2016 Hardware Updates

raspberry-pi   raspberry-pi-zero   gps   accelerometer   i2c   uart  

Left: 2016 version mockup (so much room for activities!), Right: 2015 version.

I finally gathered up some of the more elusive parts, so it's time to start assembling the 2016 version of the Mr. Gibbs hardware.

The first change is the power supply. Rather than the 5000mah usb battery pack, I have decided to power the system via 2 18650 cells, holder and a switching voltage regulator. I haven't tested this yet, but in theory it's still about 5000mah. Unless the regulator is horribly inefficient this should be more than ample capacity. I also plan to add in both a switch to turn it on/off, and a charging jack. The reason for this change is simply to shrink the battery a little bit. Cost-wise it is actually about the same until I can find an inexpensive source of good 18650s (quality seems to vary significantly).

Next, I'm going to use a pi zero rather than the pi 2. There are 2 reasons for this change. First, cost. The Pi Zero is $5, the Pi 2 is $30. While the Pi 2 is great for development, all the power, ports, and size are unnecessary on the boat. Second, size. The Pi Zero is physically about half the size of the Pi 2. I soldered a full sized usb port to the bottom of the Pi Zero and the Bluetooth adapter will be connected there. The CHIP should arrive in June so it's not going to make it for the early part of the season.

For the sensor board, there are a couple changes. First, I'm going to change the form factor from a board connected via ribbon, and instead build a "hat" for the Pi which will simply push on to the 40 pin connector. Second, I'm going to have a prototype PCB printed rather than doing the clunky wirewrap/solder route I went last year. The cost of custom PCBs is so low now there's no reason not to. Finally, I'm going to move from an MPU-6050(accel+gyro) + HMC5883L(magnetometer) to an MPU-9250 which combines all 3 into one breakout. I'm also considering adding a SSD1306 Screen as a status/system display.


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