Is it possible to use the Analog pins on the Neo as outputs? For example I've tried addressing A2 as: A2 14+2 54+2 ie: pinMode( A2, OUTPUT ); digitalWrite( A2, HIGH ); and int ledPin = 14+2; // Arduino Uno addressing (http://forum.arduino.cc/index.php?topic=28720.0) //int ledPin = 54+2; // Arduino Mega adressing pinMode( ledPin, OUTPUT ); digitalWrite( ledPin, HIGH ); But no luck -- I've been using the Arduino Web IDE.
Not of any help for you but I can confirm that it is not working as on an Arduino UNO. You can't use the A0-A5 Pins as a Digital output. On an Arduino UNO it is possible: http://www.instructables.com/id/How-to-add-6-extra-pins-to-your-Arduino-with-no-ex/ @Andrea Rovai, any ideas? It is not widely documented on the Arduino site but on https://www.arduino.cc/en/Reference/PinMode it is stated in the Note that I tried it with the blink example with pin declaration 14 and A0 (should be the same pin) but with both declarations no blinking LED. Example with Pin 14 Code: void setup() { pinMode(14, OUTPUT); } void loop() { digitalWrite(14, HIGH); delay(300); digitalWrite(14, LOW); delay(300); }
Might be an issue with the wiring_digital.c file of the Arduino board manager package. Though, I don't have enough experience to know for sure. Paging @ektor5
Each Analog pin/Digital pin is multiplexed by a gpio pin as declared in the dts: Code: // Multiplexer pins for GPIO/ADC (J5) MX6SX_PAD_RGMII2_TXC__GPIO5_IO_23 0x80000000 // MUX_A MX6SX_PAD_RGMII2_RX_CTL__GPIO5_IO_16 0x80000000 // MUX_B MX6SX_PAD_QSPI1A_SCLK__GPIO4_IO_21 0x80000000 // MUX_C MX6SX_PAD_QSPI1A_SS0_B__GPIO4_IO_22 0x80000000 // MUX_D MX6SX_PAD_QSPI1A_DATA2__GPIO4_IO_18 0x80000000 // MUX_E MX6SX_PAD_QSPI1A_DATA3__GPIO4_IO_19 0x80000000 // MUX_F In uboot the above pins are set low to enable ADC input. As a test trying setting the pins to high from the linux side and then running your script (this may not work). What I'm not sure about is which gpio pins (the adc pins) map to on the the arduino side.
Then a few more gpios like LWGPIO_MUX_PORT4_PIN24_GPIO need to be made available along with the mux pins.
If it's due to the wiring_digital.c file, details of the additional IO text entries can be found on the following page - http://www.udoo.org/docs-neo/Arduino_M4_Processor/Use_more_digital_pins_on_M4.html
Thanks for all the help! The schematics show multiplexers to switch the analog port pins between the ADC and GPIO pins (see attached). However I can't see any mention of the iMX6 port names in this: http://www.udoo.org/docs-neo/Arduino_M4_Processor/Use_more_digital_pins_on_M4.html
Someone can give the Udoo team some information in what direction they have search how to solve this issue? It seems that they are struggling with this.
I feel it's related to the board package not including the analog pins in the default wiring digital file, which is where the digitalWrite function is sourced from. Unfortunately, I don't have a NEO to test on. If anyone wishes to try it, copy the extra pins & const array from: http://www.udoo.org/docs-neo/Arduino_M4_Processor/Use_more_digital_pins_on_M4.html over to the wiring_digital.c file in your board package used by Arduino IDE
For now I will do a hardware mod to work around this problem on my project. @Andrea Rovai -- has Udoo added this to their to do / issues list so that this just works "out of the box" in the future?
It is on the list but they are not sure how to fix it. See also http://www.udoo.org/forum/index.php?threads/4513/
I looked into this but i do not think it will work. On Arduino Uno Pin A0-A5 can also be addressed as Pin 14-19 But in the extra pins & const array Pin 14-19 are mapped to A9 pins and the SDA/SCL pins, see also picture below.
I'll give it a try. Edit: How to do this from Linux? I cannot do echo 1 > /gpio/pinA5/value Pin 16 is a pin on the A9 side. So how to adress Arduino Pin A0-A5 from Linux? Edit 2: hmm, going to try this: http://www.udoo.org/forum/threads/exporting-arduino-analog-pins-possible.3215/#post-15725 Edit 3: Edit deleted..... Edit 4: Edit deleted..... Edit 5: Need to calculate again, stupid! will use A0 as in the example of jas-mx Edit 6: OK, got a High A0 pin by setting it by Linux, now try to get it blink by Arduino: # Set multiplexer to GPIO support echo 118 > /sys/class/gpio/export echo out > /sys/class/gpio/gpio118/direction echo 1 > /sys/class/gpio/gpio118/value # Set GPIO line to output echo 120 > /sys/class/gpio/export echo out > /sys/class/gpio/gpio120/direction echo 1 > /sys/class/gpio/gpio120/value Edit 7: Changing the Arduino board definition: changed /usr/share/arduino/hardware/UDOO/solox/variants/udooneo/wiring_digital.h #define ARD_NMAX_DIO 15 changed /usr/share/arduino/hardware/UDOO/solox/variants/udooneo/wiring_digital.c added #define ARD_DIO14 (LWGPIO_PORT4 | LWGPIO_PIN24) #define ARD_DIO14_MUX_GPIO (LWGPIO_MUX_PORT4_PIN24_GPIO) and {ARD_DIO14, ARD_DIO14_MUX_GPIO}, // 14 = A0 Edit 7: YES, I got a blinking Led with digitalWrite(14, HIGH/LOW) on pin A0!!! But I suppose I cannot use the AnalogRead on A0 anymore because I set multiplexer to GPIO in Step 6. Also when I reboot the sketch will fail so I will now reset it to pin 13 again. Edit 8: Tested AnalogRead(A0) but no real values as expected, just giving a approx 684 whatever voltage I put on it. AnalogRead(A1) gives real values between 0-1023 (0-3.3V)
Given my tests it is possible to address A0-A5 as a digital pin but only with some major changes from the Linux side and in wiring_digital.c/h. And after a reboot you have to do the multiplexer part again. Is it possible to set the multiplexer of an analog pin to GPIO within wiring_digital.c when the pinmode of an Analog pin is set to output?
