Adafruit 16-Channel 12-bit PWM/Servo Driver

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adafruit_support_bill
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by adafruit_support_bill »

I don't know the Write8 function
It is defined in the same file:

Code: Select all

void Adafruit_PWMServoDriver::write8(uint8_t addr, uint8_t d) {
  Wire.beginTransmission(_i2caddr);
  Wire.write(addr);
  Wire.write(d);
  Wire.endTransmission();
}

Donpi
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by Donpi »

Ouhouuu it works...

My wireing was wong in the servo driver side.

Everything works fine.

Thank you.

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jofegibo
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by jofegibo »

I've got a problem,

I connected my driver to my beaglebone Black And I was aware in connecting it the right way (battery to terminal block, SCL to SCL in the BBB , SDA to SDA in the BBB, Vcc to 3v3 pin in the BBB and the ground to the ground in the BBB) when I turned on everithing was fine but later when I was programming the PWM, LED no longer turned on and servo didn't work.

I cheked with I2cdetect and It it's still apears the number 40 in the table, but not the number 70.

Is the Driver damaged??

Help me please!!!

P.D. Sorry, I'm not good with my english

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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by adafruit_support_bill »

Post some photos showing your soldering and all your connections to the BBB.

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adafruit_support_rick
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by adafruit_support_rick »

Check your wiring. Sometimes, with poor electrical connections, the device will show up in i2cdetect, but it will fail to operate.

If you post some detailed pictures of both sides of your board, and of your wiring to the BBB, we will have look.

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jofegibo
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by jofegibo »

Image

The white wire is connected to P9_19 (SCL) and the green one to P9_20 (SDA).
The black wire is connected to P8_2 (GND) and the red one to P8_4 (3v3).
Motor to channel 0 and the terminal block to 5v power source.
USB port connected to an HUB with keyboard and mouse.
Ethernet Cable, and inthe power supply port I connected the 5v 2A power SUpply.

The extrange thing is that when I conect the driver, voltace in Vcc drops to 2.5 V but the firt time I connected LED was on, the problem was when I tried to program it that nothing worked (No motor No LED)

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jofegibo
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by jofegibo »

Image

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adafruit_support_bill
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by adafruit_support_bill »

What is the voltage on the VCC pin? The led is driven directly by the VCC pin, so it should light up if you have 3.3v there.
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jofegibo
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by jofegibo »

Vcc Drops down to 2.5v when I connect the driver But it's supposed to be 3.3v

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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by adafruit_support_bill »

Vcc Drops down to 2.5v when I connect the driver But it's supposed to be 3.3v
Does unplugging the servo make any difference in the measured voltage?

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jofegibo
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by jofegibo »

when evererything is disconnected, Beaglebone is 3.3V (In Vcc port)
When I connect only the driver, Vcc is 1.9V
But the servo doesn't make any difference to Vcc.

How Can I get Vcc to stay in 3.3V? Do I have to connect another power source with 3.3V to Vcc, or some circuit to do it with the beaglebone?

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adafruit_support_bill
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by adafruit_support_bill »

Not sure what the Beagle Bone can supply on the 3.3v pin, but it should be enough to drive the PWM chip. If the voltage is sagging, you either have a short circuit somewhere, or the Beagle Bone 3.3v regulator is not working right.

Can you measure the current that is being drawn from the 3.3v pin? http://learn.adafruit.com/multimeters/current

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jofegibo
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by jofegibo »

I Measured the current with two different multimeters and it got 0Amps, there was no current.

then I measured the voltage disconnecting everthing but the power suply and th driver (No HUB, No HDMI, no Ethernet)
and it's till 1.9V untill I disconnect the driver that it returns to 3.3V
the same Happens with the other driver I have, (I bought 2 of them)

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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by adafruit_support_bill »

Very strange. I would think that the BBB could supply a reasonable amount of 3.3v current.

Do you have a LED handy? Hook just the led up to the 3.3v pin in series with a 220 ohm resistor and see if it lights up.

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jofegibo
 
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Re: Adafruit 16-Channel 12-bit PWM/Servo Driver

Post by jofegibo »

It worket fine, but it was 0.033V in the resistor and 1.677 in the red LED, Voltage droped.

It's very very strange.

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