Soldering the Sensor Board

See the Mounting page for where each part goes.

Warning: The pictures below show the 0.21 board, not the most recent 0.22 version!

Blank Boards

Populating

Start from the center with small parts, and work outwards, repeat for larger parts. Make sure not to block access to solder pads with other parts. (This assumes you are comfortable soldering small smd-parts and don't need practise.)

1. Start with U5 (AD7924), U13 (ADS1255), U14 (MAX3002)

2. U11 (ATmega328p), U6 (LT1763-5), U4 (OPA4350), D2 (LM235DT), U9 (OPA2350), U10 (LT1763-5)

3. all 0805 and similar parts. Don't solder C44 yet, its hard to reach the pins of the baro afterwards.

Attention! The following image has C12 and C13 mounted wrong (rotated by 90 degrees). See image in step 5 for correct position.

4. large smd caps

Attention! The following image has C12 and C13 mounted wrong (rotated by 90 degrees). See image in step 5 for correct position.

5. non-smd (through-hole) stuff (connectors)

C12 and C13 are correct in this image.

6. The breakout for the LIS3LV02DQ ACCelerometer has to be mounted lying parallel to the SB.

Important note: Contrary to what the picture shows, you must secure the ACC board to the SB so that it can't vibrate on its own. If you don't do that, the NG is likely to crash due to bad sensory input! To secure it, note the two larger holes at the corners of the ACC board. There are two matching ones on the SB board. Connect them, e.g. using a spacer, so that the board is fixed.

7. The breakouts for the Roll and Pitch/Nick Gyros have to be mounted standing on one edge, with the +5v, gnd, rate, vref, temp, test and err signal. The other signals are not used on these two sensors.

8. If you want to mount the compass module (not shown in the picture): The direction of the arrow on the compass board points towards the fat side, where the yaw gyro sits.

To mount the tantals or to check mounted ones do the following. Every tantal has a thin line on one side. For tantal ist the other way around than for other elkos: The line is "+" and the opposite is "-". To check if it's correct mounted you can use your circuit indicator as shown on the picture.

"-" and the not-marked-side of the tantal should have a connection.

HIGH resolution images

click on the images below to get high resolution images ( large, 4MB each)

Testing

After soldering, you should check neighboring pins of the smaller ICs for shortcuts. Just test each pin with its immediate neighbor to see if you have a shortcut. Note that some have capacitors behind them, making them shortcut for a short while (less than a 10th of a second, usually) - that's nothing to worry about.

Here's a list of ICs and what you should find in your tests:

• U3 (Gyro): Shortcut between 6-8
• U4 (OPA4350): Shortcut between 1-2 and 6-7 and 8-9 and 13-14
• U5 (AD7924): Shortcut between 5-6 and 4-8-13-16
• U6 (LT1763): Shortcuts between 1-2 and 3-6-7 and 5-8
• U9 (OPA4350): Shortcut between 1-2 and 6-7
• U10 (LT1763): Shortcuts between 1-2 and 3-6-7 and 5-8
• U11 (Atmel328): Shortcuts between 3-5-21 and 4-6-18-20
• U13 (ADS1255): Shortcuts between 2-3-5-11 and between 8-9-10.
• U14 (MAX3002): Shortcuts between 2-10-19
• U15 (baro): No shortcuts

If you want to test the SB separate from your flight control, check that you have no shortcuts between the power-planes for GND, 3.3V, 5V and 12V. Then you can powerup the SB, the pinout of the X-PS connector is:

On the SB, only GND and 12V of the X-PS are used.