Tackling the problem for a few days now, I hope anyone has a helpful idea
What?
I am trying to get 2 Nunchuks to connect - both have the same I2C address. 1 is using the default I2C lanes and the other should be using SoftI2C
(1) and its Wiring interface with the code from "ArduinoNunchuk.cpp" & header ( made the results visible by using "DigiKeyboard" --
is there a way to get serial.print working on windows with the Arduino GUI? )
The reason?
No extra hardware, should be simple to use nearly the same code to request values from both Nunchuks with little delay.
The setup:
Nunchuks support 5v. So I connected the I2C, GNC, 5v directly to the first.
The second is connected to the same 5v and GND.
- For the data (SDA + SCL ) I used SDA_PIN 4, SCL_PIN 1. That seems to me the only way I can use the SoftI2C example "I2CScanSoftI2C" to at least detect it. The Wiring interface detects it too, if I remove the one write function thich won't compile.
The problems...
1. I do not seem to be able to start the Digispark with a Nunchuk connected to the mentioned pins.
2. I believe I have tried all cable positions of the left 4 pins for the SoftI2C and its PULLUP flag, and I can't seem to figure out, how this should work. At some point, right after the bootloader finished and the Digispark reconnected (DigiKeyboard) - it worked for 3 read outs. (The zButton / yButton did change on press.) The Digispark seemed to reboot after it.
3. I had trouble getting the DeviceIdentifier from the Nunchuk.
(2)4. Hardware I2C works flawlessly - so problem here.
Questions:
1. What would be the best pins?
2. Is P4 somehow directly connected to the micro-usb?
3. if I connect to P5 instead of P4, always seems to make the SoftI2C scanner to believe there is a device on every I2C address - something with the docs talking about 3v ?
4. Can I use P3/P4 for LEDs and more while using V-USB (related to Q2)?
5. Besides a I2C Mux, like "IC, MUX, 2CH, I2C, 8TSSOP PCA9540BDP By NXP" - is there a cheaper way and still causing little delay?
6. why do the I2C Nunchuk examples have a delay(10) after each transmission before each read - shouldn't the I2C device be faster then that?
7. Is there a way the see what speed the Nunchuk is using?
8. I trying to place modified arduino libs into my project folder - i can't seem to get this working - any idea / link to a documentation/explenation?
8. Suggestions?
Thanks for any help on this.
BA.
*1 ( felias-fogg-SoftI2CMaster- Software I2C Arduino library -
https://github.com/felias-fogg/SoftI2CMaster ) -> Config PORTC to PORTB, SDA_PIN 4, SCL_PIN 1, I2C_PULLUP 1
*2 Getting the DeviceIdentifier:
https://create.arduino.cc/projecthub/infusion/using-a-wii-nunchuk-with-arduino-597254#toc-3--read-the-device-ident-from-extension-register-11--- EDIT:
I believe I can verify, P3 and P4 being LOW/HIGH - IF the usb is connected. Powering by VCC(5V) and GND pins, P3/P4 don't seem to be affected. So I scratched the USB off the PCB, got a microUSB on PCB and wired the data lines back onto the board, and power to P3/P4. That seems to free P3 and P4 for use - and still allows powering by usb - and USB communication.
Found on the forums, referring to the docs: "3. Pin 3 and Pin 4 (P3 and P4) are used for USB communication and programming, while you can use them in your circuit if you are not using USB communication, you may have to unplug your circuit during programming if the circuit would impede the pin states or dramatically affect the voltage levels on these pins."
To handle the P5(reset, if wired to HIGH) there seems to be this, modify it (reset seems to be needed, if you use it as an ISP):
http://www.instructables.com/id/How-to-unlock-Digispark-ATtiny85-and-convert-it-to/
