PCBs are here!

A project log for Tangible programming

An Arduino-based tangible programming effort

AmosAmos 01/24/2019 at 01:573 Comments

My first JLCPCB order arrived yesterday - I am so excited! 8^)

I will be soldering some of these up later today...

I also have a pogo-pin programmer so I can re-program the Arduino Minis in place without needing the 6-pin headers soldered on. (I messed up with the placement of the screw holes here, but I can work around that...)

... and the "Universal Block" module works perfectly! 8^) (I will upload a demo video in the next day or two.)


Amos wrote 01/29/2019 at 10:56 point

Success! I was able to bodge the expression board and this time I didn't let the smoke out. 8^)

I will be ordering some new, fixed PCBs and I am considering replacing the PCF8575 with an MCP23017 as the MCP23017 is in a bigger package which will be easier for my old fumble-fingers to manage. ;^) I will also re-do the Value block with corrected wiring (I managed to swap the position of the digits) and I will use the MCP23008 on that for consistency.

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Amos wrote 01/26/2019 at 10:53 point

Grrr!!! A fail on the Expression Module. a) SSOP ICs are danged hard to solder by hand (I should have found my solder paste and used hot air instead of my iron); and b) I screwed up the board layout and somehow managed to swap +5 and Gnd to the IC. It _looks_ okay, but there is definitely a short somewhere there... 8^/ I will redesign the board with the correct polarity _and_ try to find a suitable replacement IC that will be easier for me to solder. I am thinking MCP23017 might do the trick, as I can source that in a better package size than the PCF8575 I was trying to use... 

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Amos wrote 01/26/2019 at 05:52 point

Two (minor) issues with the PCBs so far... I soldered the wrong connector to the bottom of the Universal Blocks. This connector is for a Value Module (and/or Expression Module) which allows a block to read in a value (or expression) set by the operator. I wanted to use a female connector here, but in my excitement I soldered a male connector. An easy enough fix - just desolder and re-solder a new header.

The other issue is going to require a software solution - I got the digits swapped around on the Value Module. I haven't checked the Expression Module yet (I am not willing to try soldering an SSOP24 by hand with an iron and regular solder. I need to find my solder paste and use my new hot air station...) but I am guessing I made the same mistake. This is easily fixed in software, but I will need to do a rev2 of the board(s) and fix it permanently, as there are conveniences to be had with the digits around the right way.

But... The Universal Block and Value Module both work after some software tweaks, so that is a win in my book! 8^)

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