Page 6 - Programming the Microduino

Now that you have all the required physical parts placed for the logic frame, we will take the first step in functional assembly, with a total of 3 major wiring maps.

The first step is to connect the Microduino to the programming port, allowing FTDI programming via a FTDI - USB module. The placement of the programming port makes this relatively simple. We will also run power and ground through the central power regulator, which only needs to be done once.

The Microduino Programming Schematic:


1.) review schematic

First, review the schematic. This is really useful when testing / debugging. The schematic shows a simple RX / TX / V / G / RST connection, but running the voltage and ground to the power regulator. I do this so there is a central power / ground letting you power both the microduino and (later on) the BLE112 while using a FTDI - USB adapter. This also shields the hardware a bit, as the regulator will take any voltage spike hits first.

2.) Connect TX / RX / RST

3 of the 5 connections can go directly into the Microduino, and are the only pin connections. This means we simply run the connection port wire directly into the Microduino. Power and Ground need to be shared / routed differently, and we will do that in the next step.

Solo Connections


3.) Connect Ground / Power to Regulator

The other two pins need to be shared, and connected to the regulator. We also do some planning ahead here. Ground is a feed that many other connections will need, and re-soldering new ground feeds will create more of a headache. For ground, I pass through the ground feed from the connection port down into the ground pin on the microduino. Then, on the underside, I add 3 more micro wire leads. 2 will go down the gap on the left side (looking down on an upside down logic frame). 1 feed will go down to the power regulator ground. The other will be used later for buttons on this side. The 3rd ground feed will go to the oppisite gap on the right side, to be used for buttons on that side.

The power line from the programming port will follow the 2 ground feeds in the left side gap, and go down to the power regulator VIN. To make the wires lay flat, use a dremel tool / soldering iron to make a small canal in the logic frame where 3 wires can pass through without adding height to the logic frame. Use some super glue to hold them down. Do the same on the other end of the gap, next to the power regulator, and give the power regulator its VIN and ground feeds from the programming port.


When running any wires, make sure they do not add to the 3mm height of the logic frame!

Running Ground / Power


When you connect the VIN feed to the regulator, add an extra wire feed, to be used later to get the battery power. Once you have power and ground to the regulator, run a line from VOUT to 3V3 on the Microduino through the small gap between the regulator and the BLE112 module. The 3V3 pin is very close to the gap, so it's an easy run.

Power to Converter


4.) Test Programming

First, bust out the multimeter set to continuity. Let's make sure that all of the above connections are live, and that we didn't join power to ground (a quick way to fry parts) once it seems sane enough to plug in, use an FTDI to USB adapter, a capacitor (for the reset line) and some jumper wire to connect the programming port to your computer. Forget which pins are which? Here's a reminder(left to right, Pins North, looking down into holes):

1 = Gnd
2 = Arduino Reset
3 = Power
7 = Ard TX
8 = Ard Rx

If all goes well, just plugging it in will light up the Red power LED, and you should be able to programming successfuly the microduino as you would any other FTDI Arduino compatible. Don't forget to select the right Microduino & serial port (I.E. something like Microduino Core + (Atmega644PA@8M, 3.3V) on /dev/tty/usbserial-AM01QYNS)



Next Page - Program the BLE112

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