Solarduino V2

Welcome Spring,

I got the SoarDuino V2 board populated yesterday, and tested the Solar Piston portion of the circuit. Works charmingly.

This is the top of the board. I used the ProtoMat S62 at Parsons to cut this board. One slight issue with the fabrication is that none of the through holes are plated. I had to solder in the vias and hit bottoms and tops of all the pads. Tedious! In this photo, I have not soldered header rows at top and bottom.

This is the bottom.

Here’s a video of the Solar Piston at work. Battery V is ~3.2V.

This is the same Solar Piston V2 as described in the link below.
Next I tested the Voltage regulator circuit (TPS75501) and got 5V at the output! I am using an FTDI cable known to folks who’ve played with the Boarduino or Ardweenie for power and programming. My V-reg is adjusted to output 3.5V. The 5V was not what I was expecting! After probing around I found the FB pin (V-reg pin5) was shorted to GND by a whisp of solder. A little scraping and that cleared it up.

Now I’ve got the 3.5V I expect. The actual power to the board from this circuit suffers a slight voltage drop (Shottkey)  to clock in at a comfortable 3.36V. This will settle under load to abut 3.3V.

In this photo, the meter is reading pin 7 (Vcc) on the arduino chip socket.

Now it’s time to slap in the chip and say hello!

This is a simple blink program. I’ve verified programming through the FTDI USB cable, and read Serial.print data from the board. Next will be to communicate to the rest of my hardware:
MCP4551 Digi Pot (used to read Voltage level)
APDS-9301 Ambient Light Sensor (returns a value in lux)
DS3231 Real Time Clock (I will get temperature data from this as well!)
SD Card (where my data will be stored)

Cheers, Joel

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3 Responses to Solarduino V2

  1. Luis Lima says:

    Hello, I saw that you are using an APDS-9301 sensor in your project, were you able to collect meaninfull LUX values from it? I am also using one of these in a project, but it always reports very low values of LUX, for example, a desk lamp pointing directly at it only reads 90Lux, which seems very little. Thanks for your help

    • Futurologist says:

      Hi, I posted the latest firmware on the Downloads page. You can tease out the APDS code that I’m using. The trick to get ‘reliable’ lux data is to use the correct gain and integration timing for the amount of light available. I’m taking an initial reading, and then making adjustments. It helped to first run some code that barfed out the lux values for each gain and integration time setting, so I could see how the data was changing given different light conditions. with a range from 0.02 (moonless night) to 10,000 (direct sunlight) it’s important to massage the numbers.