ODROID-M1 Pinout Reference 
(Based on layout of https://randomnerdtutorials.com/esp32-pinout-reference-gpios/ )

The ODROID-M1 has a 40 pin header which breaks out 25(?) GPIO pins along with providing 3.3 and 5V DC power connections.

Source: https://wiki.odroid.com/_detail/odroid-m1/hardware/m1_40pinmap.png?id=odroid-m1%3Ahardware%3Aexpansion_connectors

ODROID-M1 Peripherals
•	2 Analog-to-Digital Converter (ADC) channels
•	1 x SPI interfaces
•	2(?) x UART interfaces
•	2 x I2C interfaces
•	1 x 1-Wire Interfaces
•	3 x PWM output channels
•	0 x Digital-to-Analog Converters (DAC)
•	? I2S interfaces ?
•	0 x Capacitive sensing GPIOs ?
•	1(?) x CAN bus

Notes

Header Pin	GPIO	WiringPi	Name	IN	OUT	Notes	Notes	
3	110	8	I2C.SDA0					
5	109	9	I2C.SCL0					
7	14	7	GPIO.14					
11	16	0	GPIO.16					
13	17	2	GPIO.17					
15	106	3	GPIO.106					
19	89	12	SPIO_MOSI					
21	88	13	SPIO_MISO					
23	91	14	SPI_CLK					
27	12	30	I2C.SDA1					
29	145	21	GPIO.145					
31	142	22	GPIO.142					
33	13	23	GPIO.13 					
35	125	24	GPIO.125					
8	126	15	TxD1					
10	127	16	TxR1					
12	120	1	GPIO.120					
16	118	4	GPIO.118					
18	119	5	GPIO.119					
22	121	6	GPIO.121					
24	90	10	SPI_CE0					
26	122	11	GPIO.122					
28	11	31	I2C_.SCL1					
32	123	26	GPIO.123 					
36	124	27	GPIO.124					

Input only Pins
None identified
Capacitive touch GPIO’s(?)
Not supported

Analog to Digital Converter (ADC)
https://wiki.odroid.com/odroid-m1/application_note/gpio/adc
ADC Available via pins 37 and 40
Limited to 1.8V Maximum
Digital to Analog Converter (DAC)
?
PWM
https://wiki.odroid.com/odroid-c4/application_note/gpio/pwm#tab__odroid-m1
Available via pins 33, 7, 15  and enabled via dtbo

I2C
Via pins 3 (SDA)&5 (SCL) or 27 (SDA) & 28 (SCL)

SPI
https://wiki.odroid.com/odroid-m1/application_note/gpio/spi

1-Wire
Still to be determined. https://forum.armbian.com/topic/15166-how-to-use-1-wire-for-ds18b20-on-odroid-n2/ suggests that on the N2 One-Wire is only available via GPIOX_7 (physically located where GPIO_3/Pin 15 is (M1)

Interrupts
Not supported

CAN Bus
Possibly start from this https://magazine.odroid.com/article/how-to-configure-and-use-the-can-bus-using-the-odroid-n2-with-microcontrollers/

Pins with special states at Boot
None identified

GPIO current drawn
Some discussion for the XU series at https://forum.odroid.com/viewtopic.php?t=5679 however that was targetted at the power pin. 
?