This repository contails files related to OpeNITHM.
Firmware, schematics, board layout, and CAD files are included in this repo. Please see the CAD directory for the original 3d printed version, or the v2-cad directory for the laser cut version.
In the CAD\STL folder, you will find numerous parts that must be 3D printed.
Please check out the wiki for more information.
| Part | Qty |
|---|---|
| Center Frame | 1 |
| Right Frame | 1 |
| Left Frame | 1 |
| Key Dual 2.5mm OR Key Dual 3mm1 | 16 |
| LED Support Peg | 16 |
| Sensor Rail | 2 |
| Sensor Spacer Left2 | 1 |
| Sensor Base Left2 OR Integrated Sensor Base Left2 | 1 |
| Sensor Cover Left2 | 1 |
| Integrated Frame Mount Left2,3 | 1 |
NOTES:
- Use 2.5mm for 3/32" and 3mm for 1/8" acrylic.
- Print out mirrored version of these parts as well.
- Only print the frame mount if you are using the integrated sensor.
The non-printed materials and hardware include:
| Part | Qty |
|---|---|
| 4-40 Flat Head Screw, length 3/16" to 5/16" will work OR M3 equivalent | 2 |
| Top Acrylic Plate1 (472mm x 112mm) | 1 |
| Key Acrylic1 (103.5mm x 26mm) | 16 |
| Copper Tape, cut into rectangles 95mm x 26mm | 16 |
NOTES:
- Use 2.5mm (3/32") OR 3mm (1/8") acrylic. Use the same acrylic for top plate and keys.
OpeNITHM is designed for the Teensy LC.
The biggest reason is that Teensy has built in capacitive sensing, which is how OpeNITHM fuctions. You have to fake it on Arduino using very controlled analog reads, and it is nowhere near as sensitive. In my (VXZK's) experience, it was simply impossible to use an Arduino to do the capacitive sensing required for this project.
I chose the Teensy LC as it is the lowest cost Teensy model available with capacitive sensing. The firmware and PCB are designed for this board alone; significant modifications may be required for any other version.
There is an alternative build using an Arduino Pro Micro and 2 MPR121s as a branch in this repo, but it is not maintained and not recommended. You're on your own with that one!
Links are mostly suggestions (except the Teensy, which is only officially available through the PJRC site and authorized resellers).
(VXZK: I've heard a lot of trouble regarding good quality IR leds and phototransistors, so I've included specific links to the ones I purchased and has worked well for me.)
The links below also assume you want to socket your Teensy and multiplexers for later use. You can solder them directly, if you'd like.
If you are going to solder your sensors directly to the PCB, it is not necessary buy the 0.1" Pin Header, Right Angle. Otherwise, include female 0.1" sockets for your sensors (commonly referred to as Dupont connectors).
| Part | Link | Qty |
|---|---|---|
| Teensy LC | https://www.pjrc.com/store/teensylc.html | 1 |
| Teensy LC Breakout Board | this Github, Circuit-Teensy32 folder contains gerbers | 1 |
| 74HC4051 Multiplexer Breakout Board | Aliexpress | 4 |
| 0.1" Pin Header, 1 row, 40 pos | Aliexpress (qty 10) | 2 |
| 0.1" Pin Header, Right Angle, 2 row, 24 pos | LCSC | 2 |
| 0.1" Socket, Straight, 1 row, 14 pos | LCSC | 2 |
| 0.1" Socket, Straight, 1 row, 5 pos | LCSC | 2 |
| 0.1" Socket, Straight, 1 row, 11 pos | LCSC | 2 |
| 0.1" Socket, Straight, 1 row, 8 pos | LCSC | 2 |
| 51k ohm Resistor, 1/6W or 1/8W | LCSC or Aliexpress | 6 |
| 33 ohm Resistor, 1/4W, 1/6W, or 1/8W | LCSC or Aliexpress | 3 |
| 1m WS2812B RGB 5V LED Strip, 30LED Per Meter | Aliexpress | 1 |
| IR LED and Phototransistor | Ebay (Qty 20 pairs) | 6 |
As of 2020-07-17, the recommended board version is v2.1, which features inputs for 32 sensors. This best replicates the feeling of the arcade. Previous versions used 16 sensors. If you still wish to make a 16 key version, you can order the v2.1 but only populate two of the multiplexers. This is not really recommended.
NOTE: This firmware is only written to work for the Teensy LC. Do not use Teensy 2.0 or Teensy 3.x
Skip this section if you are using a Pro Micro.
Locate your arduino folder (usually C:\Program Files (x86)\arduino).
Copy Firmware/Teensy/boards.txt to arduino\hardware\teensy\avr\ and overwrite the existing.
Copy Firmware/Teensy/teensy3 to arduino\hardware\teensy\avr\cores\teensy3 and overwrite any conflicts.
Copy Firmware/FastLED/WS2812Serial.cpp and Firmware/FastLED/WS2812Serial.h to arduino\hardware\teensy\avr\libraries\WS2812Serial and overwrite the existing.
Copy Firmware/FastLED/FastLED.cpp and Firmware/FastLED/FastLED.h to [My Documents]\Arduino\libraries\FastLED\ and overwrite the existing.
(It is easier to copy and paste from the files in Firmware/Teensy instead of through here, the below is just for reference.)
Add usb_nkro.c and usb_nkro.h to arduino\hardware\teensy\avr\cores\teensy3
In arduino\hardware\teesny\avr\boards.txt add lines 1175-1179
1175 teensyLC.menu.usb.nkrokeyboard=NKRO Keyboard
1176 teensyLC.menu.usb.nkrokeyboard.build.usbtype=USB_NKRO
1177 teensyLC.menu.usb.nkrokeyboard.fake_serial=teensy_gateway
1178 teensyLC.menu.usb.serialnkrokeyboard=Serial + NKRO Keyboard
1179 teensyLC.menu.usb.serialnkrokeyboard.build.usbtype=USB_SERIAL_NKRO
In `arduino\hardware\teensy\avr\cores\teensy3\WProgram.h` add line 59
```c
58 #include "usb_joystick.h"
59 #include "usb_nkro.h"
60 #include "usb_midi.h"In arduino\hardware\teensy\avr\cores\teensy3\usb_inst.cpp add lines 75-77
72 usb_serial_class Serial;
73 #endif
74
75 #ifdef NKRO_INTERFACE
76 usb_nkro_class Nkro;
77 #endif
78
79 #else // F_CPU < 20 MHzIn arduino\hardware\teensy\avr\cores\teensy3\usb_dev.h add lines 93-98
90 extern volatile uint8_t keyboard_leds;
91 #endif
92
93 #ifdef NKRO_INTERFACE
94 extern uint8_t nkro_report_data[NKRO_SIZE];
95 extern uint8_t nkro_protocol;
96 extern uint8_t nkro_idle_config;
97 extern uint8_t nkro_idle_count;
98 #endif
99
100 #ifdef MIDI_INTERFACEIn arduino\hardware\teensy\avr\cores\teensy3\usb_desc.h add lines 868-948
866 #define ENDPOINT15_CONFIG ENDPOINT_TRANSMIT_ONLY
867
868 #elif defined(USB_NKRO)
869 #define VENDOR_ID 0x16C0
870 #define PRODUCT_ID 0x04D0
871 #define MANUFACTURER_NAME {'T','e','e','n','s','y','d','u','i','n','o'}
872 #define MANUFACTURER_NAME_LEN 11
873 #define PRODUCT_NAME {'N','K','R','O',' ','K','e','y','b','o','a','r','d'}
874 #define PRODUCT_NAME_LEN 13
875 #define EP0_SIZE 64
876 #define NUM_ENDPOINTS 5
877 #define NUM_USB_BUFFERS 14
878 #define NUM_INTERFACE 4
879 #define SEREMU_INTERFACE 1 // Serial emulation
880 #define SEREMU_TX_ENDPOINT 1
881 #define SEREMU_TX_SIZE 64
882 #define SEREMU_TX_INTERVAL 1
883 #define SEREMU_RX_ENDPOINT 2
884 #define SEREMU_RX_SIZE 32
885 #define SEREMU_RX_INTERVAL 2
886 #define KEYBOARD_INTERFACE 0 // Keyboard
887 #define KEYBOARD_ENDPOINT 3
888 #define KEYBOARD_SIZE 8
889 #define KEYBOARD_INTERVAL 1
890 #define KEYMEDIA_INTERFACE 2 // Keyboard Media Keys
891 #define KEYMEDIA_ENDPOINT 4
892 #define KEYMEDIA_SIZE 8
893 #define KEYMEDIA_INTERVAL 4
894 #define NKRO_INTERFACE 3 // NKRO Keyboard
895 #define NKRO_ENDPOINT 5
896 #define NKRO_SIZE 32
897 #define NKRO_REPORT_KEYS ( NKRO_SIZE - 1 )
898 #define NKRO_INTERVAL 1
899 #define ENDPOINT1_CONFIG ENDPOINT_TRANSMIT_ONLY
900 #define ENDPOINT2_CONFIG ENDPOINT_RECEIVE_ONLY
901 #define ENDPOINT3_CONFIG ENDPOINT_TRANSMIT_ONLY
902 #define ENDPOINT4_CONFIG ENDPOINT_TRANSMIT_ONLY
903 #define ENDPOINT5_CONFIG ENDPOINT_TRANSMIT_ONLY
904 #define ENDPOINT6_CONFIG ENDPOINT_TRANSMIT_ONLY
905
906 #elif defined(USB_SERIAL_NKRO)
907 #define VENDOR_ID 0x16C0
908 #define PRODUCT_ID 0x0487
909 #define DEVICE_CLASS 0xEF
910 #define DEVICE_SUBCLASS 0x02
911 #define DEVICE_PROTOCOL 0x01
912 #define MANUFACTURER_NAME {'T','e','e','n','s','y','d','u','i','n','o'}
913 #define MANUFACTURER_NAME_LEN 11
914 #define PRODUCT_NAME {'S','e','r','i','a','l','/','N','K','R','O',' ','K','e','y','b','o','a','r','d'}
915 #define PRODUCT_NAME_LEN 20
916 #define EP0_SIZE 64
917 #define NUM_ENDPOINTS 6
918 #define NUM_USB_BUFFERS 14
919 #define NUM_INTERFACE 5
920 #define CDC_IAD_DESCRIPTOR 1
921 #define CDC_STATUS_INTERFACE 0
922 #define CDC_DATA_INTERFACE 1 // Serial
923 #define CDC_ACM_ENDPOINT 2
924 #define CDC_RX_ENDPOINT 3
925 #define CDC_TX_ENDPOINT 4
926 #define CDC_ACM_SIZE 16
927 #define CDC_RX_SIZE 64
928 #define CDC_TX_SIZE 64
929 #define KEYBOARD_INTERFACE 2 // Keyboard
930 #define KEYBOARD_ENDPOINT 1
931 #define KEYBOARD_SIZE 8
932 #define KEYBOARD_INTERVAL 1
933 #define KEYMEDIA_INTERFACE 3 // Keyboard Media Keys
934 #define KEYMEDIA_ENDPOINT 5
935 #define KEYMEDIA_SIZE 8
936 #define KEYMEDIA_INTERVAL 4
937 #define NKRO_INTERFACE 4 // NKRO Keyboard
938 #define NKRO_ENDPOINT 6
939 #define NKRO_SIZE 32
940 #define NKRO_REPORT_KEYS ( NKRO_SIZE - 1 )
941 #define NKRO_INTERVAL 1
942 #define ENDPOINT1_CONFIG ENDPOINT_TRANSMIT_ONLY
943 #define ENDPOINT2_CONFIG ENDPOINT_TRANSMIT_ONLY
944 #define ENDPOINT3_CONFIG ENDPOINT_RECEIVE_ONLY
945 #define ENDPOINT4_CONFIG ENDPOINT_TRANSMIT_ONLY
946 #define ENDPOINT5_CONFIG ENDPOINT_TRANSMIT_ONLY
947 #define ENDPOINT6_CONFIG ENDPOINT_TRANSMIT_ONLY
948 #endif
949
950 #ifdef USB_DESC_LIST_DEFINEIn arduino\hardware\teensy\avr\cores\teensy3\usb_desc.c add lines 239-265
236 };
237 #endif
238
239 #ifdef NKRO_INTERFACE
240 // Via https://dawnmist.dreamwidth.org/1250.html
241 static uint8_t nkro_hid_report_desc[] = {
242 0x05, 0x01, // Usage Page (Generic Desktop),
243 0x09, 0x06, // Usage (Keyboard),
244 0xA1, 0x01, // Collection (Application),
245 // bitmap of modifiers
246 0x75, 0x01, // Report Size (1),
247 0x95, 0x08, // Report Count (8),
248 0x05, 0x07, // Usage Page (Key Codes),
249 0x19, 0xE0, // Usage Minimum (224),
250 0x29, 0xE7, // Usage Maximum (231),
251 0x15, 0x00, // Logical Minimum (0),
252 0x25, 0x01, // Logical Maximum (1),
253 0x81, 0x02, // Input (Data, Variable, Absolute), ;Modifier byte
254 // bitmap of keys
255 0x95, NKRO_REPORT_KEYS*8, // Report Count (),
256 0x75, 0x01, // Report Size (1),
257 0x15, 0x00, // Logical Minimum (0),
258 0x25, 0x01, // Logical Maximum(1),
259 0x05, 0x07, // Usage Page (Key Codes),
260 0x19, 0x00, // Usage Minimum (0),
261 0x29, NKRO_REPORT_KEYS*8-1, // Usage Maximum (),
262 0x81, 0x02, // Input (Data, Variable, Absolute),
263 0xc0 // End Collection
264 };
265 #endif
266
267 #ifdef JOYSTICK_INTERFACE
268 #if JOYSTICK_SIZE == 12In arduino\hardware\teensy\avr\cores\teensy3\usb_desc.c add lines 603-610 and modify line 612
600 #define MULTITOUCH_INTERFACE_DESC_SIZE 0
601 #endif
602
603 // Via https://dawnmist.dreamwidth.org/1250.html
604 #define NKRO_INTERFACE_DESC_POS MULTITOUCH_INTERFACE_DESC_POS+MULTITOUCH_INTERFACE_DESC_SIZE
605 #ifdef NKRO_INTERFACE
606 #define NKRO_INTERFACE_DESC_SIZE 9+9+7
607 #define NKRO_HID_DESC_OFFSET NKRO_INTERFACE_DESC_POS+9
608 #else
609 #define NKRO_INTERFACE_DESC_SIZE 0
610 #endif
611
612 #define CONFIG_DESC_SIZE NKRO_INTERFACE_DESC_POS+NKRO_INTERFACE_DESC_SIZE
613
614
615
616 // **************************************************************In arduino\hardware\teensy\avr\cores\teensy3\usb_desc.c add lines 1131-1158
1129 #endif // JOYSTICK_INTERFACE
1130
1131 #ifdef NKRO_INTERFACE
1132 // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
1133 9, // bLength
1134 4, // bDescriptorType
1135 NKRO_INTERFACE, // bInterfaceNumber
1136 0, // bAlternateSetting
1137 1, // bNumEndpoints
1138 0x03, // bInterfaceClass (0x03 = HID)
1139 0x00, // bInterfaceSubClass (0x01 = Boot)
1140 0x00, // bInterfaceProtocol (0x01 = Keyboard)
1141 0, // iInterface
1142 // HID interface descriptor, HID 1.11 spec, section 6.2.1
1143 9, // bLength
1144 0x21, // bDescriptorType
1145 0x11, 0x01, // bcdHID
1146 0, // bCountryCode
1147 1, // bNumDescriptors
1148 0x22, // bDescriptorType
1149 LSB(sizeof(nkro_hid_report_desc)), // wDescriptorLength
1150 MSB(sizeof(nkro_hid_report_desc)),
1151 // endpoint descriptor, USB spec 9.6.6, page 269-271, Table 9-13
1152 7, // bLength
1153 5, // bDescriptorType
1154 NKRO_ENDPOINT | 0x80, // bEndpointAddress
1155 0x03, // bmAttributes (0x03=intr)
1156 NKRO_SIZE, 0, // wMaxPacketSize
1157 NKRO_INTERVAL, // bInterval
1158 #endif // NKRO_INTERFACE
1159
1160 #ifdef MTP_INTERFACEIn arduino\hardware\teensy\avr\cores\teensy3\usb_desc.c add lines 1602-1605
1600 {0x2100, MULTITOUCH_INTERFACE, config_descriptor+MULTITOUCH_HID_DESC_OFFSET, 9},
1601 #endif
1602 #ifdef NKRO_INTERFACE
1603 {0x2200, NKRO_INTERFACE, nkro_hid_report_desc, sizeof(nkro_hid_report_desc)},
1604 {0x2100, NKRO_INTERFACE, config_descriptor+NKRO_HID_DESC_OFFSET, 9},
1605 #endif
1606 #ifdef MTP_INTERFACEIn arduino\hardware\teensy\avr\boards.txt add lines 1175-1177
1174 teensyLC.menu.usb.flightsim.fake_serial=teensy_gateway
1175 teensyLC.menu.usb.nkrokeyboard=NKRO Keyboard
1176 teensyLC.menu.usb.nkrokeyboard.build.usbtype=USB_NKRO
1177 teensyLC.menu.usb.nkrokeyboard.fake_serial=teensy_gateway
1178 teensyLC.menu.usb.disable=No USB
There are a number of options built into the firmware to give you flexibility in your implementation. These are presented as preprocessor defines that can be commented and uncommented to fit.
All user-editable defines are in Config.h, see the comments for additional information.
If you are not using either the Pro Micro or Teensy LC boards provided in this repo, it may be necessary to change the definitions of the pins, located in PinConfig.h.
If you do not have the FastLED and HID-Project libraries installed, do so though the Tools->Manage Libraries menu.
When using a Pro Micro, select Arduino/Genuino Micro from Tools->Board.
When using a Teensy LC, select Teensy LC from Tools->Board, then select NKRO Keyboard from Tools->USB Type for reactive lights. If you are using serial light updates, select Serial + NKRO Keyboard.
Prior to compilation, review the (numerous) options available to the end user in Config.h. Comment and uncomment the corresponding options that match your setup.
The firmware is now largely self-configuring, as it determines thresholds for the sensors at every power on. However, you may wish to adjust the tolerance values that the automatic calibration works under. This can be done for both the keys and the air sensors.
In AutoTouchboard.h, there are two variables that affect how sensitive your keys are, deltaThreshold and releaseThreshold. deltaThreshold is the value that determines how much the key readings must change to register a press - increasing this requires a harder press to register, and decreasing it requires a softer press. If, for example, you are experiencing the keys registering a touch before you actually touch them, increase this value. releaseThreshold is the change requried to detect a release - this usually does not need to be modified.
In AirSensor.h, there is a const named AIR_INPUT_DETECTION which defaults to 0.9. This is the percentage of the maximum reading detected during calibration that must be dropped below to consider the sensor triggered. At 0.9, this means that by default the reading must be 10% lower than the known maximum for the sensor to be triggered. Lowering this value will make your air sensors less sensitive, which can help stop them spamming. Increasing it will make your sensors more sensitive - although at 0.9, there isn't a lot of leeway to make the sensors more sensitive by default.
During power on, both the touchboard and the air sensors will automatically calibrate. This process is indicated by the lights flashing between red and purple. This is an indication that you should remove your hands from the board. The lights will then turn red while calibration occurs. Once it is complete, the lights will briefly flash green to show that the board is ready, then move to yellow, indicating the board is active and ready for input. Pressing a key will then turn it pink.
By default, the program will run in NKRO Keyboard mode. The specific keyboard keys are set in USBOutput.cpp, but are listed here in order of left to right:
a z s x d c f v g b h n j m k ,
When a second finger touches the pad, the following keys are pressed in order of left to right
1 q 2 w 3 e 4 r 5 t 6 y 7 u 8 i
By default, the air sensor functions as follows:
Homeis held as long as any sensor is triggered and released when there are no sensors triggered.Endis pressed when any motion is detected, as long as the hand was previously in front of the sensors.Page Upis pressed and released when the sensor detections movement upwards.Page Downis pressed and released when the sensor detections movement downwards.
If #define IR_SENSOR_KEY is uncommented, each air sensor will report back individually. The default binding from bottom to top is:
/ . ' ; ] [
Per US QWERTY layout.