have work between jaRON's idea and its realization. Instant gratification, you know?