Hi,
I have purchased a PCA9685. I want to be able to pulse the output pins. I didn't notice in the wiki until the item has arrived that the instructions say:
Command Value Extra information
PCAPWM,<pin>,<value> 0...4095 Control PCA9685 pwm level.
PCFGPIO,<value> 1,0 Control PCF8574 output pins.
PCFPulse,<pin>,<value>,<duration> 1,0 Pulse control on PCF8574 output pins (duration in mS, MILLIseconds)
PCFLongPulse,<pin>,<value>,<duration> 1,0 Pulse control on PCF8574 output pins (duration in S, seconds)
I assumed that PCAPulse,<pin>,<value>,<duration> would work to pulse the pins... However I get a json error as follows:
Unknown or restricted command!
When I use: "PCF" and put my meter on the pin it remains at ~3v.
I've also tried setting one of the pins to 0 with:
PCFGPIO,<value>
http://192.168.1.145/control?cmd=PCFGPIO,11,0
I get the json conformation back that the pin has been set to 0:
{
"log": "GPIO 11 Set to 0",
"plugin": 19,
"pin": 11,
"mode": "output",
"state": 0
}
But when I put my meter accross the GND and V+ there is still ~3v.
Any idead what I am doing wrong? I can correctly adjust PWM from 0 to 4095 (using the yellow pwm pin on the PCA9685). I have wired the PCA9685 as follows:
GND to GND
OE to nothing
SCL to GPIO2 (d4)
SDA to GPIO0 (d3)
VCC to nothing
V+ 3V
Many thanks for any help!
John
PCA9685 pulse GPIO pins
Moderators: grovkillen, Stuntteam, TD-er
Re: PCA9685 pulse GPIO pins
Hm...
Did you mix up PCF8574 and PCA9685?
PCF8574 is a GPIO extender. It can do most things similar to the ESP's GPIOs, trigger a pulse of given length, set to on or off and so on.
It can be used as an input too.
PCA9685 is a PWM (Pulse width modulation) driver chip for LED's and PWM driven servos.
This chip generates it's own PWM signal independently from the ESP. Only the parameters
e.g. the pulse-duty factor for the PWM are sent from the ESP to the PCA9685 via I²C.
I don't think it is possible to send a single defined pulse from the PCA9685 as it is from the PCF8574 at all.
Regards
Shardan
Did you mix up PCF8574 and PCA9685?
PCF8574 is a GPIO extender. It can do most things similar to the ESP's GPIOs, trigger a pulse of given length, set to on or off and so on.
It can be used as an input too.
PCA9685 is a PWM (Pulse width modulation) driver chip for LED's and PWM driven servos.
This chip generates it's own PWM signal independently from the ESP. Only the parameters
e.g. the pulse-duty factor for the PWM are sent from the ESP to the PCA9685 via I²C.
I don't think it is possible to send a single defined pulse from the PCA9685 as it is from the PCF8574 at all.
Regards
Shardan
Regards
Shardan
Shardan
Re: PCA9685 pulse GPIO pins
Indeed, I think I have mixed up these two boards. I thought the PCA9685 could do what the PCF8574 could do and more...
I was checking before I ordered a PCF8574.
Oh well, should have read first, and bought second!
Thanks
John
I was checking before I ordered a PCF8574.
Oh well, should have read first, and bought second!
Thanks
John
Re: PCA9685 pulse GPIO pins
You're still buying second
(happens to all of us)
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