This page contains some miscellaneous notes about wiring on the [KR01] robot, included specifically
so that the robot can be disassembled and reassembled without confusion about which wire goes where.
[{TableOfContents}]
!! Overview
The KR01 is currently using up most of the available GPIO pins, with a bunch being used
by the [Mini PiTFT display|AdafruitMiniPiTFT] (which is optional). In the future we may offload the four encoder
pins to the daughterboard containing the [ItsyBitsy M4 Express]. Most IO connections are
planned to use the [I2C] bus.
We're not currently planning to use the PWM (pulse-width modulation), SPI, Serial (UART)
or other GPIO features, just digital IO.
!! I2C Bus
{{{
► i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- 14 15 -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- 28 -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- 68 -- -- -- -- -- -- --
70: -- -- -- -- 74 75 -- 77
}}}
* 0x14 : UltraBorg servo/ultrasonic controller
* 0x15 : ThunderBorg motor controller
* 0x28 : BNO055 9 DoF sensor
* 0x29 : VL531X ToF sensor
* 0x48 : ADS1015 AD converter
* 0x68 : PiJuice UPS
* 0x74 : starboard RGBMatrix5x5
* 0x75 : 11x7 LED Matrix
* 0x77 : port RGBMatrix5x5
!! GPIO Pin Usage
%%small
|| PIN || PIN
| %%org 3V3 %% | %%red +5V %%
| __02__: SDA (I2C) | %%red +5V %%
| __03__: SCL (I2C) | %%grn GND %%
| __04__ | __14__: TXD0 %%prp STATUS LED %%
| %%grn GND %% | __15__: RXD0 %%prp PIR SENSOR %%
| __17__: %%prp ENCODER A2 STBD %% (white) | __18__: %%prp ENCODER B2 STBD %% %%gry (PCM_CLK) %% (violet)
| __27__: GPIO 27 (unused) | %%grn GND %%
| __22__: %%prp ENCODER A1 PORT %% (grey) | __23__: %%prp ENCODER B1 PORT %% (blue) %%sup † %%
| %%org 3V3 %% %%sup † %% | __24__: GPIO 24%%sup † %%
| __10__: MOSI%%sup † %% | %%grn GND %% %%sup † %%
| __9__: MISO%%sup † %% | __25__: GPIO 25%%sup † %%
| __11__: SCLK%%sup † %% | __8__: CE0%%sup † %%
| %%grn GND %% | __7__: CE1 %%prp UPPER BUMPER %%
| %%gry ID_SD %% | %%gry ID_SC %%
| __5__: %%prp PORT SIDE INFRARED %% | %%grn GND %%
| __6__: %%prp PORT INFRARED %% | __12__: %%prp STBD SIDE INFRARED %%
| __13__: %%prp STBD BUMPER %% | %%grn GND %%
| __19__: %%prp CENTER BUMPER %% | __16__: %%prp STBD INFRARED %%
| __26__: (unused: conflict with SPI) | __20__: %%prp CNTR INFRARED | BUTTON %%
| %%grn GND %% | __21__: %%prp PORT BUMPER %%
%%
%%small
† part of cable assembly connecting to [Adafruit 320x240 TFT Display|Adafruit320x240TFTDisplay] \\
‡ part of cable assembly connecting to MiniTFT display
%%
For sensor wires, wire markings are orange or red for port, green for starboard (just like on a boat).
GPIO pin 20 is reserved for something, I can't remember.
{{{
► pinout
,--------------------------------.
| oooooooooooooooooooo J8 +====
| 1ooooooooooooooooooo | USB
| +====
| Pi Model 3B V1.2 |
| +----+ +====
| |D| |SoC | | USB
| |S| | | +====
| |I| +----+ |
| |C| +======
| |S| | Net
| pwr |HDMI| |I||A| +======
`-| |--------| |----|V|-------'
Revision : a02082
SoC : BCM2837
RAM : 1024Mb
Storage : MicroSD
USB ports : 4 (excluding power)
Ethernet ports : 1
Wi-fi : True
Bluetooth : True
Camera ports (CSI) : 1
Display ports (DSI): 1
J8:
3V3 (1) (2) 5V
GPIO2 (3) (4) 5V
GPIO3 (5) (6) GND
GPIO4 (7) (8) GPIO14
GND (9) (10) GPIO15
GPIO17 (11) (12) GPIO18
GPIO27 (13) (14) GND
GPIO22 (15) (16) GPIO23
3V3 (17) (18) GPIO24
GPIO10 (19) (20) GND
GPIO9 (21) (22) GPIO25
GPIO11 (23) (24) GPIO8
GND (25) (26) GPIO7
GPIO0 (27) (28) GPIO1
GPIO5 (29) (30) GND
GPIO6 (31) (32) GPIO12
GPIO13 (33) (34) GND
GPIO19 (35) (36) GPIO16
GPIO26 (37) (38) GPIO20
GND (39) (40) GPIO21
For further information, please refer to https://pinout.xyz/
}}}
!! Port-Front Board (with BNO05 DoF and [ItsyBitsy M4 Express])
5 pin header:
| %%red +5V %% | SCL | SDA | NA | %%grn GND %%
!! Starboard-Aft Board (connections to below)
| [{Image src='attach/KR01WiringNotes/starboard-aft-connections.png' width='400' caption='Starboard Aft Boar' align='left'}] | [{Image src='attach/KR01WiringNotes/starboard-aft-board-v2.png' caption='Starboard Aft Board' align='right'}]
Mounted on the chassis, an [Adafruit Perma Proto Bonnet|https://www.adafruit.com/product/3203] serves to collect the various power and sensor connections into three connectors: one six pin connector comprising the first six GPIO pins (including 5V, 3.3V, Ground, SDA and SCL), and two ten (2x5) pin connectors. These are commonly called ''Dupont Connectors'', bespoke cables made using dual row wire housings (see [Small Dual Row Wire Housing Pack for DIY Jumper Cables|https://www.adafruit.com/product/3143]).
The upper __Starboard-Aft Board__ board provides two 10 pin connections to the lower board, which includes: the outputs from the bumpers (BP, BC and BS); infrared sensors (IRP, IRC and IRS); motor encoders (A1, A2, B1 and B2); indicator LED; and bypass/switched 5 volt sensor supply.
The color-coding of the jumper wires from the Starboard-Aft Board is as follows:
|| Color || Connection || GPIO Pin
| Purple | Port Bumper | 13
| Blue | Center Bumper | 19
| Green | Starboard Bumper | 26
| | |
|| Color || Connection || GPIO Pin
| Orange | Port Infrared | 12
| Yellow | Center Infrared | 6
| Green | Starboard Infrared | 5
| | |
|| Color || Connection || GPIO Pin
| Blue | Encoder A1 Port | 22
| Purple | Encoder A2 Starboard | 27
| Grey | Encoder B1 Port | 23
| White | Encoder B2 Starboard | 18
!! ItsyBitsy M4 Express & BNO055 Daughterboard
[{Image src='attach/KR01WiringNotes/daughterboard-02.jpg' caption='ItsyBitsy M4 Express & BNO055 Daughterboard' align='center'}]
Earlier I'd experimented using a Perma-Proto board dedicated to holding an [ItsyBitsy M4 Express] and a [BNO055 9-Axis Absolute Orientation|BNO055ImuSensor] sensor. The various connections to and from the daughterboard are shown in the above photo. The two columns of cyan and magenta-coloured pins are used to explode the 5V supply, which are used for the bumper and infrared sensors.
This board is currently not functional. The BNO055 is theoretically incompatible with the Raspberry Pi (the I2C bus speed needs to be slowed), so the ItsyBitsy was used to drive the BNO055 (and potentially poll other sensors). It seems the BNO055 is working okay with the Pi so lately I've just been connecting it directly.
More experiments are in order.
----
[{Tag KR01}]