This is a Low Voltage, 2A motor controller BoosterPack for the Ti LaunchPad. So far I have not found a motor controller yet so I decided to make one. This is the first in many BoosterPacks I will be designing and selling. It uses the Ti DRV8833PWPR Dual H-bridge Motor Driver chip. The chip is capable of 2Amps per motor channel and a motor voltage from 2.7V to 10.8V. Logic voltage for the DRV8833 is 3.3V which makes it a perfect match for the MSP-430 LaunchPad.
The BoosterPack has the nSleep pin broken out from the DRV8833. Using this pin will put the DRV8833 to sleep to minimize current draw. If this pin is not needed or the LaunchPad is lacking I/O there is a jumper to pull the nSleep pin high.
This circuit is designed around the MCP73837 chip. There are a couple different versions of this chip which allows the same PCB have a charge cut off voltage of 4.2V for normal lithium batteries and 4.35V for high capacity lithium batteries.
4.20V – MCP73837-NVI/UN
4.35V – MCP73837-FCI/UN
It charges via USB at a rate of 500mA or an external power supply rated at 5-6V at 1A. I would use a power supply at a rating of at least 1.2A for this charger.
Added a micro usb plug to compliment the mini usb plug and DC power jack. Made all the passive parts 0805 size to make the board easier to assemble. Tweaked the mounting holes a bit as well.
I picked up some of these really neat VFD alphanumeric displays at a surplus shop while at Maker Faire. After acquiring the datasheet from the manufacture, I decided to test them with the built in test mode. I have already started writing the code to run the display and will be posting the code and datasheet when it is done.
Here is a status update for the NES Top Loader portable!
Assembling the front half of the case. Using size M2 sheet metal screws to attach the PCBs to the case. Holes are tapped with a 1.5mm drill bit before hand. For those that know the PSone screen accepts 7.4V then converts it down to 5V in some areas with a 7805 linear regulator. I removed the 7805s and attached my 5V switching power supply to the pads which dropped the power draw of the screen.
The back side houses much more parts. Batteries, switching powersupply, NES Top Loader PCB, speaker, amplifier, and volume control are all housed here. There is no hotglue in this portable. Everything is mechanically held in place. Some electrical tape is used to insulate parts but that is about it.
So I just finished building my first Super Boost. It converts 2.2V – 4.5V to a steady 5V source. This is perfect for charging a cell phone or any other device that charges via USB by using 2 AA batteries or a single cell lithium battery.
The project page is here and the DIY page on assembly is here.
So this is meant to be paired with a UART program. This code is not all my own but I could not remember where I found it. I have edited the original quite a bit but the same structure is still there. If someone recognizes it please let me know so I can give credit.
The case I designed and Chris printed showed up today. This is the prototype case. I had to make some slight tweaks to the design to get it ready for the final version.
You can download the files on the NES Toploader project page and check out the progress of the portable.
