Debugging
'Stuttering' power
Sometimes the robot ‘stutters’ when turning on the power switch. What is happening is: the electronics are being powered, there’s a spike in current draw due to all the peripherals being powered up at the same time, the boost convertor and batteries are trying to handle this spike. Sometimes the boost convertor and the batteries are unable to handle it, which causes a ‘brownout’ from the dip in voltage, where some of the peripherals and microcontroller are no longer powered. Once the batteries and boost convertor ‘recover’ and the voltage rises again, the process repeats itself as more peripherals start again, causing a brief spike in current.
Some AA batteries will be better at handling this than others due to their internal resistance, which enables them to output current at a faster (or slower) rate. The batteries in the kit are alkaline AA batteries. The batteries we use for our own robots are rechargeable Li-Ion AA batteries. We have found that moving the wings to the upright position before powering on does help. As well, if the AA batteries are running low on power, it can make this stuttering issue more likely to happen.
Solution:
Switch to supply power to the robot via the USB-C port. Check and replace AA batteries.Alternatively, this can be due to Boostlet! becoming unseated in Chonky’s headers. For example, if you happened to drop the robot. (We know this from experience!)
Solution:
Ensure Boostlet! is pressed in to the headers completely.Power switch ruined / not assembled properly
The plastic shroud of the power switch is quite sensitive to heat when soldering. Sometimes this can lead to irreversible damage of the switch.
Solution:
Contact us for a replacement via Discord. In the meantime, proceed through assembly without the power switch. When it is time to test, first: ensure no power is connected - no USB and no batteries. Second: connect the two headers on Chonky for the power switch together. This could be done with a spare piece of wire, or it could be done permanently by bridging them with solder. When implementing this fix, the robot will always be powered on if batteries are installed. To power off the robot, batteries will need to be removed each time. (But at least it would work!)Cables interfering with lid
When the cables are situated on top of Chonky, it can make the lid difficult to fasten down seamlessly.
Solution:
Push the wires through the side slot of Chonky and push them downwards, one cable at a time. It helps to do this before the Chonky circuit board is fastened to the enclosure. Using tweezers (preferably, ESD safe) can help with this task. With a headlamp (or bright light), it can be possible to see some of the cables underneath through the battery bracket. If so, gently pulling the cables downwards can also help. This task requires patience! You will get it.Battery cover falls off
The 3D printed piece that covers the battery compartment is a simple friction fit and can vary slightly in its dimensions due to humidity, material, and manufacturing tolerances.
Solution:
Add a dab of hot glue to the side of the battery compartment. Once the hot glue has cooled enough to touch, smooth it down with your finger. It should be thin enough to provide a bit extra ‘grab’ when attaching to the enclosure. If too thick, refine with an xacto knife. Repeat these steps until the fit is good!Servo horn fastening to 3D printed piece not secure
The servo horn step involves chamfering two of the holes. Sometimes, if the chamfer is too large, it interferes with the wood screw’s wide thread’s ability to grab into the plastic of the servo horn.
Solution:
Using the holes for positioning reference, apply hot glue to the servo horn and press onto the 3D printed piece. Once the hot glue has become tacky, apply more ot glue on the other side of the servo horn to make it more secure. Add some more hot glue that envelopes the servo horn onto the 3D printed piece, making sure that the axel hole remains clear.Servo horns positioning up / down not symmetrical
Sometimes the splines on the two servos do not entirely match up. For example, the one on the left could be slightly different than the one on the right. The easy solution is to get it to be the best possible positioning, and then move on to the next step. The more complex solution is to adjust the position value in the firmware.
Solution:
Adjust either theSERVO_LEFT_UP or SERVO_RIGHT_UP value in the Boards.h file of the firmware. Try incrementing or decrementing by 50. Repeat this process until the result is tuned to your liking.
Servo making ‘growling’ sound
The servo motors can emit a sound akin to ‘growling’ when they are stalled. Stalling means the servo’s torque is overcome by an applied force to the servo arm. For Robot Butterfly, this can be caused when the servo arm collides with the Neopixel bracket when in the up position, or when the servo arm collides with the lid in the down position. While the servo motor itself can survive this for small amounts of time, it is not beneficial to its long term use to stall the motor for long durations.
Solution:
Remove the axel screw from the servo motor. Adjust the positioning of the servo horn on the servo motor’s splines. Validate there are no collisions by checking the robot’s wings in the up and down position.What do the LEDs mean
There are a few LEDs that are visible through the LED ports on the back of the enclosure.
On Chonky, there are two yellow 5 mm LEDs. On the left hand side, is D2. In the firmware, D2 is LED_COMMS_PIN (pin 5). On the right hand side, this is D1. In the firmware, D1 is LED_HEARTBEAT_PIN (pin 13).
LEDs from Keystone are also visible through the LED ports on the back side of the enclosure. As well, sometimes their brightness reflects in Chonky’s 5 mm LEDs. On the left hand side is power. The power LED is on all the time. On the right hand side are TX and RX. The TX and RX LEDs are activated whenever there is data on the serial port. This can be useful for a visual check, but it also just looks techno cool.
Technical support
Have you run in to an issue that is not captured here? Sorry for the road bump! We’re here to help! Presently our technical support is solely through our Discord server. This is because it helps share the problem at hand with multiple people, which could lead to a solution faster with the community chiming in their solutions. As well, it opens the possibility of assisting via voice channel too. Joining and getting started with Discord is a straightforward process that will only take a few moments.
Solution:
Join our Discord server! The link is provided inside the Robot Butterfly box and in the email receipt from our store.Page last updated: January 22 2025 17:23:03.