This article is part of a series.
- Part 1 - The Hunter S. Thompson Board -- Arduino Mega Mini
- Part 2 - My Eagle PCB Walkthrough
- Part 3 - Mega Mini Motor Shield (M^3)
- Part 4 - My Eagle PCB Walkthrough
- Part 5 - Populating and Programming and APM
- Part 6 - Arduino to RPi -- Galvanically Isolated I2C
- Part 7 - Incomplete Works
- Part 8 - HM-10
- Part 9 - Jot
- Part 10 - Homemade Pulse Sensor
- Part 11 - ATtiny Adventure -- I2C on ATtiny 84/85
- Part 12 - ATtiny Bitsy Spider
- Part 13 - This Article
- Part 14 - Scarab
- Part 15 - The Valdez Mutant -- LPC1114 QFN
- Part 16 - Lab Controller PCB
- Part 17 - Lab Controller v05-09
- Part 18 - Robber Board
Originally posted on www.letsmakerobots.com
Awhile back Sparkfun posted a new product, their MiniMoto breakout board. It breaks out the DRV8830 IC, which is a serially controlled (I2C) H-Bridge. I thought the chip was nifty. A few problems though,
- Sparkfun’s breakout was 25x25mm for one bridge. If I added another and then an Arduino Pro Mini it’d lose smallness.
- It’s $9.95
- It’s not on a purple board :)
So, I set out to make a robot controller with it that was smaller than a Sparkfun breakout. What I ended up with is a little bitch I refer to a Kobold.
The board is pretty straightforward. It has an ATtiny 85 that acts as an I2C Master using the SoftI2CMaster library. This allows the Tiny 85 to control two motors using only two pins, leaving three for your pleasure.
My end goal will be to build a shield for it and hook up a HM-10 to make it a little wireless tethered bot. This would bring me down to one pin, which I’m sure will be some sort of range finder or feeling sensor.
- 1 x ATtiny 85 SOIC $1.21
- 2 x DRV8830 MSOP-10 $5.10
- 2 x .33 Ohm 0402 $.86
- 1 x 1uF 0402
- 2 x 4.7k Res. 0402
- 1 x Kobold PCB $2.50 (for three)
The board can be programmed with an Arduino ISP:
Now, I just need to make a robot with it :)
I’m currently working on a second iteration to correct some problems. I’ll also add a few features, like my pogo-pin programming interface. The shield I have designed for it will also include a charging circuit and probably a SMD step-up circuit that should convert a LiPo to a nice 5v.
Anyway, work in progress…just thought I’d share.
If anyone is interested in this board, please wait a few iterations. I get worried I’m making blue-smoke with someone else’s money. :)
Here is the code running in the video: