Eldricht (named after a monster in Zork) will be used demonstrate my pcb design skills and learn more about closed-loop control systems. It will have the ability to collect inputs from its 5 QRE1113 line sensors, and a single infrared receiving sensor. The little bot will be capable of following a standard chisel dry erase marker and take commands from a TV remote.
I started this project after being impressed with the capabilities of the m3pi robot (by Pololu) and the work of shlonkin and his tiny robot project. I figured "How hard could a cheap line bot be?"
- Line tracking
- IR remote communication.
- Tiny footprint and price.
- Use of Common ATMEGA 328p-32pin (Arduino compatible)
- Build DIP prototype (abbreviated)
- Draw schematic.
- Design PCB
- Send to PCB fab (OSH Park)
- Solder Components.
- Add bodge wires.
- Upload test code.
- Select Battery and Charging system.
- Test for fabrication issues.
- Begin programming control system.
Version 0.9 of Eldricht. Data sheets and logos included.
Zip Archive -
6.63 MB -
01/25/2017 at 04:21
Atmel Microcontroller (32-TQFP)
Sensors / Angle, Position
H-bridge DC motor driver at 850mA (SOP-8)
10k Ohm Resistor
100 Ohm Reisitor
View all 11 components
02/10/2017 at 17:41 •
V0.9 Has arrived! Apart from adding a cool new logo I have corrected the SCLK problem with V0.8. The only bummer is I am out of ATMEGA 328p-au's and will need to wait for new chips to arrive.
In other news I selected the motors for the project. The 60 rpm 2.4-6.0v reduced motor supplied by Seeed Studio will be more than enough to push the little bot along (cheaper alternatives are available elsewhere but Seeed is a more stable supplier.)
I also selected a battery. Something similar to this E-Flite 200 mAh 3c 3.7v should be good enough for the prototyping phase. I have been looking into on board charging and 5.0v batteries with more mAh but for now this tiny battery will have to do!
12/30/2016 at 20:58 •
Good news everyone! I received the boards from OSH park! I soldered on some components and tested the ATMEGA 328P-AU. I currently am running a blink at 1Hz using Atmel Studio. Seriously considering adding debug wire...
I have found the following design problems:
- Serial Clock for the 328p is abreviated SCK not SCL - I assigned it to the incorrect pin.
- 328p Pin 1 marker not visible on silkscreen.
- Outline is not symmetrical.
- Trace from Pin 1 to Left H-Bridge crooked.
12/27/2016 at 03:26 •
The first three boards are almost here! I finally got around to ordering the 0603 capacitors and motors. I won't add the motors to the component list till I'm sure the robot will be stable. I selected a 3.7v Li-Po with 680 mAh, however I will be running v0.8 tests directly with my bench supply until I have completed debugging the board. Let the wire-bodging begin! I am sure the 328p will tap out after few minutes on that battery anyway. Unfortunately that is the way things are going to be till I find a cheaper and less power hungry micro-controller.
I also added the RST1 button and S1-S5 3d files to the KiCad model. It was a real pain to get the model placed directly on the pad. Thank you eazyw for kicad stepup! It made going from Rhinoceros 4.0 to FreeCad to KiCad a little easier.
12/14/2016 at 04:47 •
My AVR Dragon's usb drivers were on the fritz! It took half the day just to get my laptop (a Dell abacus from 2007) to get it to recogize the Dragon. Ugh. I installed AVR Studio 6.2 inorder to get the sick dragon pup to work. I updated the firmware and now it is ready to flash to Eldricht when the PCB's arrive. Guess this is what I get for keeping it in storage this long. :)
View all 4 project logs
Enjoy this project?