Month: April 2015
Toybrain Returns Again
I found a motor driver chip that looks promising. It does not support easy (solderless) swapping of the motor drivers, but I’ve also had a bit of a shift in my use case. I’m still looking to lobotomise and re-animate children’s toys, but I’m doing it for swarm robotics on the cheap, so being small outweighs replacing the motor driver chips.
The IC is the TI DRV8830. It is a 1A single-channel MOSFET H-bridge with an I2C interface and automatic current limiting. The automatic current limiting makes it very hard to blow the driver by overloading it, so I don’t have to worry about replacing the drivers as much.
Giving up on the Shark Joystick
I’m going to hang on to the parts, but instead of reverse engineering the joystick control scheme for my Dynamic Controls Shark joystick, I’m going to replace the motor driver and everything related to it.
The main reason to give up on this is that it’s not the project I’m doing. The project is “build a mobility platform for fire art” not “reverse engineer a joystick”. Hacking the joystick would have helped with the real project, but it’s also a time sink. For $60, I can get a “100A” motor driver from China. It’s probably not good for 100A, but it will probably work well enough to let me get on with the rest of the project.
I had hoped that the existing motor driver was able to be easily converted to use my own control IC, but it has a very-fine-pitch surface mount part that appears to be custom silicon, so I can’t easily drop in a programmable replacement. THe custom chip is probably partly to blame for why I couldn’t interface to it, since only Dynamic Controls knows how they implemented the UART. I did figure out where the H-bridge drive lines were, so if I felt like it, I could probably drive it, but the difficulty would probably be on par with making my own driver, and the results would be messier.
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