- Sun Oct 23, 2016 6:58 pm
#57009
So I built a wifi smart plug using an ESP8266-01. The program is generic, using GPIO0 and GPIO2 to turn on (high) and off (low) a simple LED. No worries with the program.
My problem is, I tried to design a board to make assembly easier, and something I have done is causing the ESP to not start up. Rather, the red LED comes on and stays on. The serial monitor shows no communication.
If I disconnect GPIO2 from its opto and leave GPIO0 connected to its opto, I get the following serial monitor feedback:
ets Jan 8 2013,rst cause:2, boot mode:(1,6)
If I connect GPIO2 to its opto and disconnect GPIO0 its opto, I get the following feedback:
ets Jan 8 2013,rst cause:2, boot mode:(2,6)
Fatal exception (0):
epc1=0x40100002, epc2=0x00000000, epc3=0x00000000, excvaddr=0x00000000, depc=0x00000000
(this just keeps repeating endlessly)
In short, the design (Eagle file attached) connects GPIO0 to a MOC3021 via a 1k resistor. The MOC3021 then connects to a BT137 triac via a 220ohm resistor to drive the mains. (Same setup for GPIO2). Although, I have not actually finished building the circuit beyond the optocouplers. I don't have any triacs on hand at the moment.
I'm obviously missing something pretty simple, but I don't see it. I must be pulling the pins low and don't understand how/why. Shouldn't the MOC3021 not allow the pin to be connected to ground, but rather, only allow the pin, when high, to trigger the MOC?
I've seen most designs use a transistor as part of the drive circuit, but I am novice enough not to understand why. I've made many home made SSRs using the same opto/triac combination and never had problems with a pin being driven low for other chips (typically PICs).
I sure could use some help. I'm trying to keep this board as tiny as possible so it will fit inside the junction box, along with a small 3.3v power supply.
Thank you in advance for your assistance.
My problem is, I tried to design a board to make assembly easier, and something I have done is causing the ESP to not start up. Rather, the red LED comes on and stays on. The serial monitor shows no communication.
If I disconnect GPIO2 from its opto and leave GPIO0 connected to its opto, I get the following serial monitor feedback:
ets Jan 8 2013,rst cause:2, boot mode:(1,6)
If I connect GPIO2 to its opto and disconnect GPIO0 its opto, I get the following feedback:
ets Jan 8 2013,rst cause:2, boot mode:(2,6)
Fatal exception (0):
epc1=0x40100002, epc2=0x00000000, epc3=0x00000000, excvaddr=0x00000000, depc=0x00000000
(this just keeps repeating endlessly)
In short, the design (Eagle file attached) connects GPIO0 to a MOC3021 via a 1k resistor. The MOC3021 then connects to a BT137 triac via a 220ohm resistor to drive the mains. (Same setup for GPIO2). Although, I have not actually finished building the circuit beyond the optocouplers. I don't have any triacs on hand at the moment.
I'm obviously missing something pretty simple, but I don't see it. I must be pulling the pins low and don't understand how/why. Shouldn't the MOC3021 not allow the pin to be connected to ground, but rather, only allow the pin, when high, to trigger the MOC?
I've seen most designs use a transistor as part of the drive circuit, but I am novice enough not to understand why. I've made many home made SSRs using the same opto/triac combination and never had problems with a pin being driven low for other chips (typically PICs).
I sure could use some help. I'm trying to keep this board as tiny as possible so it will fit inside the junction box, along with a small 3.3v power supply.
Thank you in advance for your assistance.
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