Last night I conected servo to wrong P702 pins and broke my Raspi.
Now I got a new Raspi and connected again with correct pins.
I could launch simple_navigation and connect with Robot_Commander, I could launch rviz and see the picture.
But when sending command to Robot, it didn’t move.
roslaunch magni_demos simple_navigation.launch
I noticed below errors in logs:
I take off the servo wires from P702 pins, then the robot could move. Thank god the MCB is not broken.
Could you please help me why this happen? Anything I need to do to use those pin on sonar board? Could this because the sonar board is broken? Thank you!
I used below pins for 3 servos:
servo #1:
Pin 4 for power
Pin 6 for ground
Pin 7 for PWM
servo #2:
Pin 2 for power
Pin 9 for ground
Pin 11 for PWM
servo #3:
Pin 1 for power
Pin 14 for ground
Pin 12 for PWM
I will inspect your picture next but I want to let you know we have just greatly improved explaining how users can use GPIO pins that we are not using OR how users without a Sonar board can disable the sonar board and then have many lines they can use.
I next would like to say that ribbon cables and connectors are very very easy to get mixed up in using. My #1 advice for any project where custom ribbon cables is used is to shutdown the magni and disconnect the main battery cable. Only then plug in your custom ribbon cable and use a continuity meter (or a meter with a ‘buzz’ feature) to verify that the ground pins you think should be present on the other side of the ribbon cable are in fact EXACTLY where you expect. Besides pin 1 on the wrong end (almost always a disaster) It is also very common that the even pins get swapped for the odd pins and this too is a disaster. The 50-pin connector must be treated very carefully because it exposes directly raspberry Pi power pin for 3.3V and ALL GPIO and other pins.
The most common failures we see to the Raspberry Pi are the destruction of the raspberry Pi 3.3V power and the destruction of the serial transmit or receiver drivers on the MCB.
Our next version board does things to limit the above two issues but that does not help you right now so sorry about that.
Next I want to point to another very good page on our Learn pages that shows in detail the 50-pin ribbon cable and proper connection. This also was updated maybe 3 or 4 weeks ago and for your case I strongly suggest you also refer to this page: https://learn.ubiquityrobotics.com/camera_sensors
Thank you @mjstn2011 a lot!I’ll be careful on that.
I do checked the articles you mentioned and also checked the Magni_MCB_Pinout.pdf, there was description of that the first 40 pins of 50 pins are same as Raspi GPIO.But I’m still not clear on which side of the sonar board 50pins is the first 40 pins.Could you please Help to inspect the pictures I attached and let me exactly which is the pin 1 which is pin 2.Appreciate for that!
Pin one on P702 is to the left and on the lower row of pins as you look at the Magni from the front.
One of the things we are doing on rev 5.2 MCB is having a larger white dot that is not under the connector. You can see pin 1 on P702 will be the only pin with a square pad on pin 1 hole.
Even if you look at all the pins and so on please please get a meter that will buzz when you touch the probes together and make sure the pins you think are ground get connected by testing with the buzz.
Unless you are extremely familiear with dual row ribbon cable connectors it is very very easy to make a mistake because P701 has no ‘key’ because it is an odd 20mm high dual row connector it is designed to have the raspberry Pi plug in and does not have a key to ensure proper ribbon cable use on that end.
Also the rev 5.2 boards will have extra electronic circuit breaker to protect the high current battery connection going in the P702 connector at 24V as another improvement.
I am telling you these improvements so you realize we are always trying to learn from field problems and make improvements so future product shipments are better.
I try running roslaunch magni_demos simple_navigation.launch but it kept doing what the image shows for several hours. Does anyone know what might be the problem?
