I apologize for the lengthy post, but it's been a long and frustrating journey. Thankfully, there is a happy ending, along with a video for you to enjoy. Grab some popcorn!
This post focuses on robot building, primarily electrical wiring, rather than Synthiam ARC itself. ARC is the robust platform integrated into my robot that facilitates all the magic. However, if there is an electrical issue preventing the robot from functioning properly, ARC's capabilities are limited. Regardless of whether you're working on a complex robot or a simple one, the fundamentals of wiring and powering up are consistent. These include ensuring a safe and adequate power source, using appropriately sized wiring and fuses, and designing clean, efficient wiring circuits. As I've discovered, the more complex a robot becomes, the more challenging it is to maintain clean wiring and diagnose issues.
I recently spent over a month identifying and resolving a wiring problem that arose from upgrades I made to my complex robot. It was a frustrating issue that made my robot appear broken. The problem involved a large chest neon light on my robot that flashes words in sync with sound files. When the robot is silent, the neon should be off. However, the issue manifested when the robot was not speaking, causing the neon to glow and flash on its own.
Previously, this functioned correctly for years, only flashing when a sound file played. But after I made additions and updates to some devices and wiring on the robot, the issue emerged. Initially, I suspected a ground loop was causing stray voltage to infiltrate the neon interface board, triggering the glow. My robot was built using several 120VAC to 12VDC power converters. Intentionally, I had tied the converters' AC-side earth grounds to the DC-negative output of all the converters, which has certain benefits. However, this configuration also makes creating and ground loops easier and finding them harder. My major troubleshooting step (assuming it was a ground loop issue) involved thoroughly reviewing the robot's wiring and isolating any bridges between the AC-side earth grounds and the DC-negative output wiring that powered my devices and lights. I found several of these connections.
While I believe this was a crucial step in properly and safely wiring my robot, it didn't resolve the issue. The glow and flashing of the neon persisted, leading to weeks more of testing and frustration.
To summarize (belatedly), after further testing and observations, I realized the neon's glowing and flashing issue ceased when I disconnected all grounds to the torso's micro switches. These switches are located in the torso and monitor button presses and part movements. In an oversight, I had wired the neutrals of the neon system to the same wiring block as the switch grounds. The torso switches and the neon system were then sharing the same neutral wire back to the converter that powers the neon system. I feel this was allowing stray voltage into the neon interface board and causing unintended glow.
To fix it I simply removed the two neutrals coming from the neon transformer and neon interface board from the shared switch neutral block. Then, I ran a separate neutral from these two neutral wires directly to the power converter feeding the neon system its power. Voilà! Problem solved! What a relief. Easy to fix but hard to find. LOL!
Thank you for reading!
Here's the promised video of my fix:
