One leg shifting off-center on powerup

Posts: 1
Joined: Sun Oct 15, 2017 8:43 pm

One leg shifting off-center on powerup

Postby TheGreatAndPowerful » Wed Oct 25, 2017 10:02 pm

I actually have a few problems at the moment:

1) When I turn on the mePed, the front left leg, immediately moves from the 90 degree position back about 15 degrees. As I have it walk forward, it continues to move further and further back until it gets bound up with the left rear leg. I don't really know how to approach diagnosing the error to even tell if it is hardware or software. I suppose I could switch that leg with another to see if the problem stays with the leg. My initial assumption is that the servo motor doesn't know where it's center position is located.

2) I find that even if I direct it so go back, left or right, it only wants to move forward. I can get it to dance (8) and wave(2) and when I choose a new command, it repeats the last command at least once but even trying to go back, if it was going forward, it just continues to do so.

3) Are the eyes (ultrasonic sensors) active? I thought that the would keep the mePed from running into a wall or other object but it does not. I have been going throught the code from the website trying to learn and to see if that is functional or not.

4) You had mentioned, and I see the connector, that there is an option for a bluetooth receiver on your custom board. I was wondering if you recommended a sensor for that position. I work with some iOS and Android developers and they could help me right an app to use that I believe.

Thanks for your help

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Posts: 37
Joined: Thu Sep 29, 2016 6:43 pm

Re: One leg shifting off-center on powerup

Postby spierce » Tue Dec 11, 2018 7:22 pm

Hello, thank you for your post. I'm sorry you're having some issues with your mePed!

1) It sounds like the servo isn't working properly. Upon turning the mePed on, all servos should move to their center (90°) position and stay there until you command the mePed to move. Some movements such as dancing, waving, and bowing will return the servos back to center but walking motions will leave the servos in their last position after the movement so they are ready for the next movement. Since the servo is moving farther and farther back until it binds up, it sounds like it's not working properly. Please email you name and address to and I'll send you a replacement servo to fix this issue.

2) It's important to point the IR Remote down towards the IR Sensor on the mePed. If there isn't a direct line of site between the IR Remote and the IR Sensor, the commands won't be sent correctly. When the mePed sees a command it doesn't understand, it will repeat the last understood command, which is what you're experiencing. Also, if you try to use the mePed in direct sunlight or other lighting that outputs a lot of IR light, it can interfere with the IR Sensor.

3) By default, the Ultrasonic Sensor isn't activated but there is a function called get_distance that when called, it will use the Ultrasonic Sensors to calculate the distance the mePed is from an object. You can modify the sample program to check the distance from an object and prevent it from moving forward if it's too close.

4) The recommended Bluetooth module is the HC-06. It can be found on our website here: ... dule-hc-06

If you need anything else, please feel free to post a reply or contact me via email

Thanks again,
Scott Pierce

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