Week 10 Assignments

This week we must create a board that contains an input to device and measure it from the computer. As I want to create an interactive playground, I'll opt for light sensors to detect when players cover joints with their hands.

I used hello.light board for this week, that includes a phototransitor to detect light. I milled the board using Modela MDX and soldered it. These are the required components:

Here it is the resulting board:

To upload the code, I used the avr programmer connected to the ICSP header to upload the file:

Afrodita:FabAcademy satch$ cat hello.light.45.make
PROJECT=hello.light.45
SOURCES=$(PROJECT).c
MMCU=attiny45
F_CPU = 8000000

CFLAGS=-mmcu=$(MMCU) -Wall -Os -DF_CPU=$(F_CPU)

$(PROJECT).hex: $(PROJECT).out
        avr-objcopy -O ihex $(PROJECT).out $(PROJECT).c.hex;\
   avr-size --mcu=$(MMCU) --format=avr $(PROJECT).out

$(PROJECT).out: $(SOURCES)
        avr-gcc $(CFLAGS) -I./ -o $(PROJECT).out $(SOURCES)

program-bsd: $(PROJECT).hex
        avrdude -p t45 -c bsd -U flash:w:$(PROJECT).c.hex

program-dasa: $(PROJECT).hex
        avrdude -p t45 -P /dev/ttyUSB0 -c dasa -U flash:w:$(PROJECT).c.hex

program-avrisp2: $(PROJECT).hex
        avrdude -p t45 -P usb -c avrisp2 -U flash:w:$(PROJECT).c.hex

program-usbtiny: $(PROJECT).hex
        avrdude -p t45 -P usb -c usbtiny -U flash:w:$(PROJECT).c.hex

program-dragon: $(PROJECT).hex
        avrdude -p t45 -P usb -c dragon_isp -U flash:w:$(PROJECT).c.hex

Afrodita:FabAcademy satch$ sudo make -f hello.light.45.make program-avrisp2
Password:
avr-gcc -mmcu=attiny45 -Wall -Os -DF_CPU=8000000 -I./ -o hello.light.45.out hello.light.45.c
avr-objcopy -O ihex hello.light.45.out hello.light.45.c.hex;\
   avr-size --mcu=attiny45 --format=avr hello.light.45.out
AVR Memory Usage
----------------
Device: attiny45

Program:     530 bytes (12.9% Full)
(.text + .data + .bootloader)

Data:          1 bytes (0.4% Full)
(.data + .bss + .noinit)


avrdude -p t45 -P usb -c avrisp2 -U flash:w:hello.light.45.c.hex

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude: Device signature = 0x1e9206
avrdude: NOTE: FLASH memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "hello.light.45.c.hex"
avrdude: input file hello.light.45.c.hex auto detected as Intel Hex
avrdude: writing flash (530 bytes):

Writing | ################################################## | 100% 0.20s

avrdude: 530 bytes of flash written
avrdude: verifying flash memory against hello.light.45.c.hex:
avrdude: load data flash data from input file hello.light.45.c.hex:
avrdude: input file hello.light.45.c.hex auto detected as Intel Hex
avrdude: input file hello.light.45.c.hex contains 530 bytes

avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 0.17s

avrdude: verifying ...
avrdude: 530 bytes of flash verified

avrdude: safemode: Fuses OK

avrdude done.  Thank you.

To read values from the console I used the hello.light.45.py file. I installed PySerial previously, but somehow I got these errores related to permissions and some missing files.

Afrodita:FabAcademy satch$ ./hello.light.45.py /dev/tty.usbserial-FTF3M8JF
-bash: ./hello.light.45.py: Permission denied
Afrodita:FabAcademy satch$ sudo ./hello.light.45.py /dev/tty.usbserial-FTF3M8JF
Password:
sudo: ./hello.light.45.py: command not found
Afrodita:FabAcademy satch$ chmod +x hello.light.45.py 
Afrodita:FabAcademy satch$ sudo ./hello.light.45.py /dev/tty.usbserial-FTF3M8JF
from: can't read /var/mail/Tkinter
dyld: Library not loaded: /usr/local/lib/libltdl.7.dylib
  Referenced from: /usr/local/bin/import
  Reason: image not found
./hello.light.45.py: line 16: 62833 Trace/BPT trap: 5       import serial
./hello.light.45.py: line 18: WINDOW: command not found
./hello.light.45.py: line 19: eps: command not found
./hello.light.45.py: line 20: filter: command not found
./hello.light.45.py: line 22: syntax error near unexpected token `('
./hello.light.45.py: line 22: `def idle(parent,canvas):'
Afrodita:FabAcademy satch$ 

I did some basic troubleshooting but in the end, I just discovered I also missed some TKinter files. Following this python tutorial I determined I needed to install and configure ActiveTcl 8.5.14 for my 2.7.x 64 bits python release.

Afterwards I was able to run the code without problems. I was surpised as the counter ran in the opposite direction I expected, running high under no light and viceversa. I also determined that de dynamic range of this particular sensor is not very suited to indoors, as it always oscilated between 930 and 1024.