One of the PCBs I designed for the BBC micro:bit arrived and I wanted to see if it worked, so here is a short blog about it.
This PCB is one of the two PCBs that will make up the micro:bit TXTR introduced in Blog 3.
Here is what the PCB looks like on both sides:
This PCB primarily connects the micro:bit to an SPI 5110 LCD, but it also has connections for external power, I2C, 3 analog inputs, and an SPI QWERTY keyboard. It includes a power switch and a backlight switch for the LCD. There is a footprint for a FRAM chip to augment the memory in the micro:bit, since LCD graphics and fonts will require more than what is available in the stock micro:bit.
Here is what the initial build looks like - the micro:bit is located beside the LCD, leaving room for the keyboard below:
Here is a short video of the micro:bit and LCD in action:
This is a nice milestone - the first circuitry and micro:bit software for the final design that is actually working.
The software is going to change significantly because right now the LCD font takes up most of the memory. This will be off-loaded either to the keyboard module (PSoC4) or the FRAM chip, hopefully leaving sufficient room for Bluetooth communications software.
Here is an illustration of what the micro:bit TXTR will look like, in case you missed Blog 3. The area between the displays and the keyboard will be occupied by the keyboard microcontroller (a PSoC 4). In the final design this area is minimized by overlapping the two circuit boards:
The keyboard PCB was manufactured about a month ago but is still making its way around the globe. Hopefully it gets here soon as I want to see the whole device working.
Other aspects of the project are undergoing quite a struggle. The deeper I get into the PSoC6, the more I need to learn. I'm still doing a lot of wheel spinning and head scratching, but there is minor progress - very minor.
Upcoming blogs:
- how Stirling engines work
- start connecting some sensors to the PSoC6
- designing the sensor interface PCB
- the micro:bit keyboard
Related Links:
Bluetooth Unleashed Design Challenge
Bluetooth Unleashed Design Challenge: The Challengers
Bluetooth Unleashed Design Challenge: About This Challenge
Links to other blogs for this project:
Stirling Blue - Project Description - Blog 1
Stirling Blue - Unboxing Hero - Blog 2
Stirling Blue - micro:bit TXTR - Blog 3
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