Hello I am doing a project using the mini2440 in which I am going to control the home appliances using the mini2440 and for that I want a relay board which can be easily interfaced with my mini2440. So can you guys help me in designing of such a board which can be easily interfaced with mini 2440 . Thank you
We have just made a gpio pcb with 2 relay output & 6 digital optocoupled inputs (+ a mifare card reader on the I2C bus). Also an onboard DC/DC power supply can be used to power the mini2440 from anything between 12v & 35v DC. I have attached the schematic so you can use it as a starting point. This is only at proto stage, so no garantee it's fully working. Good luck, Laurent
Thank you Laurent for this schematic I am very much grateful to you for this. But if posibble can you provide me the How-to of this relay board so that I can know that how to use this relay board and also the eagle schematics rather than pdf file . Thank you
just to let you know that we have finished our gpio board and published some source code and demo : http://www.tritechbelgium.com/content/mini2440-gpio-interface-board I think the part about polling inputs via blocking calls to poll should be interesting enough to post the link here.
hi Piyush i can suggest you the USB_IO board available at http://www.eko-fpga.com http://eko-fpga.com/index.php?option=com_content&view=article&id... but she need a full compliant HID driver . regards phil
Hello, I've patched the kernel to enable GPIO driver. Now i have working driver for it. But my problem is that i am not able to find GPIO port number for the AIN0 to AIN4 pins & GND pin on schemtic diagram of the 2mm pitch 34 pin GPIO. There are only 28 pins which have function as GPIO pins. Is there any way to use all 34 pins as GPIO pins ? Regards, Sanjay
As far as i can tell, there are no 34 gpio available on the connector. 3 pins are used for power, 1 for Reset, this leaves 30 i/o. From those 30, 4 are analogic. You could eventually use them as a pseudo digital input by software (ie, compare the analog value to a trigger level), but i wouldn't do that. This leaves 26 gpio. From those, a few have selectable functions (i2c, spi, ...) that need some work to be disabled (i think about i2c for example which is enabled by default in the kernel). Check http://members.cox.net/ebrombaugh1/embedded/mini2440/index.html for a nice pinout table. So, if you really need so many gpio, i would go for another way. By, for example, using i2c gpio expanders (pcf8574 from memory) or by multiplexing lines. What is your target application ? Do you mainly need input or outputs ?
Laurent, Thanks for the reply. I need mainly outputs . My target application is Galvo base laser marking machine. Right now i am using USB FPGA's IO. I want to replace it by using GPIOs. Please also suggest me the clocks for the GPIOs on mini2440. I've read the manual which mentions the 67MHz clock for PCLK. How can i achieve that clock ? Is there any better options available ? Also there are some 20 GPIOs on 40 pins system bus interface. If i combine both the GPIOs then Is it possible to achieve same clock on both ? Best Regards, Sanjay
I don't remember pclk value, but it's something like around 50Mhz. However, why so many outputs for a galvo laser ? I can see 1 output for each mirror + 1 output to toggle laser beam on/off or even to modulate its power, that's 3 output in total. mini2440 comes with 4 pwm timers connected to GPB0...3, GPB0...1 beeing easily available on the 34 pin connector. How are your mirrors controlled ? pwm ? analog ? digital ? As for clock speed, i don't understand your question ? What frequency do you need on your io ? What are the outputs actually used for ? From user space don't expect anything lower than a few ms with a lot of jitter. From kernel space, you can reach down the few 10µS, and much less if you use the pwm modules. Can't help much more i'm afraid.
I want to controlled mirros digitally else 3 IO are sufficient. regards
Hi guy I have prototype the Milty peripheral control board, by which you can add 1024(8bit) input and 1024 output(8 bit) using con5. So the I/O's are no more problem. u can contact on seeco_pak@yahoo.com for further details.