Brooke's World The life and ramblings of Brooke.

Spending some time brushing up on Python.  Spent some time learning about the Pillow 8.0.1 library in Python 3.9.1.

The image I started with.

from PIL import Image
import os

if __name__ == '__main__':
    # Open an image to get some basic info
    infile = "images/numbers-tiger-populations.jpg"
    im = Image.open(infile)
    print(f"""
bits {im.bits}
mode {im.mode}
size {im.size}
    """)

    # Show the image using the local viewer
    input("Press enter when you are ready to see the image.")
    im.show()

    # Create a thumbnail
    size = (128, 128)
    outfile = os.path.splitext(infile)[0] + ".thumbnail"
    with Image.open(infile) as im:
        im.thumbnail(size)
        im.save(outfile, "JPEG")

    # Show the thumbnail
    im = Image.open(outfile)
    input("Press enter when you are ready to see the thumbnail.")
    im.show()

    # convert to grayscale
    im = Image.open(infile).convert('LA')

    # Show the grayscale
    input("Press enter when you are ready to see the grayscale.")
    im.show()

I wrote the test sketch for the SN74HC595 and it works.  All sections of the SensorBoard v2 have tested as working.  My next task will be to write some firmware that takes advantage of all 5 sections.  Two temperature sensors, FRAM, photo resistor, and shift register with 8 LEDs.

Thought I would share a design mistake for the TeensyBreakout w/ SensorBoard v2. It turns out it is a good idea to keep in mind the physical design of your boards when you plan to stack them. I thought I had done pretty well, until I needed to press the reset button! That’s right. It took some creative re-purposing of an ink pen by borrowing its refill to sneak in there and press the button. I am thinking the rev 3 SensorBoard needs to either have a hole that goes through every single “shield” or bring a reset button up to at least the Teensybreakout.

I tested each of the Arduino sketches with the SensorBoard v2 on a Teensy 3.2 and they all worked. They covered both I2C temp sensors, the SPI FRAM, and the analog-read photoresistor ( values from about 20-1020 ).

The only chip I didn’t have a sketch written for yet was the SN74HC595 shift register. I am working on that sketch next.

As part of the CE Header project from the CE Skills course , we have a shift register on the SensorBoard. This chip allows us to light up 8 LEDs ( more with chip chaining ) with 3 pins.  I used a Bus Pirate (Dangerous Prototypes) and probes, from Seeed Studio, to iteratively poke at it until I understood how to talk to it via SPI.

I used a DIP version of the chip in a breadboard and wired it up to the Bus Pirate.  The LEDs are in the breadboard to see it working. Please note, the cable and connectors in the image below are from the Seeed probe cable. Some of the other probe cables have the colors in a different order on the connectors.

I used putty to connect to the Bus Pirate via a mini usb cable.

Note: If you decide to hook this up to an Arduino for testing, using an example sketch, here are the pins to use for your reference:

BP MOSI=pin 11
BP CLK=pin 12
BP CS=pin 8

Turn on output pins

Command	What it does	Output
[ 0b00000001 ]	Turn on LEDs.  Bit 1 is QA and bit 8 is QH.	QH QG QF QE QD QC QB QA                 0 0 0 0 0 0 0 1
[ 0b10000000 ]	Turn on LEDs	QH QG QF QE QD QC QB QA                 1 0 0 0 0 0 0 0
[ 0b10101010 ]	Turn on LEDs	QH QG QF QE QD QC QB QA                 1 0 1 0 1 0 1 0
[ 0b00000000 ]	Turn all LEDs off	QH QG QF QE QD QC QB QA                 0 0 0 0 0 0 0 0

Looking from the right side

Looking from the left

As part of the CE Header project from the CE Skills course , I decided to add an IC that used SPI to the SensorBoard. I chose the MB85RS64V chip. This is a Ferroelectric Random Access Memory (FRAM) integrated circuit.  It is similar to FLASH, but with some added benefits. The idea is to be able to write data to it and the data will persist between power off and power on cycles. I used a Bus Pirate (Dangerous Prototypes) and probes, from Seeed Studio, to iteratively poke at it until I understood how to talk to it via SPI.

Once I soldered the MB85RS64V to a small carrier board from Adafruit, I placed it on a breadboard and wired it up to the Bus Pirate. Please note, the cable and connectors in the image below are from the Seeed probe cable. Some of the other probe cables have the colors in a different order on the connectors.

I used putty to connect to the Bus Pirate via a mini usb cable.

Go ahead and power off with the w command, unplug the USB from the Bus Pirate, plug it back in.  Go through the set up steps and re-read the data, it should still be there!

It turns out that Adafruit sells this chip ready to go on a breakout board along with an Arduino library!

I released my very first Arduino library that can be found right in the Arduino IDE without having to download it and install it manually!  You can still download it and install manually if you like.  It supports the DS7505 temperature sensor.

Many thanks to Adafruit as I started with their MCP9808 library as my template.  I purchase from Adafruit several times a year.  Their products, service, and commitment to education is first class!

To add the library to your project, choose Sketch | Include Library | Manage Libraries … | Search for DS7505

The library supports basic functionality for the DS7505 Temperature Sensor.  Once you install the library, you can open the example sketch and go.

Here’s what the example looks like:

/**************************************************************************/
/*!
This is a demo for the DS7505
----> https://www.maximintegrated.com/en/products/analog/sensors-and-sensor-interface/DS7505.html

This code derived from the Adafruit_MCP9808_Library.

Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
*/
/**************************************************************************/

#include <Wire.h>
#include "MillaMilla_DS7505.h"

// Create the DS7505 temperature sensor object
MillaMilla_DS7505 tempsensor = MillaMilla_DS7505();

void setup() {
  delay(2000); // helpful on Teensy debugging to give time to open the serial monitor
  Serial.begin(9600);
  Serial.println("DS7505 demo");
  
  // Make sure the sensor is found, you can also pass in a different i2c
  // address with tempsensor.begin(0x48) for example
  if (!tempsensor.begin()) {
    Serial.println("Couldn't find DS7505!");
    while (1);
  }
}

void loop() {
  //Serial.println("wake up DS7505.... "); // wake up DS7505 for normal power use
  //tempsensor.wake();   // wake up, ready to read!  If you don't wake when shutdown, you still get a temp reading, it will be the last reading while awake.

  //tempsensor.write8(DS7505_REG_CONFIG, DS7505_REG_CONFIG_CONVRESOL_12_BITS); // change default precision from default of 9 bits

  // Read and print out the temperature, then convert to *F
  float c = tempsensor.readTempC();
  float f = c * 9.0 / 5.0 + 32;
  Serial.print("Temp: "); Serial.print(c); Serial.print("*C\t"); 
  Serial.print(f); Serial.println("*F");
  
  //Serial.println("Shutdown DS7505.... ");
  //tempsensor.shutdown(); // shutdown DS7505 for low power
  
  delay(1000);
}

If you have a library you would like added to the Arduino IDE, check out the Library Manager FAQ.  It is a very easy to follow reference.  It only took about 2 1/2 days from when I created my issue for it to be found by the IDE.  Thank you to the Library Manager Team!!