Printed Circuit Board Assembly Notes

You'll need:

If you haven't done any soldering before, find some small copper wire and practice until you can get a clean shiny joint. There are many tutorials available on the web.

Here's a general outline of the assembly process:

Flashing the firmware

Unzip the source code. Edit "config.h" and examine the stanza for CAMERA_ID=99 (the default camera settings). Select the appropriate GYRO_TWI_ADDRESS for the sensor you're using. Execute "./CC" to compile the source code and generate the hex file, using avr-gcc. Use avrdude to program the Atmega's fuses and flash memory.
The gyrocam software expects the Atmega to be running at 8Mhz using the internal oscillator, so be sure to set LFUSE=0xE2.
I'd also recommend enabling brownout voltage detection, by setting EFUSE=0x04.

Debugging

The port marked "TTY" brings out the Atmega's TX, RX, and GND pins.

The gyrocam software accepts debugging commands at 9600 baud on this port to allow testing of the led, battery, servo, gyros, and accelerometers (if present). You'll have to look at the source code for details.

Cautions

The header pins for the serial port and external battery charger will accept standard hobby servo connectors. However they are not "keyed" to prevent accidentally plugging in the connector backwards. Be careful.

Also, I discovered too late that the header pins for my battery connector and charger port don't follow the defacto industry standard "JST/XH balancer plug" pin order, sorry. You'll have to modify your battery and charger connectors to match. Look carefully at the schematic.

Finally, a note on batteries. LIPO batteries must not be over-discharged. Doing so will ruin them and, worse, risk a fire if you attempt to recharge them afterwards. The gyrocam software monitors battery voltage and starts blinking the LED when the battery has about 30% capacity remaining. However there is no provision for automatically shutting the battery off to prevent over-discharge . So you'll need to remember to keep the battery charged and to turn the switch off when the gyrocam is not in use.


These notes refer to my original printed circuit board, but mostly apply to my redesigned board too.


Last updated 26 Mar 2013