reef-pi :: An opensource reef tank controller based on Raspberry Pi.

[Schreiber]

On the topic of PCA9685... I can use the PWM output from the PCA for the L293d Enable, correct? That would free up a couple of GPIO pins for me if that's the case.

Yes

How do I set these jacks up in my configuration? I'm wanting to use outputs 12 & 13 from the PCA9685 as my PWM outputs for EN 1,2 & EN 3,4 on the L293D. In the Adafruit guide, pins 0 & 1 are being used with the RPi as the driver. I know I have to switch my driver to PCA9685, but are the pins I need to use 12 & 13? Or is the numbering scheme different here as well (like on the Pi, GPIO 18 is "pin 0"? I remember having a lot of trouble with the jacks when I was using the wrong pin in my previous build & I'm wanting to avoid that headache again!

 

[sfgabe]

How do I set these jacks up in my configuration? I'm wanting to use outputs 12 & 13 from the PCA9685 as my PWM outputs for EN 1,2 & EN 3,4 on the L293D. In the Adafruit guide, pins 0 & 1 are being used with the RPi as the driver. I know I have to switch my driver to PCA9685, but are the pins I need to use 12 & 13? Or is the numbering scheme different here as well (like on the Pi, GPIO 18 is "pin 0"? I remember having a lot of trouble with the jacks when I was using the wrong pin in my previous build & I'm wanting to avoid that headache again!

I use an L293D (H-bridge board) for exactly this to power my doser pump motors. The pins are entered into reef-pi as 0,1,2,3,4, etc just like the rpi driver, but there's more of them. You'll need 6 pins, ENA, 1, & 2, and ENB, 3, & 4 - which for me are 0,1,2,3,4,& 5 on the PCA9685. If you're powering something like a motor, EN will be the "power" switch and then you'll either end up with 1 dummy pin that's always set to "off" or be able to switch between forward and reverse by turning one high and one low and vice versa.

 

[Schreiber]

I use an L293D (H-bridge board) for exactly this to power my doser pump motors. The pins are entered into reef-pi as 0,1,2,3,4, etc just like the rpi driver, but there's more of them. You'll need 6 pins, ENA, 1, & 2, and ENB, 3, & 4 - which for me are 0,1,2,3,4,& 5 on the PCA9685. If you're powering something like a motor, EN will be the "power" switch and then you'll either end up with 1 dummy pin that's always set to "off" or be able to switch between forward and reverse by turning one high and one low and vice versa.

Interesting. I had been under the impression you had to use the GPIO pins for the Inputs on the L293D, because the PCA9685 was set to a much higher frequency.

So, if the PCA9685 outputs can be used in this way, what's keeping us from using them to control relay outputs as well?

 

[Spathodus]

Thank you so much for the kind words. It means everything to me and rest of the folks who makes this project possible.

I think this is a bug in the pca9695 driver where we are not sending special instruction for 0 duty_cycle. https://github.com/reef-pi/reef-pi/issues/794
I plan to fix it as part of 3.0 release. If possible use a timer to cut off the power during off cycle.

Thank you for your quick response. I might route the incoming driver power through a timed relay then.

 

[sfgabe]

Interesting. I had been under the impression you had to use the GPIO pins for the Inputs on the L293D, because the PCA9685 was set to a much higher frequency.

So, if the PCA9685 outputs can be used in this way, what's keeping us from using them to control relay outputs as well?

As far as I understand, the PCA9685 is specifically for things that require a PWM signal (different from frequency), so basically leds and servos only.

 

[Ranjib]

How do I set these jacks up in my configuration? I'm wanting to use outputs 12 & 13 from the PCA9685 as my PWM outputs for EN 1,2 & EN 3,4 on the L293D. In the Adafruit guide, pins 0 & 1 are being used with the RPi as the driver. I know I have to switch my driver to PCA9685, but are the pins I need to use 12 & 13? Or is the numbering scheme different here as well (like on the Pi, GPIO 18 is "pin 0"? I remember having a lot of trouble with the jacks when I was using the wrong pin in my previous build & I'm wanting to avoid that headache again!

You need only two pwm pins, en1 and en2. IN1/2/3/4 all can be connected to pi GPIO if you want to contol the moto diection. For LEDs it does not make sense. You can just hook them up to 3.3V rail and GND,

 

[sfgabe]

You need only two pwm pins, en1 and en2. IN1/2/3/4 all can be connected to pi GPIO if you want to contol the moto diection. For LEDs it does not make sense. You can just hook them up to 3.3V rail and GND,

If you want dimming ability on LEDs it sometimes makes sense to use a PWM signal.

 

[Ranjib]

As far as I understand, the PCA9685 is specifically for things that require a PWM signal (different from frequency), so basically leds and servos only.

with 3.0 , we will be able to use pwm outputs as notmal digital output. In that case its basically 100% duty cyle or 0% duty cycle. So L293D could be entirely driven by pca9685 IC, or even relay contol. I have not tested this, theres a pca9685 driver bug that also i need to fix before i start field testing

(bug)treat 0 and 100% setting differently in pca9685 driver by ranjib · Pull Request #39 · reef-pi/drivers

github.com

(feat)make pwm channels work as digital output as well by ranjib · Pull Request #7 · reef-pi/hal

github.com

 

[Ranjib]

If you want dimming ability on LEDs it sometimes makes sense to use a PWM signal.

yes, and thats why en1, en2 is the pwm input. Rest does not need to be, IN1/2/3/4 all can be simple 3.3v/GND

 

[Urtoo]

HS300 is in hand. After maleficent movie night, I will solder a header to the pi zero and start getting running.
Pictures will be in my build thread, maybe tomorrow after RAP.
Speaking of which, anyone in here going tomorrow?

 

[Ranjib]

HS300 is in hand. After maleficent movie night, I will solder a header to the pi zero and start getting running.
Pictures will be in my build thread, maybe tomorrow after RAP.
Speaking of which, anyone in here going tomorrow?

Nope. Was in orlando.

 

[Ranjib]

As far as I understand, the PCA9685 is specifically for things that require a PWM signal (different from frequency), so basically leds and servos only.

with 3.0 , we will be able to use pwm outputs as notmal digital output. In that case its basically 100% duty cyle or 0% duty cycle. So L293D could be entirely driven by pca9685 IC, or even relay contol. I have not tested this, theres a pca9685 driver bug that also i need to fix before i start field testing

(bug)treat 0 and 100% setting differently in pca9685 driver by ranjib · Pull Request #39 · reef-pi/drivers

github.com

(feat)make pwm channels work as digital output as well by ranjib · Pull Request #7 · reef-pi/hal

github.com

 

[Ranjib]

reef-pi 3.0 new pwm profiles:
Fixed: Constant intensity for given time period

Interval: Linear interpolation of a set of intensities at used defined fixed time interval. (Like auto in reef-pi 2.0, but can be used with arbitrary time intervals, like 15 min).

Diurnal:

Sine:

Random:

Lunar: Like sine in daily intensity cycle, but max intensity changes with 27 days cycle. Graph is for three months. Each peak representing a daily sine cycle

Composite: A set of sub-profiles each with a specific duration and min/max intensity. The example graph combines aiurnal, sine, random and fixed profiles.

These things are now present in the backend/controller. We are working on building the UI.

 

[Ranjib]

For reference: https://github.com/reef-pi/reef-pi/issues/859

 

[Urtoo]

After too long of a delay... I am starting

first to solder some pins to my pi zero. I will overload my build thread with photos

 

[Urtoo]

Now with headers...

after uploading this, I touched the two that were not good a moment ago.

 

[ambientaquatics.adam]

Oops

 

[Ranjib]

Now with headers...

after uploading this, I touched the two that were not good a moment ago.

Is it working now?

 

[Bigtrout]

reef-pi 3.0 new pwm profiles:
Fixed: Constant intensity for given time period

Interval: Linear interpolation of a set of intensities at used defined fixed time interval. (Like auto in reef-pi 2.0, but can be used with arbitrary time intervals, like 15 min).

Diurnal:

Sine:

Random:

Lunar: Like sine in daily intensity cycle, but max intensity changes with 27 days cycle. Graph is for three months. Each peak representing a daily sine cycle

Composite: A set of sub-profiles each with a specific duration and min/max intensity. The example graph combines aiurnal, sine, random and fixed profiles.

These things are now present in the backend/controller. We are working on building the UI.

This is something im really waiting for!

In other news, no problems whatsoever to report. My reef-pi just keeps humming happily along!

 

[Schreiber]

So I'm working with a PCA9685pw & it's driving me up the wall. I can get Adafruit's PCA9685 board to work, but when I try mine, it crashes.

Main PID: 981 (code=exited, status 1/FAILURE)

The weird thing to me is that using i2cdetect, I find the PCA9685 on 0X41 (I have address pin A0 jumpered, so this is expected). So the pi is seeing the chip, but reef pi still doesn't like it.

Using journalctl:
sudo journalctl -fu reef-pi.service
-- Logs begin at Thu 2019-02-14 05:12:02 EST. --
Oct 25 23:25:59 control1 systemd[1]: reef-pi.service: Failed with result 'exit-code'.
Oct 25 23:27:29 control1 systemd[1]: reef-pi.service: Service RestartSec=1min 30s expired, scheduling restart.
Oct 25 23:27:29 control1 systemd[1]: reef-pi.service: Scheduled restart job, restart counter is at 2.
Oct 25 23:27:29 control1 systemd[1]: Stopped raspberry pi based reef tank controller.
Oct 25 23:27:29 control1 systemd[1]: Started raspberry pi based reef tank controller.
Oct 25 23:27:29 control1 reef-pi[995]: 2019/10/25 23:27:29 Setting pca9685 frquency: 1500
Oct 25 23:27:29 control1 reef-pi[995]: 2019/10/25 23:27:29 ERROR: Failed to initialize pca9685 driver with mock i2c bus. Error: remote I/O error
Oct 25 23:27:29 control1 reef-pi[995]: 2019/10/25 23:27:29 ERROR: Failed to initialize controller. Error:remote I/O error
Oct 25 23:27:29 control1 systemd[1]: reef-pi.service: Main process exited, code=exited, status=1/FAILURE
Oct 25 23:27:29 control1 systemd[1]: reef-pi.service: Failed with result 'exit-code'.
Oct 25 23:28:59 control1 systemd[1]: reef-pi.service: Service RestartSec=1min 30s expired, scheduling restart.
Oct 25 23:28:59 control1 systemd[1]: reef-pi.service: Scheduled restart job, restart counter is at 3.
Oct 25 23:28:59 control1 systemd[1]: Stopped raspberry pi based reef tank controller.
Oct 25 23:28:59 control1 systemd[1]: Started raspberry pi based reef tank controller.
Oct 25 23:28:59 control1 reef-pi[1027]: 2019/10/25 23:28:59 Setting pca9685 frquency: 1500
Oct 25 23:28:59 control1 reef-pi[1027]: 2019/10/25 23:28:59 ERROR: Failed to initialize pca9685 driver with mock i2c bus. Error: remote I/O error
Oct 25 23:28:59 control1 reef-pi[1027]: 2019/10/25 23:28:59 ERROR: Failed to initialize controller. Error:remote I/O error
Oct 25 23:28:59 control1 systemd[1]: reef-pi.service: Main process exited, code=exited, status=1/FAILURE
Oct 25 23:28:59 control1 systemd[1]: reef-pi.service: Failed with result 'exit-code'.