From: Gerald Coley <[email protected]> Reply-To: "[email protected]" <[email protected]> Date: Monday, July 7, 2014 at 1:19 PM To: "[email protected]" <[email protected]> Subject: Re: [beagleboard] Using Relay Module With BBB
> These transistors, they are active low. We can only sink and drive 6mA. You > could try adding a pullups to each signal to pull the voltage higher, Tie then > to 3.3V. I think your initial assessment was correct. If VCC is 5V or higher, there is no way to switch these transistors off. This relay board design isn¹t suitable for the BBB. Best to replace the PNP transistors with NPN and swap the power pins. GND now becomes 5V/12V and the VCC now becomes 0V. Probably have to turn the LEDs around. Regards, John > > Gerald > > > On Mon, Jul 7, 2014 at 2:51 PM, <[email protected]> wrote: >> http://www.wlelectronix.com/Content/Images/uploaded/Relay%208%20Way_2.png >> My relay module is must be something like this. >> Relays are 5v, so i use VDD_5V(P9_05) to drive them. GPIO turns on and off >> them in normal. But there is a problem in my situation. I'm trying to find >> it. >> >> 7 Temmuz 2014 Pazartesi 15:58:52 UTC+3 tarihinde Gerald yazdž: >>> I can't tell much from a picture. Doe sit have a schematic, or a link to >>> one? >>> >>> If the relays are 5V, then you cannot drive them from a GPIO as it is 3.3V >>> and delivers only about 6mA.. Connecting 5V will blow the processor. You >>> would need a level shifter such as a transistor to drive the relay.. >>> >>> >>> Gerald >>> >>> >>> >>> >>> On Mon, Jul 7, 2014 at 7:37 AM, <[email protected]> wrote: >>>> Hello, >>>> I'm trying to use relay module with beaglebone black. >>>> I bought relay module from china. >>>> It is very similar to this: >>>> http://www.hobbyist.co.nz/sites/default/files/8ChannelRelay_small%20%28Cust >>>> om%29.jpg >>>> <http://www.hobbyist.co.nz/sites/default/files/8ChannelRelay_small%20%28Cus >>>> tom%29.jpg> >>>> I have connected VCC to BBB's VDD_5V(P9_05) and GND to BBB's DGNG(P9_01). >>>> Here is the problem: >>>> When I connect any gpio port to relay module's any signal pin, relay is >>>> starting to work. >>>> Even GPIO is high or low I can't switch off the relay. So I can't control >>>> any relay from BBB. >>>> What can I do to solve this problem? >>>> Many thanks. >>>> Note: I tried relay module with external power source but results are same. >>>> -- >>>> For more options, visit http://beagleboard.org/discuss >>>> --- >>>> You received this message because you are subscribed to the Google Groups >>>> "BeagleBoard" group. >>>> To unsubscribe from this group and stop receiving emails from it, send an >>>> email to [email protected]. >>>> >>>> For more options, visit https://groups.google.com/d/optout >>>> <https://groups.google.com/d/optout> . >>> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. > > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
