Daily dabbling

Raspberry Pi I2C dual motor driver

My Raspberry Pi dual motor driver has evolved quite a bit since I last wrote about it. In the original incarnation, I had planned on using the PWM capability straight from the Raspberry Pi to drive the TB6621FNG motor driver. That didn’t work so well due to the fact that […]

Raspberry Pi dual motor driver

This is only sort of a new design. I’ve used this TB6621FNG dual motor driver chip on a number of my boards prior to this one. I basically just took one of my existing boards and shuffled things around a bit to fit the Raspberry Pi Zero form factor. In […]

Final Pi Zero LiPoly mod

I solved the final issue with my LiPoly board. It was a minor one. The yellow LED is supposed to indicate whether the LiPoly battery is on or off. It was always on. In a Captain Obvious moment, I discovered that it was always on, because I told it to. […]

Raspberry Pi Zero stack-up

Not stack-up, as in PC board layer stack-up, but add-on board stack-up… The LiPoly board is working fine, as detailed in my prior posts. The USB hub board is also working. The stack shown here has the Pi Zero and both boards. As shown the D+ and D- lines from […]

Raspberry Pi UPS

I built up two more of my Raspberry Pi LiPoly battery back up boards today. After doing so, it occurred to me that, in addition to allowing for portable use of a Raspberry Pi Zero, as I had originally intended, the board, with a few minor modifications, will work quite […]

Pi with my LiPoly board

Pi Zero LiPoly – Final

My Pi Zero LiPoly board was working, but not exactly in the way it’s supposed to. Charging was fine. Powering the Pi from the battery, fine. Th problem came on the net MCP_IN, in the schematic below. I was reading voltage at the test point for MCP_IN, JP4. Either the […]

Pi Zero USB hub

Pi Zero USB

I’m far from the first person to put together a Pi Zero USB hub. In fact, mine is loosely based on the open source design from @richardhawtorn, which was based on the design by @MakerBro. The key difference is that I removed one of the USB A ports in exchange […]

Pi with Zero charger

Pi LiPoly charger on Pi day

I considerably reworked the design, and now have one of those boards built up.. I put a P channel MOSFET on the power line going into the MCP73831 LiPoly charger chip, which is the Pi 5 volt line. The power line out, has a Schottky diode, and then goes to […]

Raspberry Pi Zero

Pi Zero In Hand

I own a decent variety of Raspberry Pi models. I’ve got an old B, a Pi 2, an A+, and my Zero came in the mail today. Unfortunately, I wasn’t able to buy the $5.00 version, but had to buy it in a combo pack from Adafruit. I got the […]