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PCB's Assemble!

A project log for RGB LCD Backpack Addon

Additional IIC backpack for the IIC LCD backpack

smartroadsmartroad 09/13/2019 at 21:450 Comments

The prototype PCBs turned up this week and I have been having fun getting then working. I am still reasonably new to soldering SMT but flux is my friend! Even so, I was still having problems reprogramming the ATMEGA on my board. Turned out there was a minuscule solder jump between the SPI clock pin and the adjacent pin on the chip. Once I had that clear the chip took on the firmware with no issues.

Finally Working with wires to allow for SPI programming! And I really should clean the board better but practise...
Using my i2c scanner to find the devices on the bus
I used my i2c scanner to check the devices were communicating, 0x27 is the LCD backpack and 0x30 is my RGB backpack.
Bit of a bodge though - the ribbon cable is a wedge to get a good connection for the LCD backpack.

There are some changes I would like to do to the PCB. As mentioned in the image above I've had to wedge the boards apart to make the LCD backpack work. I de-soldered the connector to allow my backpack to attach, but I don't think the solder has flown back down fully. Next version I will use larger holes so the connector can stay soldered.

Also my backpack doesn't lay flat as I have used through hole parts for the resistor and capacitor. The resistor is the issue as it obviously comes through. I have two thoughts on this. The obvious is to go over to surface mount components. The second is to solder the top side so the excess legs can be cut flush.

To finish off this log; another video demo!

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