Customization hint for PLEN2 compatible servos to use

Guvalif · 2016-03-09 00:03:12

Hi, PLEN users!

I recieved an inquiry that how do he/she need to edit the firmware with unofficial servos.
I share you with the customization hint.

When I configure the firmware for any servo, I use the following sketch to research the PWM settings.
Please write researched PWM's range in JointController.h :)
-> https://github.com/plenproject/plen__fi … hecker.ino

If you would like to get more details, please check below.
-> http://plen.jp/playground/wiki/specific … _reference
-> https://github.com/plenproject/plen__fi … #L505-L520

Last edited by Guvalif (2016-03-09 00:10:35)

cliffkhew · 2016-03-09 04:38:59

Anybody can confirm that Emax ES08MD/ES08MD II are compatible the the servo brackets and servo horns .stl files?

jeanlouisquero · 2017-03-13 18:28:02

Hello
I use ES08MD.
Certain parts. Stl print in 3d are fragile.
It is necessary to rectify certain parts the servo having difficulty to enter its support.
The connections between the servo and its support deteriorate very rapidly. I modified the parts using the

If I understood correctly it is necessary to look for the position of the servo 0, 180 ° and rectify the pwm.

By cons all links you indicate its in 'page not found
Error 404 '
Thank you for your reply

Guvalif · 2017-03-27 09:22:48

Hi jeanlouisquero,

Just for reference, our official github account was moved once: https://plen.jp/playground/forum/viewtopic.php?id=52
Changing the word 'plenproject' into 'plenprojectcompnay', the all URL could be working now.

jeanlouisquero · 2017-03-29 17:30:33

Sorry but not better
exemple : https://github.com/plenprojectcompany/p … #L505-L520

erreur 404

Or I did not understand

Guvalif · 2017-04-07 04:57:28

Also some of the repositories were changed new name.

For instance:
x plen__control_server -> o plen-ControlServer
x plen__firmware_for_Arduino -> o plen-Firmware_Arduino

dielessen · 2017-05-14 19:24:38

How does this work? Can you be more precise please.

dielessen · 2017-05-18 13:07:01

Im trying to determine PWM_MAX and PWM_MIN for my es08MD II servo's. Plen2 is now clapping againt his belly. The arm is not getting the right angle.(Shoulder pitch) It needs to go higher, so i think i have to change the PWM values? I have really no clue wich values i have to use. Angle_MIN and Angle_MAX are set to 800. How to get the right pwm vaules ? Thank you. I do not know how to research with the pwm_checker.ino. Do i have to upload the sketch with the jointcontroller.h and system.h file and watch the serial monitor or something?

Last edited by dielessen (2017-05-18 13:11:06)

Guvalif · 2017-05-22 03:32:01

Hi dielessen,

Current actual URI is shown as below:
https://github.com/plenprojectcompany/p … wm_checker

I think you need to configure PWM width and also re-setting up positions of joints.

`pwm_checker.ino` can detect servos' PWM parameters pressing `m` or `p` key.
How to upload this is copying the files described in the `dependencies.json` to the directory, after that use Arduino IDE.
Using this sketch, you can see the servos movements and these PWM parameters on your serial terminal.

Please write down relationship between angles and PWMs in the following lines:
- https://github.com/plenprojectcompany/p … .h#L65-L67
- https://github.com/plenprojectcompany/p … #L135-L142

As set positions of joints, for instance, if you set up arm's servo being 0 degree as the center, the arm can move ±60 degree.
Being +30 degree as the center, the arm can move from +30 degree to -90 degree relatively.

Last edited by Guvalif (2017-05-22 03:33:49)

dielessen · 2017-05-22 08:30:48

Hi Guvalif, Thank you for your anwser. I will try and get back to you. Im new to the arduino stuff but im a quick learner. Im not sure if i understand the position of the joints. Are you talking about the home positions you set with the control server?

dielessen · 2017-05-30 09:40:23

Im trying to get it work... but with no success. I have uploaded the sketch. Then im making a serial connection. Im pressing "m" or "p" key all i get is: output : 528 (internal = 495) . i dont know what to do now ? When i hold the m or p key the numbers go up and down but nothing happends. Am i doing something wrong here? Please help me out.

dielessen · 2017-05-30 20:38:17

Ok i found the issue. There is only one servo output working.. the first one. I think i found the right PWM values. / range. Im not really getting the angle / pwm range . when you choose an angle of 700 it will be at max at 700 if you choose 800 it will be at max at 800. Its more like how far you think it is and choose the richt angle? Im now at 800 .. also because all motion files are 700 at max. So there is some room adjust some joints / positions

for some reason from neutral position to negative angle is always less then to the positive one. For now im just adjusting the jointcontroller.cpp angle_min / angle_max positions to get even angles on both sides. Dont know if that is the correct way?

Lots op questions . Robot is working great now .. i just want to understand and if im doing it at the right way.

Guvalif · 2017-07-28 07:09:17

Hi dielessen, sorry for delay in this reply to you X(

The firmware of PLEN2 can control a servo motor by bit-based PWM (written in JointController.cpp).
The Arduino device on PLEN2 (Atmega32u4) supports bit width as 10 bit (= 0 ~ 1023).
Thus, using the helper program, you can see a servo movement when input 10 bit value.

PWM configuration are different between one and another one, about servo motors.
For instance, connecting official servo and input 410, it moves -90.0 degree.

By the way, how can we define frame of reference on each servo motor?
I set up the axiom as wiki page right-hand: http://plen.jp/playground/wiki/specific … _reference
With a protractor, you can set up your own original servos configuration on the firmware.

Last edited by Guvalif (2017-07-28 07:09:59)

PLEN Playground - Forum

#1 2016-03-09 00:03:12

Customization hint for PLEN2 compatible servos to use

#2 2016-03-09 04:38:59

Re: Customization hint for PLEN2 compatible servos to use

#3 2017-03-13 18:28:02

Re: Customization hint for PLEN2 compatible servos to use

#4 2017-03-27 09:22:48

Re: Customization hint for PLEN2 compatible servos to use

#5 2017-03-29 17:30:33

Re: Customization hint for PLEN2 compatible servos to use

#6 2017-04-07 04:57:28

Re: Customization hint for PLEN2 compatible servos to use

#7 2017-05-14 19:24:38

Re: Customization hint for PLEN2 compatible servos to use

#8 2017-05-18 13:07:01

Re: Customization hint for PLEN2 compatible servos to use

#9 2017-05-22 03:32:01

Re: Customization hint for PLEN2 compatible servos to use

#10 2017-05-22 08:30:48

Re: Customization hint for PLEN2 compatible servos to use

#11 2017-05-30 09:40:23

Re: Customization hint for PLEN2 compatible servos to use

#12 2017-05-30 20:38:17

Re: Customization hint for PLEN2 compatible servos to use

#13 2017-07-28 07:09:17

Re: Customization hint for PLEN2 compatible servos to use

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