- Thu May 21, 2015 5:08 pm
#18121
I am currently working on an esp8266-01 based rgb led dimmer and plan to do a esp8266-12 rgbw dimmer next. If you guys are interested I can post here once I get it to work. On the breadboard the basics for the first version already worked 
I got ony problem though at the moment (perhaps you already solved this with your design). GPIO0/2 and RX control the mosfets for the led channels. They need to be tied to ground so that no random light "spikes" can occur. The problem here is that I can't tie GPIO0 to ground and then restart the module because then it will go into flashmode. Any idea how to avoid this?
I got ony problem though at the moment (perhaps you already solved this with your design). GPIO0/2 and RX control the mosfets for the led channels. They need to be tied to ground so that no random light "spikes" can occur. The problem here is that I can't tie GPIO0 to ground and then restart the module because then it will go into flashmode. Any idea how to avoid this?
- Sat May 23, 2015 5:53 am
#18242
That's a tough issue.. I'm not familiar with a solution that will pull up the wire for the GPIO pin, but pull it down for the MOSFET at the same time.
In the design in this topic GPIO13 is used, which isn't needed by the boot sequence so we can just pull that pin down. That's why I love the ESP-12, it has a lot more usable pins than some of the other modules.
In the design in this topic GPIO13 is used, which isn't needed by the boot sequence so we can just pull that pin down. That's why I love the ESP-12, it has a lot more usable pins than some of the other modules.
- Tue May 26, 2015 12:15 pm
#18523
One way to do this is by driving the MOSFET through a bipolar NPN that has a pullup on it base. I use a 2k pullup, a 20 k base resistor and a 10 k from collector to 12V. My transistor is a 2N2222 which costs "nothing", so it is only the extra hassle to mount the four extra components. As an added bonus I can use lower cost MOSFETS that cannot be driven into relatively good saturation by 3.3V.
With this circuitry GPIO0/2 from an ESP-01 drives my LEDs. Note though that the transistor driver inverts the signal, so that LED is on when GPIO is low and vice versa. You I advise you to adjust the program running on the ESP-01, so that this becomes invisible from the unit controlling the ESP.
LastSamurai wrote:I am currently working on an esp8266-01 based rgb led dimmer and plan to do a esp8266-12 rgbw dimmer next. If you guys are interested I can post here once I get it to work. On the breadboard the basics for the first version already worked
I got ony problem though at the moment (perhaps you already solved this with your design). GPIO0/2 and RX control the mosfets for the led channels. They need to be tied to ground so that no random light "spikes" can occur. The problem here is that I can't tie GPIO0 to ground and then restart the module because then it will go into flashmode. Any idea how to avoid this?
One way to do this is by driving the MOSFET through a bipolar NPN that has a pullup on it base. I use a 2k pullup, a 20 k base resistor and a 10 k from collector to 12V. My transistor is a 2N2222 which costs "nothing", so it is only the extra hassle to mount the four extra components. As an added bonus I can use lower cost MOSFETS that cannot be driven into relatively good saturation by 3.3V.
With this circuitry GPIO0/2 from an ESP-01 drives my LEDs. Note though that the transistor driver inverts the signal, so that LED is on when GPIO is low and vice versa. You I advise you to adjust the program running on the ESP-01, so that this becomes invisible from the unit controlling the ESP.
